Author Topic: Marcher, a twin cylinder marine steam engine  (Read 4244 times)

Offline Moxis

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Marcher, a twin cylinder marine steam engine
« on: August 18, 2018, 08:57:36 AM »
As I promised in the introduce section that I will start a build log of the Marcher engine, so here we are. After I also learned how to add photos here, we are ready to start.

First a few words for background.

A few months ago we decided with two friends to start building models of a half open launch "Lempi", which is a 60 feet long steam powered ship, made on 1879 at the Ahlstrom shipwright in Varkaus Finland. The drawings of the ships made by this company are all digitized, so the original drawings can still be found in Internet.
We downloaded the plans, had them printed in the scale of 1/15, whixh corresponds a model length of about 1200 mm and started working with the hull. I am not going more deeply to hull fabrication, but want to show a special way to cover the hull, because the original ship was made of iron by riveting, and we wanted to show the riveting also at the model hull.
So after the hull was made from wood in a common way by plank on bulkhead method, we covered it with 0,1 mm thick self adhering aluminium foil. where rivetings were made with a tool made from some old toy gear.

On first photos you can see the drawing of Lempi and a hull covered with alufoil.

Because the original ship was powered with a two cylinder compound steam engine, I wanted to have the model made the same way, and this led me to search suitable engines for this project. After many ponderings and calculations I finally selected the Marcher to be the engine for this project, and ordered set of drawings and castings from a UK company Reeves.

Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #1 on: August 18, 2018, 09:16:13 AM »
Hi Moxis,

This will be a fun project/build to follow. The ship's hull that you built looks very nice and your shop looks as clean as an hospital operating room.

Have a great day,
Thomas

Offline Baner

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Re: Marcher, a twin cylinder marine steam engine
« Reply #2 on: August 18, 2018, 09:40:22 AM »
I'll be following.:popcorn:
Is the Marcher going to be close to scale? Looks like it might be. Are you going to do a boiler too?

Dave.

Offline Zephyrin

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Re: Marcher, a twin cylinder marine steam engine
« Reply #3 on: August 18, 2018, 10:27:29 AM »
this hull looks very nice, no visible bruising so easy to occurs with such thin foil !
how did you make the alu foil planking over the curved parts, with joined strips of metal ?

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #4 on: August 18, 2018, 03:57:47 PM »
Thank you all for your kind comments and interest to my build.

# Thomas: Enclosed are a few photos about my machines which I am going to use to make the Marcher. They are a bit bigger than the hobby machines which are normally used for model making, but not "real" power tools which lot of you guys seem to have. However accuracy should be adequate for steam engine building, because it is easy to achieve 0,01 mm accuracy, which I have been using when making for instance gearboxes for my earlier builds. Or what do you people think, how accurate the parts shall be to be able to get a nicely working steam engine?

# Dave: Yes, the size of Marcher is quite near the scale size. However the original engine was a compound, but Marcher`s cylinders have equal bore. I tried to find drawings for a small compound engine but couldn`t find any.  And concerning the boiler, I have not decided yet whether to try to build it by myself or buy one. The problem is that I do not have equipment or skills enough to make rather large silver solderings which are necessary for boiler making. I have asked a few quotations for boilers, but it seems that they are quite pricey, so we will see when the time comes.

# Zephyrin: The hull planking is made using a number of alufoil plates, typically the size 40x90 mm. They overlap each other a few millimeters and are individually cut into the shape using first templates made of paper before cutting the final plate. This work sounds very demanding, but is in reality quite fun and easy, and planking the whole hull didn`t last many days. Because the plates are relatively small, they do not need to bend in two directions. It seems that the quality of this foil is quite soft, making it easy to  follow hull curves.

Offline kvom

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Re: Marcher, a twin cylinder marine steam engine
« Reply #5 on: August 18, 2018, 08:30:05 PM »
Running on steam, you need to be aware that your parts will expand.  So a very precisely fitted assembly can jam tight.  Build it so that it's "half worn out" (at least the parts that will get hot).

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #6 on: August 19, 2018, 08:34:07 AM »
Thanks kvom, that is a good information I have to keep that in mind. So that absolute accuracy is not necessary, good!

About dimensioning.  All the measurements on the drawing are naturally imperial. But we are living in a metric country, and all my tools like drill bits, taps and dies, reamers etc. are metric, so I have to slightly adjust the dimensioning. This means for example that 5BA threads will be made M3, 8BA M2 and so on. I hope this does not bring unsolved difficulties later on. The dimensions of parts can easily be converted into metric, calculator has been invented.

Enclosed are photos of the main drawing of Marcher and castings which are included into the package.


Offline b.lindsey

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Re: Marcher, a twin cylinder marine steam engine
« Reply #7 on: August 19, 2018, 02:09:47 PM »
Shaping up to be a great project Moxis!!  Looking forward to your build of the engine.

