Author Topic: Making a small marine steam engine the beginners way.  (Read 12491 times)

Offline Gas_mantle

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Making a small marine steam engine the beginners way.
« on: February 07, 2016, 07:12:12 PM »
Hi all,

Although I've been a member here a while now I have yet to post any build work but have decided now to give it a go. I'm a beginner to this hobby and so far have only made very simple wobbler engines and  now just about finished making Stewart Harts' Potty mill engine.

I don't have a mill yet but expecting to buy one in the next few weeks so needed a simple project to tide me over for a while till I get a mill - I decided to have a go at making a small twin cylinder double acting marine style engine.

The engine will be to my own design - I've got an idea in my head how it will look but other than that I'm just going to make it up as I go along - Stewarts' cylinder and valve design for the Potty mill worked well so I intend to broadly stick to something similar with different dimensions.

As this is all fairly new to me I'd really appreciate any advice / tips as well as criticisms or prompts if you think I've overlooked something etc.

At the moment I've damaged the standard lens on my camera and having to use a zoom for now so please forgive me if the images aren't great.

So here goes -

I decided on cylinders made from aluminium and wanted flanged ends to mount the from below and to secure the cylinder heads. I didn't photograph turning the main body as it's fairly self explanatory, the first step of any challenge was to machine a flat face to accept the valve chest.

As I don't have a mill I chose to take facing cuts with the cylinder mounted across the chuck, I kinda don't like doing this but the  home made tool in the picture is pretty effective :-



Once near to size a small boring bar enable me to get close to the flanged ends without fouling up :-



Once turned the cut just left a small radiused edge to file out by hand - the first photo shows the left one done and the right one still to file :-



My initial idea for the valve chest was to just use 1" square aluminium but the proportions didn't look good and would have meant cutting deeper on the cylinder flat to accommodate the wider chest - I decided to slightly narrow them by again facing across the chuck to get 21mm x 25mm chests. :-





At little filing later we have both cylinders and valve chests cut to size ready for drilling.



Not exactly precision engineering but overall I'm quite happy with the start :-)

Peter.



« Last Edit: February 20, 2016, 09:02:28 AM by Gas_mantle »

Offline crueby

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Re: Making a small marine steam engine the beginners way.
« Reply #1 on: February 07, 2016, 07:45:09 PM »
Nice start! Clever way to do the flats without a mill.

How are you going to bolt the valve chest to the cylinder bodies? Hard to tell from those angles, enough depth left on the bodies to drill and tap before the bore? How big are the cylinders?

Will be watching along!    :popcorn:

Offline zeeprogrammer

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Re: Making a small marine steam engine the beginners way.
« Reply #2 on: February 07, 2016, 07:50:33 PM »
Pretty neat. Like Chris said...clever.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #3 on: February 07, 2016, 08:02:39 PM »
Hi,

It's a bit deceptive from the camera angle but I should have sufficient depth to drill and tap holes in the cylinder wall - at the very thinnest part the wall is about 3.5mm opposite the machined flat but with the bolts off the centre line of the chest I will be drilling into a deeper part of the cylinder wall (I hope !).

The cylinder bore is 24mm and the stroke will be 32mm (or possibly a couple of mm less depending how deep I make the piston).

I'll possibly get the pistons made and the cylinder ports drilled tomorrow.

Peter.

Offline Kim

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Re: Making a small marine steam engine the beginners way.
« Reply #4 on: February 08, 2016, 02:21:42 AM »
Very ingenious indeed!

I got a little attachment for my Taig lathe that let me do some milling like maneuvers.  That tided me over for some time before Santa brought me a mill.  Is there any thing like that available for your lathe?  Might be worth a look.  Though it looks as though your getting on just fine without it :)

Kim

Offline b.lindsey

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Re: Making a small marine steam engine the beginners way.
« Reply #5 on: February 08, 2016, 02:23:05 AM »
Nice start Peter, the cylinders look good.

Bill

Offline crueby

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Re: Making a small marine steam engine the beginners way.
« Reply #6 on: February 08, 2016, 03:46:14 AM »
Very ingenious indeed!

I got a little attachment for my Taig lathe that let me do some milling like maneuvers.  That tided me over for some time before Santa brought me a mill.  Is there any thing like that available for your lathe?  Might be worth a look.  Though it looks as though your getting on just fine without it :)

Kim
Think I've seen that, some sort of vertical slide for the cross slide table? Do you have a picture of it?

Peter, cylinders are bigger than they looked in the pics, should be fine for bolts. Nice start!

Offline Jayville

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Re: Making a small marine steam engine the beginners way.
« Reply #7 on: February 08, 2016, 03:49:13 AM »
looking good ...I have a small mill but would think about doing the same if the need arises..keep the good work going ...interested to see how the engine works out..I too am a fan of the small marine engines .....clem

Offline Kim

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Re: Making a small marine steam engine the beginners way.
« Reply #8 on: February 08, 2016, 05:26:28 AM »
I got a little attachment for my Taig lathe that let me do some milling like maneuvers....
Think I've seen that, some sort of vertical slide for the cross slide table? Do you have a picture of it?

