Author Topic: A portable steam engine  (Read 70355 times)

Offline Stuart

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Re: A portable steam engine
« Reply #15 on: July 27, 2012, 11:21:41 AM »
good work there  Rich


nice to see more copper boiler work


Stuart
My aim is for a accurate part with a good finish

Offline Firebird

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Re: A portable steam engine
« Reply #16 on: July 28, 2012, 09:16:22 PM »
Hi

A bit of progress on the cylinder today. With the help of Sandy C the ports have been worked out.



I wasn't over confident for some reason so decide to have a practice on a bit of scrap steel.



Its a good job I did. The first attempt on the right of the picture was a complete cock up. I had all my moves worked out on paper but obviously got it wrong :embarassed: :embarassed:

The second attempt, on the left of the picture, was ok, I got it right. :) :)

The finished ports came out pretty well on size using a 3/32 and a 3/16 end mill with light cuts at maximum speed on my X1 mill. I was going to use slightly smaller cutters first then open out to size but decided to go straight in with the 3/32 and 3/16.

The cylinder set up and centred in the mill with the 3/16 cutter ready.



The exhaust port cut and the first inlet port finished.



The second inlet port cut. I have used the 3/32 cutter to square of the corners of the exhast port.



The cylinder turned sideways and cross drilled 4mm



Then drilled and tapped  1/4 X 40



A test fit of a spare brass adapter. (not the one I will use)



A pocket is machined into the ends of the cylinder 3/32 X 5/16 using a 3/32 end mill



The mandrel I made earlier is used to hold the cylinder and set it up at an angle.



Then 2 X 3/32 holes are drilled from each pocket into the inlet ports.







You can just see the holes in the top port.



Heres one for Carl, looking down my shop this afternoon.



Cheers

Rich
« Last Edit: July 28, 2012, 11:09:25 PM by Firebird »

Offline zeeprogrammer

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Re: A portable steam engine
« Reply #17 on: July 28, 2012, 10:57:15 PM »
Thanks Rich!

I was just talking to T (wife) about the shop of my dreams (retirement is not that far off so many of our discussions are around our next home). Windows! Lots of light and a view. Can't stay bent over a machine all the time.

Nice work and, as usual, well documented.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Zee-Another Thread Trasher.

Offline mklotz

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Re: A portable steam engine
« Reply #18 on: July 28, 2012, 11:53:28 PM »
Be sure to provide blinds.  You don't want the dopers to be able to see all those easily-pawnable/resaleable tools.
---
Regards, Marv


Home Shop Freeware
http://www.myvirtualnetwork.com/mklotz

Offline Firebird

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Re: A portable steam engine
« Reply #19 on: July 29, 2012, 01:05:21 PM »
Hi

Thanks for the tip Marv. I cover everything when I'm finished and my rear garden is not overlooked and cannot be accessed from the street. The only way in is through the house.

Cheers

Rich

Offline Firebird

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Re: A portable steam engine
« Reply #20 on: August 25, 2012, 09:55:43 PM »
Hi

Well it seems ages since I got anything done and posted my progress but holidays and domestic duties come first so I'm told ::)

The valve chest I made from 1/2" thick brass to the same sort of dimensions to the one I made for my beam engine, which runs ok. I figured I must be on the right track. However, I have been talking to Sandy C and it appears all is not quite right. Although the engine would probably run ok its power and efficiency would be reduced if I built it the way I planned. I worked on the drawings with the help of Sandy and redesigned to the best of my ability but it still wasn't quite right. Sandy suggested that I make a new valve chest, thicker, to accomodate a larger slide valve but i was reluctant to start again. The stud holes were drilled in the cylinder using the valve chest as a guide. I doubted I could get the hole pattern exactly right in a new valve chest and get it to fit as well as the existing one. With all that in mind Sandy has come up with a new design that uses the existing valve chest. It means the slide valve is a little more complicated than my design and needs some careful machining but if I get it right the engine will benefit greatly.

Anyway heres todays efforts. I started with the buckle. A piece of 1/4" thick brass is secured in the mill vice and has the end and front edge squared up. A 3/8 hole is drilled to remove the bulk of the waste,
.



A 3/32 cutter is then used to square the hole.



A 1/2" is cutter is used to bring the brass to the required thickness then change back to the 3/32 cutter.



Which is used to remove the waste and bring the brass to its required width.



Then part off the buckle.



And machine to size



Drill and ream a 1/8" hole.



Test fit a piece of 1/8" stainless steel rod.



Thats about it for the buckle.

The slide valve is made from 1/2" square brass. I startedby maching the end square then machining both sides to a shoulder.



Then a 1/8" slot is machined along the centre line.



The buckle must be a fairly good but free fit on the slide valve.

Testing the buckle on the slide valve for fit.