Bill

Offline Baner

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Re: Marcher, a twin cylinder marine steam engine
« Reply #8 on: August 19, 2018, 04:01:38 PM »
It's a good idea to check over all the castings with a caliper and make sure they can be machined to drawing dimensions. I can see one of the eccentric strap castings has a piece cut off. There may be other problems. This seems to be fairly common with the older casting suppliers. It's a little unfortunate that the quality doesn't match their prices. I'm sure they'll replace anything that's not as it should be.
Dave.

Offline kvom

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Re: Marcher, a twin cylinder marine steam engine
« Reply #9 on: August 19, 2018, 05:06:51 PM »
I have built a couple of engines with metric plans using imperial fasteners and drill rod.  No reason the same in reverse would be a problem.

Offline Chipswitheverything

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Re: Marcher, a twin cylinder marine steam engine
« Reply #10 on: August 20, 2018, 08:55:08 AM »
Hello Moxis, enjoying your photos and write up, look forward to the build of your engine.    The plated hull looks beautiful, and your nice workshop and machines are enviably pristine!  Hoping to see a few splashes and lines of cutting oil up and along the very clean workshop walls once you machine some of the steel components on the Marcher !   Dave

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #11 on: August 20, 2018, 04:43:15 PM »
Thank you guys for your kind words and interest to my build!

Finally we are so far to start working. I decided to start the build with crankshaft, because I thought it is the most difficult part to fabricate. If I can make a reasonable crankshaft, the rest will be easy  :embarassed:

So I took a 20 mm silver steel bar which was left over from some earlier project and cut a piece a bit longer than what is the length of the crankshaft. My purpose was to make the shaft from one piece in the lathe, because the shaft and big end journals overlap slightly each other, so it is not possible to fabricate it from separate parts.
The positions of big end journals were marked at both ends with an optical centre pop, then the part was centred in the lathe, journals centred in the milling machine, part was attached between the centres  in the lathe, and turning work was started.

After a comprehensive turning session everything was finally made, and I had in my hands a quite acceptable crankshaft.
« Last Edit: August 20, 2018, 04:53:16 PM by Moxis »

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #12 on: August 23, 2018, 01:49:25 PM »
The next item to be made was the baseplate. Very nice casting is provided for this. First some burrs had to be removed with a file, and then the part was attached into milling machine table and milled straight on both sides. The casting was attached into angle plate and holes to be drilled were marked. For the columns M3 threads were made instead of 5BA, and those for the bearing blocks M2 was used.

Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #13 on: August 23, 2018, 02:06:21 PM »
Hello Moxis,
Coming together very nice and a good looking crank.

Have a great day,
Thomas

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #14 on: August 28, 2018, 07:30:14 AM »
Next I was making the columns between cylinder block and baseplate. There is nothing special here, the only important point is to get the columns exactly same height. After a few trials and errors I finally succeeded to do that so that now the columns are equally long within one or two hundreths of a millimeter.
They were made of 5 mm silver steel, and M3 threads were cut at each end. Very handy for this work is a die holder which can be attached into tailstock chuck, and slides forward and back on it`s axle.
« Last Edit: August 28, 2018, 07:33:24 AM by Moxis »

Offline b.lindsey

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Re: Marcher, a twin cylinder marine steam engine
« Reply #15 on: August 28, 2018, 01:47:33 PM »
Lots of nice progress in just a few days Moxis!!  Very nice looking parts too.

Bill

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #16 on: August 28, 2018, 05:32:18 PM »
Thanks Bill. Pensioners have time  ;D

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #17 on: September 02, 2018, 02:36:38 PM »
Next thing to do were the bearing blocks. No castings were provided for these, so they had to be made either of brass or mild steel. I chose brass, because I had very nice 6x40 mm stock material which was just about right for this task.

First suitable 3 pieces were sawn from the stock, they were milled 5,5 mm thick using jig made of suitable pieces of angle iron. With the "jaws" of this jig it is possible to fasten the pieces into milling machine table, because jaws are thinner than the milled material.

Pieces were sawn into two with a slitting saw, soldered then together with soft solder, and holes for bearings drilled in the 4 jaw chuck. Spigots for oil cups were then turned, together with cutting M3 threads for them. And finally 2 mm holes for fastening bolts were drilled.

« Last Edit: September 02, 2018, 02:41:35 PM by Moxis »

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #18 on: September 05, 2018, 02:01:35 PM »
Next thing to do were the oil cups for bearing blocks and bearings itself. There was no drawing about the oil cup on the drawing sheet, but with 4,7 mm diameter and 5 mm height I couldn`t go very much wrong. Oil cups were equipped with M3 threaded studs, through which a 1 mm hole was drilled.

Bearings for crankshaft outer ends were made of OD 8 mm brass stock, turned according to measurements and reamed with 6 mm reamer. With it a nice sliding fit was achieved with crankshaft.
The middle bearing had to be made of two halves, so it was made soldering first two pieces of 6 mm flat brass together, then turned that in the four jaw chuck into measurements, and finally solder was melted to separate the two halves.

3 mm holes were drilled at bearings where the threaded studs of oil cups passed to prevent them from rotating.