Yes, exactly that Chris.  Here's a link to the Taig accessory page for the Milling attachment for their lathe (that's the little lathe I have. Used to be all I had till I got my Grizzly).

http://www.taigtools.com/c1220.html

Don't know what kind of Lathe you have, but if you can figure out a way to mount it on your cross slide it could work for small things.

Kim


Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #9 on: February 08, 2016, 06:30:02 AM »
Thanks for the positive feedback everyone  :)

As for the milling attachment I did consider one, I put it off for a while to see how serious I was about this hobby - I've only had my lathe for 7 months and wasn't sure how I'd manage in this new hobby. Fortunately now I've bought most of the essential tools I need and despite a few minor setbacks with my models I'm confident I'll stick at it so have decided to go the whole way and buy a mill.

Here in the UK the model I want from the same supplier as my lathe is about 600, it seems to be a popular machine and will be large enough for the work I'm likely to do so I intend to buy one in the next few weeks. I think there is a possibility I'll finish this engine before I get the mill but if not I will finish it just using my lathe. I suspect there are quite a few beginners out there like myself who don't yet have access to a mill and are looking for something relatively simple to build that can be made using just a lathe so I'd like to have a go at creating one.

I was first attracted to Stewart Harts' Potty mill engine as it is designed to be built without a mill and hopefully this will be the same. Incidentally I've just about completed the Potty engine and got it running nicely and I'd thoroughly recommend it to another beginner. All I need to do is paint it once the materials I've ordered arrive then I'll post a video of it running.

With a bit of luck I'll get the pistons done today - I ordered some silicon 'O' rings as piston rings as an afterthought whilst buying something else so it meant I'd already bored out the cylinders when they arrived but they seem to be a good match (possibly very slightly too tight). I'll experiment a bit with the fit today in the hope I can use them.

I've considered using 2 rings per piston and cutting the piston slightly undersize so only the rings touch the walls - does this sound a good idea ? I've never used the 'O' ring method before, having previously just used rolled up PTFE tape so wasn't really sure about the fit I should be aiming for.

Many thanks
Peter.
« Last Edit: February 08, 2016, 06:33:07 AM by Gas_mantle »

Offline paul gough

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Re: Making a small marine steam engine the beginners way.
« Reply #10 on: February 08, 2016, 07:37:44 AM »
Hi Peter, What a great way to enter engine building and design in one stroke. You may be a 'beginner' however moving to designing and machining utilising stock materials is a pretty sophisticated path. You certainly show confidence and ability as designing and making experimental or prototype engines is often where  accomplished model engine makers finish their days. A while back a selection of small aluminium 'steam' designs was highlighted in the Australian Model Engineering magazine, the work of a man into his eighties, thus a creative expression of a person of great experience and knowledge.

About the only thing I can think of that may help you at the moment, supposing you intend to run your engines on steam, is to keep in mind the effects and consequences of temperature with respect to your materials. Steam and air are a bit different. Regards, Paul Gough.

Offline Garry_C

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Re: Making a small marine steam engine the beginners way.
« Reply #11 on: February 08, 2016, 09:33:13 AM »
Good to see you putting this up on here Peter and you've made a great start - I'll be following as well..  :ThumbsUp:
Cheers
Garry.

Online Jasonb

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Re: Making a small marine steam engine the beginners way.
« Reply #12 on: February 08, 2016, 09:50:01 AM »
If your o rings are sized correctly they should be a bit larger than the bore say 24.4mm OD as they need to be squashed slightly to seal.

You may get away with using one ring, the last three engines that I have done I have cut grooves for two but only needed to use one ring.

If only running on air then 0.001" smaller piston will be fine. Infact as the cylinder is aluminium the same clearance will do for steam, its only when you have an ali piston in iron or bronze that you need more clearance for the piston to expand.

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #13 on: February 08, 2016, 10:25:38 AM »
Thanks Jason, it sounds like the rings I have will be fine then, they require just a very slight persuasion to fit the bore, I intend to make the pistons from brass.

I'll probably do like you did and cut 2 grooves even if I only use 1 - a lot will depend how deep I make the piston - there's probably going to be a lot of trial and error with this engine till I can figure out what works and what doesn't  :)

Peter

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #14 on: February 08, 2016, 02:47:12 PM »
Hi,

I didn't do the piston as originally intended but managed to get one of the valve chests drilled out - the paints for my Potty mill engine have now arrived so I'll make a start on that later.

Anyway although there isn't really a lot to show with the valve chest I did take a few photos in the hope that less experienced members like myself can understand how this engine will (hopefully) work.

Essentially it's a small spool valve design with a 'dog bone' shaped piston oscillating within a cylindrical bore to open and close the ports as necessary. In my previous engine the 'transfer' passages (or whatever they are called) were drilled within the cylinder wall but this time I've decided to drill then within the valve chest itself. I'm not sure this will offer any improvement but it will allow me to drill a larger passage and I wanted to see how well it works.

First things first - Drill the main spool valve bore, I settled on 7mm as a start point (with a bit of room to open it out later if necessary), then drill the inlet hole to meet it :-



I then drilled another couple of holes as the exhaust ports before proceeding with the 'transfer passages'. These will follow parallel with the valve bore and take the steam / air to the cylinder ends. I want them to exit the valve chest within the cylinder flange where I'll cut 2 small cross passages into the cylinder. It is my intention to make a close fitting hollow sleeve to form an airtight connection between the ends of the valve chest and the cylinder flanges.