Thats about where I am to date. I hope to get the slide valve finished this weekend so will post more as it progresses

Cheers

Rich   
« Last Edit: August 25, 2012, 10:00:29 PM by Firebird »

Offline Bearcar1

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Re: A portable steam engine
« Reply #21 on: August 26, 2012, 01:34:50 AM »
Glad to see that you are still in there pitching Rich, nicely done.  :ThumbsUp:


BC1
Jim

Offline arnoldb

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Re: A portable steam engine
« Reply #22 on: August 26, 2012, 12:20:11 PM »
Good progress Rich  :ThumbsUp:

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline Firebird

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Re: A portable steam engine
« Reply #23 on: August 27, 2012, 07:53:52 PM »
Hi

thanks Jim and Arnold

Progress was being made until I realised that on the drawing Sandy had specified using phospher bronze for the slide valve, an oversight on my part  :Doh: :Doh

Decisions decisions :shrug: should I carry on with the brass slide valve, which would be ok for light occasional use or scrap it and start again. In the end I decided to scrap it and start again.

Some time ago we met a guy at a steam fair who is a marine salvage dealer, non ferrous metals. Amongst the many items that will come in handy one day that I bought were a couple of bolts, around 1" diameter and 4" long of phospher bronze, I paid 50p each for them, a bargain.



First job was to square it off.



Then chop the head off, a useful chunk on its own



Which gave me this/



I machined the end down to the size needed.



In the mill and machine the shoulder.



Then machine across and make to size



A test fit of the buckle



Machine down to size



Cut the 1/8" slot



Turn over in the vise and machine to size



Then machine the steam pocket



After parting off from the parent material it was finished to size. Because I machined the square hole in the buckle with a 3/32" cutter it has radiused corners so the slide vakve must have its corners rounded to suit with a smalll file.



A test fit on a bit of 1/8" stainless steel rod.



The valve rod is turned down to 3/32" on one end and threaded 5BA



After cutting to length the other end is threaded 5BA to accept buckle joint.





The valve chest is mounted in the mill vise and the centre found using a laser centre finder, you can just see the red dot. Then cntre drilled.





Set up in the 4 jaw chuck using a spring loaded cntre and dial gauge



I used card and some steel to protect the faces. Its first drill through with a 3/32" drill right into the domed spigot at the far end. The turned down portion on the valve rod will fit in here and guide the rod. Then the outer hole is drilled and reamed 1/8" Finally I have turned a small recess in the end. I have to make a gland for the valve rod onto which I shall turn a spigot which will hopefully when fitted into therecess will align everything.



A trial assembly. The brass nuts are not tightened against the sides of the buckle but will have 1/2 nuts as well as lock nuts. Steam pressure keeps the slide valve pressed against the port face but will lift off in case there is any water present.



Cheers

Rich 


« Last Edit: August 27, 2012, 08:03:01 PM by Firebird »

Offline zeeprogrammer

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Re: A portable steam engine
« Reply #24 on: August 27, 2012, 10:53:43 PM »
Excellent.
It always amazes me how people put to use different things.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline NickG

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Re: A portable steam engine
« Reply #25 on: August 28, 2012, 01:47:34 PM »
All looks spot on - bet you never find any of those bolts again - bargain!

Nick

Offline Firebird

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Re: A portable steam engine
« Reply #26 on: August 28, 2012, 06:21:20 PM »
Hi

Thanks Carl and Nick

I bet I don't find any again. For once one of things I bought that would come in handy one day certainly did.

Cheers

Rich

Offline Firebird

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Re: A portable steam engine
« Reply #27 on: September 09, 2012, 06:40:54 PM »
Hi

I had to make the slide valve again. If you look closely at this first photo you will see there is a small gap at each end between the slide valve and buckle. Although the engine would probably run ok Sandy advised making a new one to eliminate the play and therefor give the slide valve its full stroke.



The new slide valve with the old one above.



The valve chest needs a gland for the slide valve rod. Because of the reduced wall thickness to the valve chest I have had to make a piece that will be silver soldered on. Starting with some round brass it is faced and turned to size.



Then turned and drilled through 3mm





Drilled 1/4 to depth



This is my set up for depth drilling. A digital calipre mouhted on the tail stock



Then reamed 1/8 and parted off



The gland body and gland



Make up a mandrel from steel and thread 1/8 x 40



The two parts of the gland are mounted on the mandrel and set up in the mill and drill through tapping size for 7BA.



Then the upper part is drilled clearance size then the body is tapped 7BA



Make 2 studs from 3/32 stainles steel and thread 7BA



A trial assembly



Back on the mandrel both sides are machined down



How it will look on the valve chest



and on the cylinder



With the valve chest cover



Cheers

Rich




Offline zeeprogrammer

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Re: A portable steam engine
« Reply #28 on: September 09, 2012, 07:46:38 PM »
Nice work. I like that valve cover.
The tailstock caliper mount was interesting too. I have to think on that one a bit.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline steamer

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Re: A portable steam engine
« Reply #29 on: September 10, 2012, 01:34:25 AM »
Coming along well Rich!   did you make that press?

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!