Offline Baner

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Re: Marcher, a twin cylinder marine steam engine
« Reply #19 on: September 05, 2018, 02:38:42 PM »
Looking good Moxis. :ThumbsUp: :ThumbsUp:

Dave.

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Re: Marcher, a twin cylinder marine steam engine
« Reply #20 on: September 05, 2018, 06:48:33 PM »
That's a sweet, and rugged, little engine!

Dave
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Damned ijjit!

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #21 on: September 07, 2018, 08:32:22 AM »
Thanks a lot both of you Daves  :cheers: for your interest into my build!

Lessons learned: When I tried to rotate the crankshaft in the bearings, it hardly moved. Even when I tried to fabricate the parts as accurately as possible. So there was no other way than to replace the 3 jaw in the lathe with a collet chuck and start to repair the shaft with very light cuts on the bearing areas with a sharp tool. And finally polish it with 800 grit emery paper. And voila, after a while`s work the crankshaft rotated like a dream.


Offline zeeprogrammer

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Re: Marcher, a twin cylinder marine steam engine
« Reply #22 on: September 07, 2018, 01:55:07 PM »
Congrats!  :ThumbsUp:
Looking like a beauty.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Online Kim

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Re: Marcher, a twin cylinder marine steam engine
« Reply #23 on: September 08, 2018, 01:28:27 AM »
Very pretty looking crank and bearings!  Glad you were able to get them fitted well.

I've always liked the look of these little marine twins!  Enjoying your build.  :popcorn:
Kim

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #24 on: September 09, 2018, 10:14:27 AM »
Thanks zeeprogrammer and Kim! I am very pleased that you like my build.

Next 4 pcs eccentric sheaves were turned of 16 mm mild steel bar. There is nothing special with these turnings but to drill the offset hole. Of course I could have made that in the 4 jaw chuck, but somewhere in Internet I had read that it is possible also in the 3 jaw chuck, to put a packing under one of the jaws. This method was quite new for me, so I decided to try that.
There are at least two formulas to calculate the thickness of the packing:

Simple formula:  Packing = offset x 1,5

More accurate formula:  Packing = 1,5 x offset x (1-(1/8x(offset/bar diameter)))

Calculating after the first formula, I got the thickness for packing 3,49 mm, and after the second one: 3,57 mm.

I selected 3,5 mm to be the compromize for me and made a brass piece of that thickness in the milling machine, put that under one jaw of the 3 jaw chuck and started turning. I think it succeeded quite well, resulting to the wanted offset of near 2,4 mm.

So now the eccentrics are made, but I have no idea, how they must be adjusted to get the timing right. There is nothing shown at the drawing. I wonder if some of you might be able to help me.

« Last Edit: September 09, 2018, 10:19:38 AM by Moxis »

Offline mechman48

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Re: Marcher, a twin cylinder marine steam engine
« Reply #25 on: September 09, 2018, 11:57:19 AM »
Very nice looking engine so far, will be following with interest   :ThumbsUp:

George.
George.

Offline propforward

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Re: Marcher, a twin cylinder marine steam engine
« Reply #26 on: September 09, 2018, 03:07:24 PM »
That is a cunning approach to making the offset hole - thanks for sharing that.
Stuart

Offline K.B.C

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Re: Marcher, a twin cylinder marine steam engine
« Reply #27 on: September 10, 2018, 09:03:33 PM »
Thanks zeeprogrammer and Kim! I am very pleased that you like my build.

Next 4 pcs eccentric sheaves were turned of 16 mm mild steel bar. There is nothing special with these turnings but to drill the offset hole. Of course I could have made that in the 4 jaw chuck, but somewhere in Internet I had read that it is possible also in the 3 jaw chuck, to put a packing under one of the jaws. This method was quite new for me, so I decided to try that.
There are at least two formulas to calculate the thickness of the packing:

Simple formula:  Packing = offset x 1,5

More accurate formula:  Packing = 1,5 x offset x (1-(1/8x(offset/bar diameter)))

Calculating after the first formula, I got the thickness for packing 3,49 mm, and after the second one: 3,57 mm.

I selected 3,5 mm to be the compromize for me and made a brass piece of that thickness in the milling machine, put that under one jaw of the 3 jaw chuck and started turning. I think it succeeded quite well, resulting to the wanted offset of near 2,4 mm.

So now the eccentrics are made, but I have no idea, how they must be adjusted to get the timing right. There is nothing shown at the drawing. I wonder if some of you might be able to help me.


Hi Moxis.

I too have recently machined a set of Marcher castings, it's a fine little engine with plenty of power and like you I came to a stop when timing the engine via the eccentrics.
I made bosses on all of the eccentrics with enough space to fit 1.5mm or 2 mm socket grub screws which allows each cylinder to be timed individually by the age old method of the valve just beginning to open a crack at T.D.C. in the way that you want the engine shaft to turn over, similarly at B.D.C.