These passages will stop just short of halfway along the steam chest and meet with 2 crossholes leading from the valve bore.



In the photo below the cross holes leading from the valve can be seen - these will be plugged to form an airtight seal later.



I'm hoping this is making sense ! It seems a very round about way of doing something but hopefully the following 2 photos make it clearer  :)

The 2 holes on the left are the exhaust ports, the 2 on the right are the ones that will be plugged, on the wide face hidden from view is the single inlet hole - the transfer passage bores are currently 3mm but having relooked at it I think they may need opening out a bit.



Showing the other side of the chest with the inlet and the transfer passage within the flange.




If you can understand all that you are a better person than me  :headscratch:

Peter.







Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #15 on: February 20, 2016, 02:49:10 PM »
Having now just about completed another little engine I've been working on I've now been able to get at bit more to this project. I had originally thought about doing the cylinder end cover next but instead made the pistons and just about completed one of the valve chests.

I needed to plug 2 holes leading from the valve cylinder to the long transfer passages and settled on making 3mm aluminium plugs to be hammered in and sealed with a drop of Loctite 638, once filed down flush they seem to offer a good seal that is hardly noticeable - they can just about be seen on the left hand one.

]



I decided to open out the existing 3mm transfer passage to 4mm and also drill a shallow 5mm diameter cavity at either end - this will allow me to add a sealant where the passage bridges the gap into the cylinder flange. I also reamed out the 8mm valve cylinder at the same time.



My original intention for securing the valve chest to the cylinder was to use 8 M2.5 bolts but I find them a bit unreliable when tapping small holes into aluminium where the threaded hole isn't going to be very deep - I've decided I can just about get away with M3 but will use studs as I think there will be less chance of damaging the threads in the cylinder wall. Now that the air passages are located inside the valve chest a really close airtight fit isn't essential but M3s should give me a suitably secure fit.



So far so good, just need now to drill the cylinder, secure the chest then drill the flanges and seal so ought to
have one cylinder / valve assembly completed tomorrow.

And there we have it  - looking rather like a small aluminium toilet bowl  :)



Peter.

Offline Kim

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Re: Making a small marine steam engine the beginners way.
« Reply #16 on: February 20, 2016, 03:58:08 PM »
Nice work on the plugs Peter, hardly noticeable at all!
Your tiny toilet bowl looks great to me! :)
Kim

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #17 on: February 21, 2016, 08:11:33 PM »
Hi,

I've managed to get a little bit further and so far so good.

It was my intention to drill and tap the cylinders the secure the chest with bolts but after a rethink I decided to cut the heads off some bolts to make studs and Loctite them into the cylinder. I want the cylinder / valve to be a permanently attached fully airtight 1 piece unit once completed.

I did drill for 8 studs but even with 4 and Loctite it is incredibly strong fit so I'll stay with 4 and use dummy studs in the other 4.



Now with the valve chest fixed in place the next job was to make an airtight seal at the join between the chest and cylinder flange, I've never used JB Weld before but after reading good reviews I gave it a try. Having plugged both ends with the epoxy mix once hardened it was a simple matter to reopen the steam passage and cut a small groove leading to the cylinder bore. The JB weld was more runny than I expected and I did worry that it would flow all the way down the passage and block the small hole into the valve bore. Fortunately this didn't happened and after a few tests flushing air / water through it I'm satisfied there is an unobstructed flow through out.

I cut the passage to the cylinder using my trusty old 10 Woolworths dremmel type tool so it's not particulary attractive but should be functional and hopefuuly means I've now got my one piece leakproof valve / cylinder assemply.



Next task was the simple enough cylinder covers, I want to dispense with crosshead guides so have opted to have the piston rods passing right through the cylinders - It's not intended to be any kind of replica engine so I'm not concerned if it gives a slightly unusual appearance - the moving piston rods may even add a bit of visually interest when the engine is running.

I wasn't really sure of the best order to machine the covers but wanted the piston hole drilled from the same lathe setting as the cylinder locating spigot so settled on doing the outside face first.

The next image will become the top of the cylinder head but because I want the piston rod hole drilled from the other side Ive only gone in about half the required depth to take an M8 thread for the piston rod guide.



Having now parted off and turned the part round I can turn the spigot side. At this point I drilled through and reamed to 4mm for the piston rod and hopefully if I set it up right it will meet the hole on the other side centrally. I'd be interested how other more experienced members would have made this part as I'm sure there must be an easier way to do it.



As it happened it turned out quite well, the central hole lines up nicely and at least now the locating spigot should ensure it runs true to the cylinder centre line.

Overall I'm reasonably happy with it, the flanges and cylinder covers are maybe a bit on the thick side but I'll have to get used to it. What was looking like an aluminium toilet is now resembling a fire hydrant !



With a bit of luck I might be able to try it connected to an airsupply tomorrow and see if the piston will respond to the valve in one direction at least.

Peter.





Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #18 on: February 23, 2016, 10:24:52 PM »
Hi,

Having now made both cylinder covers and the 'dogbone' spool valve for one of the cylinders the next job was to fit the covers and give the assembly a crude test on my airbrush compressor. I would have made sense to make 4 covers etc at the same time but I wanted to see how the cylinder performed before going further.