There is enough room to make the bosses as if you look at the G.A. you will see that there is a space to allow the reverse gear drag link to clear the upright posts.

I made my engine to fit on a brass bed plate as I wanted it to sit well down in a Launch hull, I include a couple of pics showing the bosses on the main shaft. The pics are not very good but it shows the bosses on the eccentrics, this engine was started by an old friend with very shaky hands and I had to make new parts and buy a new cylinder casting, but all is well now.

Incidentally you have the eccentric fitted wrongly, the flanges should be one to the engine side and the other away from the engine.

I hope this helps George.
« Last Edit: September 10, 2018, 09:07:01 PM by K.B.C »
Your never too old to learn.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #28 on: September 11, 2018, 06:01:51 AM »
Thanks a lot George and Stuart for your kind words and interest to my humble build!

And thanks George for your advice for eccentric adjusting. Somewhere in internet I have read that the eccentrics should be adjusted 90+ degrees ahead of the crank, but nobody seems to know, how much degrees the + should be. I think your approach is the best, to actually see when the inlet ports are opening, and set the bosses there.
I was also considering to make the baseplate from stock material to have it as thin as possible, but somehow I like that cast one with it's rugged outlook to suit better for this machine. It might however be too tall also for me when I will install it into my models hull, but we will see.
And thanks for your pictures, it is nice to see that somebody has really built a Marcher recently.

Offline Zephyrin

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Re: Marcher, a twin cylinder marine steam engine
« Reply #29 on: September 11, 2018, 07:48:42 AM »
Very nice looking parts, beautiful engine for your boat !
the way you have made the eccentrics is very efficient but probably not accurate enough ; the offset determines the travel of the slide valve on the steam ports, hence if it is not exactly as per the drawing, steam distribution will be affected, and maybe you will have to modify in accordance the valve dimensions (or the port sizes and spacing) to keep the performances of the engine at the top.

Offline K.B.C

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Re: Marcher, a twin cylinder marine steam engine
« Reply #30 on: September 11, 2018, 12:22:31 PM »
Moxis

Don't worry about your method of machining the eccentrics with the packer in the 3- jaw.  I made my eccentrics  using the same method  but not so particular as you, there is a 3/32" lift  on the eccentric and I used a piece of steel  as a packer and the engine runs very well and at 30 p.s.i. I can't stall the engine by holding on to the shaft without burning my fingers.

Many years ago a well known academic engineer ( Tubal Cain ) published a formula for doing the packing size method. ( great guy now deceased )
In one of my engine builds ( Stuart D10 ) I was picked up by another older member that I could land in trouble which never occured and I have used this method on several of my engine builds .
To prove a point I used the formula, but can't remember the final dimension and then used my method which proved that mine was about .007" out.
When you consider the amount of points that can effect the lift  i.e. Clearance on the main shaft bearings + clearance of the Sheaves on the eccentrics + the pivot pins on the quadrant + the connection of the valve rod + the clearance on the valve nut and the valve which has to be floating all of this has no effect whatsoever in the running and power output on such a small engine, so it's my opinion that your method and mine  id O.K.

I would point out a few things on the build progression.

When you get to the milling of the steam inlet ports which are shown as 3/64" there is no such thing available as a 3/64" milling cutter so I used  1/16" cutter to no ill effect on the performance, just make sure that the valve covers both inlet ports before marching the valves to size.

Another point to take in is the Valve rod which is threaded 7 b.a. for the valve nut I always make the valve nut with a thro' hole and leave out the threading , put a 2mm socket grub into the nut which saves so much trouble dismantling the reverse gear to adjust the valve ( pic enclosed )

Another point which I am to late to tell you is that I always bore the main shaft at the flywheel end 3/16" dia x 7/16" deep  to allow a coupling to the drive shaft which are usually bored 3/16"

Hope this helps.

George.
Your never too old to learn.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #31 on: September 11, 2018, 05:00:22 PM »
Thanks Zephyrin for your comment. At first I thought I have done something very wrong, but luckily we got an answer from George who has done the same thing with boring the offset in 3 jaw without any problem. It may be that this method is not the most accurate one, but as George reassured us it doesn't matter with this kind of an engine because there are so many other floppies in the mechanism.

Considering milling the steam ports, living in a metric country we have the possibility to get 1 mm milling cutters, with which it is possible to mill those 1,2 mm (3/64") ports. So I will try to make them according to drawing. But being so tiny, there is always a danger to break the cutter, so I have to be very very careful.

And thanks for the idea about the valve nut adjustment. I understand it is much easier to set with a grub screw than with a threaded valve rod. But does it hold it's position and not move when running the engine?

Offline Admiral_dk

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Re: Marcher, a twin cylinder marine steam engine
« Reply #32 on: September 11, 2018, 10:21:20 PM »
Hey Moxie

We have some very nice Titanium Nitride Coated Carbide End Mill from China in 0.8mm, 0.9mm, 1.0mm, 1.1mm and 1.2mm at work.
You can get more sizes all in 0.1mm steps and they are cheap on Aliexpress.

I will have to admit that I have only used them on PCB material and not metal so far - but the glassfiber usually ruins HSS in minutes and these last for many hours.

Best wishes

Per

Offline K.B.C

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Re: Marcher, a twin cylinder marine steam engine
« Reply #33 on: September 11, 2018, 11:26:30 PM »
Hi Moxis.

Your question.

  {And thanks for the idea about the valve nut adjustment. I understand it is much easier to set with a grub screw than with a threaded valve rod. But does it hold it's position and not move when running the engine?}


I have used this method on several engines with no slippage and have never suffered any problems, it sure cuts out the tedious dismantling of the revers linkage. Just make sure that the valve is floating as it's steam pressure that holds it on the face, all that is needed is a little clearance from the bottom of the valve nut.

George.
Your never too old to learn.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #34 on: September 12, 2018, 05:04:42 AM »
Thanks Per, I have also those very small carbide milling cutters intended for pcb work. I have tried them for metal, but unfortunately they are very brittle and break very very easily. From Aliexpress I have bought small milling cutters intended for metal, they last a bit longer, but you have to be very careful also with them.

#George, thanks again for answer. For sure I will use your method when I get to machine those parts.

Offline Zephyrin

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Re: Marcher, a twin cylinder marine steam engine
« Reply #35 on: September 12, 2018, 09:17:45 AM »
It was not my proposal to criticize your work, I actually spend most of my own efforts on the way to get an accurate steam distribution, (or the most precise one can get with these tiny engines !).  I use a valve gear software (the Charlie Dockstader package) to check and adjust rod sizes and pivot positions for the most efficient steam distribution with the oval diagram.

As regard milling the port on the cylinder face, these tiny cutters flexes a lot, and it is difficult to get a straight line. I now use a home shop made mill bit to mill the 3 ports in one shot by "gang milling", once the steam passages are drilled.

Offline Admiral_dk

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Re: Marcher, a twin cylinder marine steam engine
« Reply #36 on: September 12, 2018, 12:30:03 PM »
I run the mill bits at over 25000 RPM's as they should in those sizes, but they do admittedly still flex a bit - running them slower results in more flex ….

In those sizes we should probably use single flute (aka D-Bits) as mills in metal as they usually are much stiffer and true running.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #37 on: September 12, 2018, 06:42:55 PM »
Thanks for the tip Zephyrin to use home made milling cutters. Very effective to get all the ports made at the same time. From which material do you make those cutters?

Admiral_dk, unfortunately the max speed of my milling machine spindle is only 3000 rpm, far from enough. That might be the reason why I have not succeeded very well with those tiny cutters. It might be better to use Zephyrin's way: To use self made milling cutters.

Offline Zephyrin

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Re: Marcher, a twin cylinder marine steam engine
« Reply #38 on: September 12, 2018, 08:21:41 PM »
Cutters are made of carbon steel, silver steel, or 100C6 steel, milled and/or filled or "Dremel-ized", hardened and tempered. Teeth are lightly sharpened with a stone before use.
The point is that the stem must long enough to reach the centre of the cylinder face, and without flexing...
The external dimensions of the cutter are easy to measure, corrected with grindstone on a dremel if required, and therefore, the ports are precisely cut, with sharp edges.
 I learned this method while reading the paper of JP Bertinat in the "Model Engineer" ,on Marcher precisely,  ages ago...


Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #39 on: September 13, 2018, 06:00:12 AM »
Very clever indeed Zephyrin! I might try that too. I wonder if you have still that article.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #40 on: September 14, 2018, 07:10:38 AM »
Slowly progressing. This time working with cylinder block. It was first milled into outer dimensions. Then marked the ports, holes for columns and cylinder centers. Holes for columns drilled. And finally attached on the columns with M3 model nuts. Next I have to consider, should I bore the cylinders in the lathe using faceplate, or in the milling machine, using boring head. What would you suggest?

Offline Zephyrin

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Re: Marcher, a twin cylinder marine steam engine
« Reply #41 on: September 14, 2018, 08:47:42 AM »
As long as the bores are truly perpendicular with the bottom face, it depends on the confidence you have with your machine tools; on the lathe you may give a shaving of the bottom face for the cylinder cover on the same setting used for the bore. milling marks with bronze can be annoying.

PS I send you a PM with the link for the Marcher article...

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #42 on: September 14, 2018, 02:35:22 PM »
Good point Zephyrin. I am not quite sure if the spindle of my milling machine is absolutely perpendicular to the table. So in the lathe it will be.

But first big enough holes must be drilled to get the boring bar into the hole, and to fasten the block easier to the faceplate. So in the first photo I am boring the cylinders roughly, and in the second one light shavings are taken in the lathe with a boring bar.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #43 on: September 16, 2018, 04:35:55 PM »
Cylinder covers were made next. There are 4 pcs nice castings provided, two for top and two below the cylinder block. Simple turning work, but you have to think in which order to turn them.