Without a rotary table or dividing head I used a crude method with a spirit level and surface gauge on the jaws of my 3 jaw chuck to get the 60* spacing for 6 retaining holes - Ive settled on M2.5 with enough room to go to M3 if need be later.



I made 2 brass piston rod guides that will retain PTFE tape to give an airtight seal and added paper gaskets.



With a few temporary bolts holding everything together I've been able to test it and pleased to say it works well without leaks and responds to the valve very well  :)



Satisfied it will work ok I can now concentrate on completing the second cylinder assembly.

Peter.




Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #19 on: March 01, 2016, 12:56:52 PM »
Hi all,

I've now managed to almost complete the 2nd cylinder and valve assembly and all the need now is the plumbing fixtures and a bit of final tidying up. It seemed logical to next make the supporting plate for them to attach to.

I've only ever used my faceplate once before to practice on a bit of scrap so this was actually the first proper use of it and found it awkward although things did ultimately turn out well. I settled on using a piece of 6mm thick steel 140mm long it only just cleared the lathe bed when the offset was positioned - a bit of steel bar worked well as a wobbler bar for centering but getting the dial indicator positioned to miss the mounting hardware proved awkward.



Once bored out and mounting holes drilled everything seems to be looking ok.



So far I'm quite pleased with the result, they both work well on an airline so hopefully these 2 bad boys will have a bit of guts when running  :)



I'll possibly make a start on the crank shaft tomorrow.

Peter.

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #20 on: March 05, 2016, 07:43:19 PM »
Hi,

With the cylinder / valve assemblies now almost complete I decided to make 2 simple brass valve guides and set about making the crankshaft. I don't have the experience to make the shaft from a solid piece so I've opted to make one from 10mm silver steel and EN1a steel webs.

With 50mm dia webs and a 20mm throw I had to make do with 6 mm cranks pins although 8mm might have been better, I had originally turned to size 2 of the discs then decided for the remaining 2 I'd mount them all on the shaft and turn them together, my thinking was to ensure they are all exactly the same and enable accurate drilling later.




Although it eventually worked well I did seem to make more work for myself



With them all exactly the same and bolted together I was able to drill all the crank pin holes together.



All I need to do now is mark out and cut the webs to create a weighted side and secure them nearer to completion. I'm not sure wether the proportions of this project are working out right but it's starting to take shape and too late to alter things.

Finally a shot showing the work so far with the valve rod guides in place  :)

]

Peter.


« Last Edit: March 05, 2016, 08:02:46 PM by Gas_mantle »

Offline burnit0017

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Re: Making a small marine steam engine the beginners way.
« Reply #21 on: March 05, 2016, 08:00:13 PM »
Hi, thanks for posting. I am learning a lot. Thanks again.

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #22 on: March 08, 2016, 09:11:10 PM »
Hi all,

I decided to leave the cutting of the crank webs for now till I have a think about the proportions and how to mark them out so instead I set to work making the crossheads and big end bearings.

For the crossheads I used 15mm square steel bar and began with cutting a small raised top and small chamfers then drilling and tapping a 4mm thread.



I didn't make a very good job of chain drilling the slot and left myself with a lot more filing than I should have.



With 15mm dia filing buttons made I set about radiusing the ends and opening out the central slots, fortunately things turned out reasonably well.





Next, on to the big end bearings.

Since it is a closed crankshaft I need split bearings and wasn't really sure of the best way of going about it but started with 5/16 x 1" steel for the top.



When it came to turn it around to face the other end parallel I didn't leave much to hold onto.



2 pieces of  5/16 square brass will form the bearing halves and another piece of steel for the foot so onto the drilling.



While checking the alignment with silver steel rods I decided I'd thread them as the final fixings rather than M3 bolts that I had originally intended.



The intention next is to turn the 4 bolted together parts in the lathe as 1 item to achieve even radiused sides but I forgot to mark the centre line of the steel foot and the sides are uneven hacksaw cut edges. The only way I could see to find the centre line with some degree of accuracy was by supporting the whole assembly on a close fitting rod then mark as best I can where I estimate the centre to be with a scribing block.



Again using the scribing block and the estimated centreline I'm hoping it's positioned right to turn the sides and part off from the waste material in the chuck.



With the centre hole drilled and reamed I got there in the end :-)

Just needs a bit of fine filing to ensure the side faces are perfectly even when positioned it the crank web and all seems ok.



I'm sure there must have been an easier and more accurate way of doing it - now just got to complete the second one tomorrow.

Peter.









Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #23 on: March 16, 2016, 12:24:17 PM »
Hi,

Over the last few days I made a start on the crank webs and crankshaft bearings, what started out ok is now turning out not so good  :(

For the crank webs I wanted a weighted design, I guess on a small engine like this it probably won't make a lot of difference to it's running and I can only make a guess as to what shape they need to be but I thought they'd make the engine look a bit more attractive.

I started off by roughly marking out the profile and drilling holes for the radiused corners, getting the proportions to look acceptable took a few goes and I wanted to make sure the crank pin side was at least as wide as the big end bearing, so after a lot of guess work I decided this was about as good as I was likely to get



So I drilled the remaining discs and filed them as a single unit bolted together.