After everything has been turned, the piece is fastened into rotating table and four holes for M2 screws were drilled. And finally holes for the screws were marked on cylinder block, using cylinder cover to locate them, then drilled with 1,7 mm drill bit and M2 threads were cut.

Offline K.B.C

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Re: Marcher, a twin cylinder marine steam engine
« Reply #44 on: September 16, 2018, 07:14:03 PM »
Hi Moxis,
Your workmanship and finish is to be admired, it's when I see the finishes that most of you guys produce makes me try harder to get a better finish to mine.

Well done .
George.
Your never too old to learn.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #45 on: September 17, 2018, 06:44:42 AM »
Thank you very much George for your kind words. I always try to make my parts as accurately as possible according to dimensions and also visually appealing. Sometimes it works, sometimes it doesn't. One thing that got me building the Marcher is the outlook of the cast parts, which gives the engine the look of a real old steam engine; rather than only fabricate everything from stock materials.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #46 on: September 23, 2018, 12:07:37 PM »
Cylinder covers underneath cylinder block were made next. Normal turning work at the lathe. Internal threads for piston rod glands were made with M6x0,75 tap. After that the glands for piston rods were turned of 10 mm brass rod. M6x0,75 threads were made with a die holder held at tailstock chuck. Threads were made by rotating manually the lathe spindle.
After that the workpiece was moved into a collet held in rotary table, and 6 pcs 1,6 mm horizontal holes drilled into piston rod glands.
« Last Edit: September 23, 2018, 12:13:00 PM by Moxis »

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #47 on: September 27, 2018, 08:27:25 AM »
Making the trunk guides was the next task. Casting including both guides is provided for these.  Again a little while was necessary to think in which order the parts must be turned, because on the other end of the guide there is only a narrow flange without possibility to grip it into the lathe chuck.

So the only possibility was to turn both ends of the casting into final measurements and only then part them off of each other. Then face the narrow flange into final thickness, bore the hole, and voila, we are almost there.

The only thing that remained was to take the parts into milling machine and mill the slots on both sides of the guide, drill the holes for fastening screws (M2), and the parts were ready for installing.
« Last Edit: September 27, 2018, 08:33:15 AM by Moxis »

Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #48 on: September 27, 2018, 08:32:15 AM »
Hello Moxis,

Coming along real well.

Have a great day,
Thomas

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #49 on: October 03, 2018, 03:18:28 PM »
Thank you Thomas for your kind words and interest to my build. It is always nice to get comments from you guys, it increases a lot motivation to work forward.

This time I will show a small update, how I was making the connecting rods. This was rather complicated task with some quite accurate machining to get everything straight and running freely.

There was one gunmetal casting provided for both big end bearings. This was first faced and milled into final dimensions. Holes for halves of bearing screws (M2) were drilled, the upper part sawn away with 1 mm thick slitting saw, and threads made to the lower part. I make always internal threads so that after drilling the hole, I attach the tap into drilling chuck, and without moving the table, start the thread my rotating manually the chuck. After a couple of revolutions I withdraw the chuck and install the winding iron (not sure about name of this tool) and complete the thread manually. This ensures that the thread is absolutely straight.

After making the threads, the two halves of the bearing were attached into lathe 4 jaw chuck, and hole for camshaft was drilled & reamed. Connecting rod itself was turned of mild steel and attached into bearing block with M2 screw & epoxy glue. The unit was then turned into shape, upper end drilled and brass bush inserted there. Finally the flats for upper end were milled and the whole unit cleaned with 400 grit emery paper.
« Last Edit: October 03, 2018, 03:22:13 PM by Moxis »

Offline Admiral_dk

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Re: Marcher, a twin cylinder marine steam engine
« Reply #50 on: October 03, 2018, 10:18:34 PM »
It really starts to look like a engine that could run (I can see what is missing) - nice finish  :ThumbsUp:

 :popcorn:

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #51 on: October 10, 2018, 03:11:42 PM »
Thanks Admiral_dk, I really hope that you are right. The worst thing that could happen is, when you try to start the engine it doesn`t run and you notice that you have done something fundamentally wrong.

Well let`s not think that yet. This time I made the piston, piston rod and crosshead. No casting was provided for these, so they had to be made of stock material. I had a piece of 12 mm brass rod available, so the parts were turned very fast. The only thing which I made differently from plan was the connecting pin for the cross head. Instead of a slot screw, I wanted it to be operated with allen key, so it was made of 3 mm silver steel which was first bored with 1,7 mm, M2 thread cut into it, and finally a M2 grub screw attached at the other end, and a M2 normal screw to the other. These were fixed then with epoxy.

Installing these parts together was quite accurate work, parts had to be sanded carefully here and there to get them moving freely. Finally that succeeded, and next task can be started.


Offline K.B.C

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Re: Marcher, a twin cylinder marine steam engine
« Reply #52 on: October 10, 2018, 09:10:12 PM »
Hi Moxis,

It's a good idea in one way to fit Cross Head pins with Hex for M2 grub screws but not so good in another way.