After a lot more filing I arrive at this quartet, they still need a bit of slightly evening up and the finishing improving but I'm reasonably happy with the result and if they do actually assist in the balancing of the engine it's a bonus.



With webs about done I'm now in a position to determine roughly how high the crankshaft needs to be and set about making the 4 supporting bearings and it all goes downhill from here  >:(

I really had no idea how best to go about making them but as it is a closed crankshaft I wanted split bearings and was mindful of getting them all exactly the same height. Settling on 5/16 steel for the bases I roughly turned part of the sides parallel and made a centre mark as a future reference should I need it later.



Doing all 4 bases the same way I turned them round in the chuck and faced off the other ends in one go to hopefully get them all exactly the same height.



With hindsight I should have realised this probably isn't going to be the best way of doing it but it seemed ok at the time, the intention was to get 4 bases having both ends parallel, the sides radiused part way and all the same size to hold in the chuck later (these radiused sides are ultimately to be waste material and only to aid centring in the chuck).



Once drilled and 5/16 brass bearing blocks added it should now be a simple matter to turn the sides parallel. With the steel bearing top centre drilled and the other end of the work piece held by the machined radiused waste not much can go wrong, or so I thought.



Clearly I've gone wrong some where at the finished article looks like the Leaning tower of Pisa.



Admittedly there is the waste material to take of the bottom and reface it and I can thin down the top steel bar a bit but there is still a slight skew. I should imagine it would still run ok as the crankshaft does turn nicely and the hole does appear nicely parallel to the sides and base but I'm reluctant to use the same method to make the other 3.



It's not the end of the world and it is a learning curve but if anyone has any comments or ideas of how to go about making the other 3 I'd be really grateful as at the moment I'm completely stuck..

Many thanks
Peter.




« Last Edit: March 16, 2016, 03:55:43 PM by Gas_mantle »

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #24 on: April 08, 2016, 03:31:34 PM »
Hi,

Having been a tad under the weather recently I haven't gotten as much done as I would have liked nor have I taken many photos but for the benefit of anyone following this simple build I thought I'd update it with the progress so far.

I decided to abandon the crank bearings I was making and after a bit of advice from other members I opted to remake them a lot shorter and improve on the accuracy. The second attempt is a vast improvement :-



With the crank fitted next job was to start on the 6 supporting pillars, I've done 3 so far and at least it gives me some idea of how the model is starting to look - the following 2 photos show the progress to date and so far I'm reasonably happy with how it's taking shape.

I'd have liked it to be a bit shorter but with hindsight I think I should have made the pistons stroke smaller - it's a bit late now so I'll have to learn to live with it.

It looks like the cylinders don't sit right but it is just that they weren't secured in place when I took the photos and I had noticed they weren't seated correctly.





The cylinders operate nicely on an airline and the crank turns nicely so I'm hoping with a few minor adjustments nearer to completion it should be a runner :-)

Peter.

Offline sbwhart

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Re: Making a small marine steam engine the beginners way.
« Reply #25 on: April 14, 2016, 06:46:41 AM »
That's coming on well Peter i like how you made the bearings and crank shaft.

 :ThumbsUp: :ThumbsUp: :ThumbsUp:

Keep up the good work

Stew
A little bit of clearance never got in the way

Offline zeeprogrammer

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Re: Making a small marine steam engine the beginners way.
« Reply #26 on: April 14, 2016, 11:06:51 AM »
Glad you're feeling better Peter.

I like those columns. (Whole thing looks good.)
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Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #27 on: April 14, 2016, 11:21:37 AM »
Thanks for the feedback guys  :)

It does turn with quite a bit of power on an airline but there are still a few tight spots to sort out, I may have to remake one of the crossheads which is causing some of the tightness if I can't correct things with a bit of filing.

It's funny you mention the supporting pillars, I thought the were too plain and wanted to make tapered ones but the topslide on my little machine doesn't have enough travel and I wasn't confident I could make a decent job using other methods.

I've made the rest of the pillars now and will update it in a few days time when I've got somewhere with the flywheel or the eccentrics ( not yet decided what to do next)

Peter.

Offline cfellows

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Re: Making a small marine steam engine the beginners way.
« Reply #28 on: April 14, 2016, 03:07:22 PM »
Nice looking build, Peter.  You do some nice work.

Chuck
So many projects, so little time...

Offline Bikerbob

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Re: Making a small marine steam engine the beginners way.
« Reply #29 on: April 27, 2016, 04:43:54 PM »
Peter

I am in the process of designing a model engine and found your approch to the steam chest appealing. Could you sketch all the passages in the steam chest and email to me <email address removed>
Thank you
Bikerbob

Edit Jo: Bob please send Peter a PM with your Email address rather than posting it openly on the forum. Web bots have a nasty habit of picking up Email addresses printed in the open and sending you lots of spam  :ShakeHead:
« Last Edit: April 27, 2016, 05:27:35 PM by Jo »
Bikerbob

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #30 on: April 28, 2016, 01:52:02 AM »
Yes Bob I'll do that if you message me your details.

I'm not familiar with Cad drawing programs though, will a few hand drawn sketches photographed do ? I'll add a few explanatory notes too.

Funilly enough for a bit of a fag packet design they work well without any leaks.

Peter.

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #31 on: May 31, 2016, 03:44:04 PM »
Hi,

I can happily say that now I've made the eccentrics and got one side of the flywheel machined the engine is now nearing completion.

I've tried it running on a small air compressor and both cylinders work well, as yet I haven't made an inlet manifold or a splitter for my airline so I've only been able to test one cylinder at a time but either of them running alone will easily operate the engine without the flywheel yet in place.

It's not perfect by any means and has a couple of tight spots yet to sort out but I'm reasonably satisfied with the result even if it is a bit unorthodox looking - I guess that's how things turn out when you make it up as you go along.

The first picture looks to be leaning because of the camera angle and the uneven length of the protruding bolts on the underside, but it is actually vertical - honest :-)



So far the flywheel is only done on one side and I had a lot of hassle trying to cut the recess but with a bit of luck it will be finished tomorrow.



Just need to make a bearing to support the crank beyond the flywheel and finish of with a few small fittings and decorative extras then it should be ready to clean up and paint :-)



Peter.



Offline Alan Haisley

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Re: Making a small marine steam engine the beginners way.
« Reply #32 on: May 31, 2016, 04:13:44 PM »
Peter,
It looks like you have plenty of room to fit cross-head guides and with the short connecting rod throw it's probably a good idea to do so. Without guides fitted I think that the piston rods will rapidly wear the glands and cost you half your power.

Other than that, I love your work and think that you did a marvelous job for an essentially first engine to your own design.


 :cheers:
« Last Edit: May 31, 2016, 06:12:09 PM by Jo »
Near Raleigh, NC, USA

Offline pgp001

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Re: Making a small marine steam engine the beginners way.
« Reply #33 on: May 31, 2016, 07:38:05 PM »
Don't forget that Peter has built this without using a milling machine, and he doesn't have a workshop as such (its in a corner of his kitchen) so its quite an achievement really.

He came to Doncaster exhibition with me a couple of weeks ago and bought a milling machine from there, so once it arrives it will be interesting to see what he conjures up next.

Phil

Offline zeeprogrammer

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Re: Making a small marine steam engine the beginners way.
« Reply #34 on: May 31, 2016, 10:54:55 PM »
Wow. That's really coming together.
And I like that flywheel. Particularly the inner holes. I've never done a good job on that.
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Re: Making a small marine steam engine the beginners way.
« Reply #35 on: June 01, 2016, 08:16:59 AM »
Hi,

When I came up with the idea I pondered how to make crosshead guides and thought with the limited tooling and experience I have that I wouldn't be able to make anything accurate enough. I decided that having long piston rods exiting the cylinder caps would be a lot easier and hopefully reduce any wear - it means the engine does have an odd hybrid appearance but for now it is probably the best I can manage. I do agree that guides would be a far better solution though and it's something I have considered adding later. As Phil said I will have a mill shortly and then the possibility of adding guides then becomes more realistic.

As for the flywheel, I've made few smaller wheels in the past and to be honest this is the first one that has looked anything like reasonable. The radial holes were bored by offsetting the wheel mounted on a faceplate and it's about at the limit my small hobby lathe could manage.

Offline pgp001

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Re: Making a small marine steam engine the beginners way.
« Reply #36 on: June 03, 2016, 11:24:35 PM »
Peter

I think it would be good for us all to see a video of your engine once you get it running.
It will show others what can be done with very little equipment.

Phil

Offline b.lindsey

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Re: Making a small marine steam engine the beginners way.
« Reply #37 on: June 03, 2016, 11:45:56 PM »
Peter it looks far better than what I could do with a lathe only. I do think the new mill will open a lot more possibilities for you though. Yes a video please when you can but in any case.... well done!!!

Bill

Offline crueby

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Re: Making a small marine steam engine the beginners way.
« Reply #38 on: June 04, 2016, 12:52:13 AM »
Having the piston rod extend through the top caps rather than using lower guides was a common thing on marine steam engines, keeping them light and compact. The Sabino's Payne engine is that way, been running well for many decades. I think it gives it a nicely interesting action.

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #39 on: June 04, 2016, 01:35:59 AM »
Thanks for the replies I'll try and post a video tomorrow.

As for the piston rods coming out the cylinder tops, I wasn't aware that was common on marine engines, I did it just to get around the problem of making crosshead guides. The engine is about 24mm bore and 40mm stroke which means with the additional height of the piston rods exiting the cylinder heads gives it a very tall look, If ever I was to make another one I'd reduce the stroke.

Initially when I started building it I assumed a longer stroke would lessen any lateral movement on the piston rods, I'm by no means an engineer but having had a rethink I'm now thinking a shorter stroke and a longer conrod would have been better.

With the benefit of hindsight I think the piston rods could do with being 6mm dia, they were originally 4 mm silver steel but I later modified things so they are now 5mm, unless I remake the cylinder ends I can't increase that.

It's far from perfect but I guess this is what happens when you make it up as you go along :-)

Peter.