If you have the M2 grubs it will be difficult if you have to undo them after the reverse gear has been fitted and the engine timed, as the key will not be long enough to get thro' all of the levers.
If they are slotted a small screw driver can get thro' with ought dismantling the gear which is a bit of a pain as the engine will need to be timed again, otherwise you are making an excellent little engine.

I mentioned some time ago that you should bore the end of the shaft at the flywheel end 3'16" x 7/16" deep to fit a 3/16" dia shaft to take a coupling, as I have done on my Marcher.

Hope this helps.

George.
Your never too old to learn.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #53 on: October 11, 2018, 07:25:24 AM »
Good point George, that I didn't think when making those pins. I have to consider this again.
Could you show a picture about your coupling at the flywheel end, I didn't quite understand the idea.

Offline K.B.C

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Re: Marcher, a twin cylinder marine steam engine
« Reply #54 on: October 11, 2018, 12:28:47 PM »
Good point George, that I didn't think when making those pins. I have to consider this again.
Could you show a picture about your coupling at the flywheel end, I didn't quite understand the idea.

Moxis.

Pic of the shaft end shows the 3/16" dia x 7/16" deep bored hole, this allows you to fit in a piece of 3/16" dia rod ( glue in with Loctite 603 , the green stuff) and then a universal coupling can be fitted.
If not you need to fit drive pins at 180 deg on the end of the flywheel to pic up holes in a disc fitted to the prop shaft.
I make all of my own couplings with the old fashioned ball and pin screwed to take a prop shaft with a lock nut on it.

Video of Marcher engine on air at 10 p.s.i. 
note that the engine runs well without flywheel.

George.
Your never too old to learn.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #55 on: October 11, 2018, 12:51:27 PM »
Thanks for the video and photos George, now I understand the idea. I have to follow that and build the ball/pin coupling you suggested.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #56 on: October 11, 2018, 04:18:30 PM »
Small update: Today I finally dared to start making the steam ports. After careful marking 1,2 mm holes were drilled first at each end of the narrow inlet ports and 2,4 mm at the outlet port. There was no dimension for the depth of the ports in the drawing, but roughly calculated the narrow ports were 3,5 mm and the outlet port 7,5 mm deep.
Inlet ports were then milled very carefully using a dia 1 mm cutter, taking only 0,5 mm at each run. A 2 mm cutter was used for the outlet ports.

And for my great surprise everything went well and now I have quite useful steam ports on my cylinder block (I hope).

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #57 on: October 13, 2018, 01:17:00 PM »
Very careful drilling was necessary to make the steam passages  to cylinders. Angle and depth had to be exactly right for not to drill into wrong port. Drawing didn`t give any diameter for the drill, but 2,2 mm seemed to be about right.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #58 on: November 01, 2018, 09:22:09 AM »
Thank you all who have followed my blog and have interest towards it. There has been quite a long time after the last update. This is due to other engagements and also some faults I made during machining of slide valve chest castings, but now everything is solved and I can continue.

So the next item was to fabricate the slide valve chests, covers & slide valves with all very tiny parts involved. Slide valve chests are supplied as a paired casting. This was first milled at final thickness. The two valve chests were then separated from each other using slitting saw, and outer sides milled into final dimensions. Holes for valve rods were drilled  and the upper holes tapped M5x0,5. Oval flanges for valve rod glands were milled using rotary table.
Covers for valve chests were turned in 4jaw chuck and holes for M2 studs drilled. Valve rods were turned of 2,5 mm stainless steel and M2 threads cut at the lower ends.

The valves themselves were machined of  pieces of brass, but insted of cutting threads to the valve rods for their adjustment, I used method suggested by some of you by using M2 grub screws to lock the slides to the rods. I am sure this makes final timing much easier than to use the method suggested at the drawing.

A lot of milling work was involved into these items, and I am glad this is done and I can concentrate myself into next items.
« Last Edit: November 01, 2018, 09:32:04 AM by Moxis »

Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #59 on: November 01, 2018, 09:27:52 AM »
Hello Moxis,

Your project is looking real good.

Have a great day,
Thomas

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #60 on: November 01, 2018, 09:36:06 AM »
Thank you Thomas, that was a really fast reply. I hardly had my update finished when I noticed your reply.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #61 on: November 15, 2018, 07:49:35 AM »
Next update includes fabrication of eccentric straps with rods and the expansion links.

A common casting strip for all 4 eccentric straps is provided. First it was milled into correct thickness. After that all the straps were separated from each other with a slitting saw. Holes for connecting bolts were drilled, and the straps were divided into upper and lower parts again with slitting saw.

It was very difficult to find a correct datum for boring the holes for eccentric sheaves, and finally I decided to use pieces of self adhering paper where centrum lines were drawn to show this. Straps were attached into 4 jaw chuck and centred as accurately as possible, and boring made.

Eccentric rods were turned conical using 3 mm silver steel rod, M2 threads cut at both ends, and rods installed into straps with threads & epoxy glue.