Offline crueby

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Re: Making a small marine steam engine the beginners way.
« Reply #40 on: June 04, 2016, 02:04:24 AM »
Here is a shot of the engine I did, inspired, not a copy of, by the Sabino passenger steamer engine. The piston rods go through the caps, as do the valve rods. This setup keeps everything straight, no need for crossheads, runs very well and is a fun motion to watch.

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Re: Making a small marine steam engine the beginners way.
« Reply #41 on: June 04, 2016, 01:26:28 PM »
Some traction engines also used front guides in conjunction with some form of crosshead guide.

Its comming along well, look forward to seeing it run

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #42 on: June 04, 2016, 07:34:18 PM »
I've managed to make a short video of the engine running on an airbrush compressor - I'm on my own so it's not the best video but it does at least give some idea of how it runs.   I don't know how to turn the video through 90* so I'm afraid it's side on :-(

Anyway, at the moment the airlines are just a temporary push fit held in with elastic bands and there isn't yet any gland packing so there should be plenty of scope for improvement once it is complete.

It runs reasonably well at the moment but I think the valve timing is a bit out on the right cylinder and I think the valve rod is slightly too short so the valve is a bit low in its travel and possibly meaning the cylinders are slightly fighting against each other. I'm reasonably confident with a bit of tinkering I can get it to run significantly better. I forgot to show in the video but it will operate about as low as 50rpm.

It's still a bit rough and ready and needs a lot more to tidy it up. 1 or 2 of the bearing blocks could do with moving over slightly to even them up and I need yet to add a supporting bearing outside of the flywheel.

<a href="http://www.youtube.com/watch?v=Z9sxFpdytX0" target="_blank">http://www.youtube.com/watch?v=Z9sxFpdytX0</a>

Peter.

Offline Roger B

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Re: Making a small marine steam engine the beginners way.
« Reply #43 on: June 04, 2016, 08:06:32 PM »
Looks good to me  :praise2:  :praise2: You should be proud of that  :ThumbsUp:  :ThumbsUp:  :wine1:
Best regards

Roger

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Re: Making a small marine steam engine the beginners way.
« Reply #44 on: June 04, 2016, 08:37:20 PM »
Thats running well and looks to turn over very smoothly where you were rotating it by hand.  :ThumbsUp:

Offline crueby

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Re: Making a small marine steam engine the beginners way.
« Reply #45 on: June 04, 2016, 08:41:47 PM »
Very nice!!

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #46 on: June 04, 2016, 09:00:51 PM »
Thanks guys :-)

I need to get round the timing problem - either cylinder will easily run the engine on i's own so it kind of suggests they are both set correctly as individuals but when they are both under power the engine runs more slowly - they were both under power in the video.

Is it likely that the timing (or valve position) needs adjusting or does that suggest something else is at fault ?

Offline zeeprogrammer

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Re: Making a small marine steam engine the beginners way.
« Reply #47 on: June 04, 2016, 10:28:21 PM »
Looking great!  :ThumbsUp:

On an airbrush compressor? What kind of pressure was it giving?

For whatever reason, I thought the engine was smaller. The video (i.e. your hands) put it into perspective.
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Offline crueby

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Re: Making a small marine steam engine the beginners way.
« Reply #48 on: June 04, 2016, 10:33:04 PM »
Hmmm... If the timing was off, seems like you would accentuate the problem when just running one one side. Since it is slower with BOTH, I'd suspect the air supply cannot deliver the same pressure and volume when both are going. You mention an airbrush compressor. If it has no tank for a resevoir, that is probably the issue - the compressor cannot put out enough volume to supply both cylinders at the same pressure as just one. Do you have a pressure gauge you can put inline? If so, and if that is the problem, you would see a lower reading when both are connected than just one. That is a pretty good size cylinder, could be eating a lot of air, and airbrush compressors are not known for putting out high volumes.

The engine looks great!   :cheers:

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Re: Making a small marine steam engine the beginners way.
« Reply #49 on: June 04, 2016, 11:16:19 PM »
That looks mighty fine to me Peter. And yes, it is bigger than I had thought but well done all around!!

Bill

Offline pgp001

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Re: Making a small marine steam engine the beginners way.
« Reply #50 on: June 05, 2016, 10:56:19 AM »
There you Peter, I told you everyone would be appreciative and supportive.

The engine is very impressive and looks to run pretty well, I agree with the comment that your compressor might be struggling to keep up though.
I have a bigger compressor if you want to bring the engine and give it a try sometime. The other thing you could do is rig up a reservoir, an old car wheel and tyre would do as a start.
I did that and then progressed onto an old calor gas bottle, prior to getting a bigger compressor.

Phil

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Re: Making a small marine steam engine the beginners way.
« Reply #51 on: June 05, 2016, 11:11:58 AM »
Thanks for the replies everyone,

As for the compressor issue, I hadn't really thought about it till it was mentioned - it hasn't got a tank or a pressure gauge so I'm not sure what it gives out.

At the moment I'm using 8mm ID cheap aquarium air line, it's very thin walled and because the compressor hasn't got a regulator valve it means the tube balloons near the compressor outlet - it is so thin in does actually explode after a few minutes running !  I've got round the problem temporarily by slightly opening another outlet so part of the air vents to atmosphere.  This means of course I am losing some of the pressure.

The fact that the airline swells up up suggests to me it isn't capable of passing the amount of air the compressor can deliver ?  I'm inclined to think a larger bore tube and slightly larger inlets on the engine itself would improve things and allow each cylinder to function better when working together.

It's a sunny day here in Yorkshire so I'm going to have a few hours tinkering with it outside.

Phil I'll see how it performs after a bit of work but if need be I make take up the offer of trying it on your compressor :-)

Thanks
Peter.

Offline gary.a.ayres

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Re: Making a small marine steam engine the beginners way.
« Reply #52 on: September 28, 2018, 09:20:05 AM »
A significant step in your impressively short journey from beginner to skilled engine builder.

Nice one!

 :ThumbsUp:

Offline Ramon

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Re: Making a small marine steam engine the beginners way.
« Reply #53 on: September 28, 2018, 02:27:50 PM »
Hello Peter - I've just caught up with this thread and would like to say a big 'congratulations' on such a fine result and particularly so with the limited resources you had at your disposal. Nothing should inspire people more to have a go than seeing examples such as this. Having good kit is one thing - being able to achieve something like this without it is totally another - well done indeed :ThumbsUp: :ThumbsUp:

Tug
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Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #54 on: September 28, 2018, 02:55:11 PM »
Thanks guys,

To be honest it's a cosmetic disaster, everything is out of proportion and it's just an ugly looking thing. It kinda demonstrates that when you make something without any plans and just rely on what's in your head then things don't always turn out right. It was a great learning curve though and gave me chance to try out a few techniques I'd never used before.

I made it pretty much on the kitchen table using just a small lathe and a few files so I suppose that's my excuse for the way it turned out.  :Lol:

I never quite finished it by adding an extra support bearing outside of the flywheel or a few other details that needed doing. Once I proved to myself it was a runner I cannibalised it to use the barstock on other projects.   ---  R.I.P the ugly marine engine  :D

On the plus side it was a decent little runner though and could give a nasty kick :-


Offline Ye-Ole Steam Dude

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Re: Making a small marine steam engine the beginners way.
« Reply #55 on: September 28, 2018, 04:01:48 PM »
Hello Peter,

From the video it is quite nice looking and a good runner, one that you should be proud of.

Have a great day,
Thomas

Offline propforward

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Re: Making a small marine steam engine the beginners way.
« Reply #56 on: September 28, 2018, 07:04:49 PM »
I second that. To be honest, what Gas_Mantle rates as ugly, kicks my best effort to date into a cocked hat, and that's not an exaggeration.
Stuart

Offline JC54

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Re: Making a small marine steam engine the beginners way.
« Reply #57 on: September 28, 2018, 07:27:13 PM »
Hello Peter,
         As a beginner this motor has given me some ideas to get around some parts that I was not sure of being able to machine. I like the action with the extension through the top of the cylinder, helping to eliminate the need for accurate crosslides . I would not call this motor ugly I just love the action...

Offline Gas_mantle

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Re: Making a small marine steam engine the beginners way.
« Reply #58 on: September 28, 2018, 08:11:36 PM »
Thanks guys,

It's a crude engine and very much a beginner barstock project that I used really as a bit of a learning exercise for myself.

I'd love to be able to build an elaborate model like some of the highly skilled members here but until that's possible I'm happy to post a few simpler builds in the hope someone else new to the game might think 'I can build one of those'.

Learning model engineering from being a beginner isn't going to happen in a week but with some very basic tools and a bit of forum advice it's possible to build very satisfying working engines very quickly. The little engine I made in this thread has a lot wrong with it (hence I cannibalised it) but I think you'll agree it's a decent little runner. The basic idea works so I'd like to think another beginner can look at it and see its an easy build then improve on the design and maybe build something along similar lines.

There's a wealth of great advice on this form and it is all free if you ask, I'd strongly advise any other newbies to post their simpler build logs and ask questions along the way.

The 'Ugly marine engine' would have been a damn sight more ugly without the advice of members here  ;)

Peter.


Offline Jeff123

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Re: Making a small marine steam engine the beginners way.
« Reply #59 on: October 02, 2018, 07:09:22 PM »
Hi Peter,

First time I've looked at this thread, read all the posts in one go!!!!

I like it , well done and I admire your adventurous approach.

I am a beginner and currently designing a small freelance oscillator. like you much of the design is all in my head, hope it turns out as well as yours.

Yes I do intend to start a build log. Still planning at the moment!!

Treat yourself to days fishing as a reward for your endeavours

Geoff :) :)

Offline b.lindsey

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Re: Making a small marine steam engine the beginners way.
« Reply #60 on: October 02, 2018, 08:32:18 PM »
Just catching up and seeing the video.i don't find t it ugly at all and it really runs very well. Nicely done indeed!!

Bill
 

Offline sbwhart

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Re: Making a small marine steam engine the beginners way.
« Reply #61 on: October 03, 2018, 07:54:08 AM »
Hi Peter

Great result it run really well and you use the simple cylinder and piston valve for the very reason I designed it:- for people to mix it up and to use it as the basis of a new engine great work. At some point in the future I want to use it as the basis of a Maudsley table type engine.

Great work  :ThumbsUp: :ThumbsUp: :ThumbsUp: :ThumbsUp:

Stew
A little bit of clearance never got in the way