Expansion links were made using 3 mm mild steel. First I thought to machine them in the milling machine using rotary table, but finally decided to saw them out using jeweler`s saw. Quite slow process and many broken saw blades, but finally also this task was completed.

Offline Jo

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Re: Marcher, a twin cylinder marine steam engine
« Reply #62 on: November 15, 2018, 09:03:35 AM »
It was very difficult to find a correct datum for boring the holes for eccentric sheaves, and finally I decided to use pieces of self adhering paper where centrum lines were drawn to show this.

Yes it is very difficult to line up in the centre of the hole  :Doh: I like your use of the paper to fill it in.

I was trying to remember what I did on the Triple orphans I recalled there was zillions of straps to do  :facepalm: .. then I found a pic of using a stencil to draw on a circle so that I could see if the hole looked right, then checking again after I had got the centre hole round.

Jo
Usus est optimum magister

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #63 on: November 16, 2018, 08:04:17 AM »
Thanks Jo, that could have been also a very good method to find the right position to bore the hole.

Next a short update. Because I do not own a watchmaker`s lathe to make small screws, I had to find another way to fabricate the eccentric rod pins. First I tried to make them from 3 mm silver steel, but that didn`t work.  The needed thread is M2, and diameter of the cylindrical part is 2,5 mm, and then I should make the hexagonal bolt head, not possible with my skills and relatively big lathe.

After thinking hard to find a solution for this, I finally took a 12 mm long M2 bolt, screwed on it 5 pcs M2 nuts and attached that into 3 jaw lathe chuck. Then I turned the nuts into round 2,5 diameter nuts, and screwed those on another, shorter M2 bolt with hexagonal head. And finally secured those round nuts on the bolt with tiny drop of epoxy. And voila, I had the necessary threaded pins for eccentric rods. I have never seen anybody make the threaded pins like this, so this is why I publish this method. It might help some of you with equal problem.

Offline Jasonb

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Re: Marcher, a twin cylinder marine steam engine
« Reply #64 on: November 16, 2018, 08:53:58 AM »
The other option for those pins is to drill and tap the end M2 and screw in a bit of threaded stock, you get a thread all the way upto the shoulder. make the rest from hex stock if you have it or use larger round and hill the hex after turning the 2.5mm dia section.

Other option for the straps is to hot glue or superglue a bit of thin metal sheet to the face then you can scribe and punch the ctr position and use a spring ctr and dti to clock it in which is more accurate then a cross on a bit of paper or tape

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #65 on: November 16, 2018, 09:23:13 AM »
Thanks Jason for your comments. I agree that there must be several ways to make these pins, and I am sure that you more experienced guys have much better solutions for this. But because I am relatively new to the hobby and do not have long experience about machining, I have to find easy enough ways to do things.

And I am quite sure that your method of scribing and clocking the center for eccentric straps is way better than my humble method. But when making my first steam engine I have to find simple ways to make things and learn and learn again from you more experienced guys.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #66 on: November 23, 2018, 06:00:11 AM »
A little bit filing sanding and polishing here and there, and finally the engine rotates and all parts are moving nicely.  I hope anyway that there is not too much slop in all the various joints to prevent easy running of the machine.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #67 on: December 11, 2018, 10:32:28 AM »
The only thing that is still missing is the flywheel and plumbing. First I started to work with plumbing. That was rather easy, first I made the screw joints using
 fine metric threads with M5x0,5 tap and die. Those were silver soldered with parts of OD 4 mm copper tube. And very soon both inlet & outlet tubing was made.

The last thing was to turn the flywheel using gm casting provided for this. Nothing special with this too, and finally I had my first steam engine at least mechanically ready.

I inserted graphited yarn into the grooves of pistons & packings of piston and valve rods. This made the engine a bit difficult to rotate manually, but I hope it will still be able to run with compressed air, and later with steam, if we are very lucky.

I adjusted the timing so that valve eccentrics are about 100 degrees ahead of cranks, I really hope that this is enough so that there is no need to adjust them further.

Offline Admiral_dk

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Re: Marcher, a twin cylinder marine steam engine
« Reply #68 on: December 11, 2018, 11:49:46 AM »
It's a beauty  :praise2:

Are you planning on painting it leave it as is ?

Looking forward to see it run.

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #69 on: December 11, 2018, 11:59:11 AM »
Thanks Admiral_dk!  First I thought to paint the unmachined surfaces of castings, but now I have changed my mind. So I will leave it as is.
I am also waiting with interest the first testing, what happens when compressed air is connected....

Offline gbritnell

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Re: Marcher, a twin cylinder marine steam engine
« Reply #70 on: December 11, 2018, 12:11:49 PM »
Some engines need a coat of paint while others like yours are beautiful in natural metal.  Very nice work!
gbritnell
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Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #71 on: December 11, 2018, 01:12:50 PM »
Hello Moxis,

Boy what a beauty, looking forward to a video of it running.

Have a great day,
Thomas

Offline b.lindsey

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Re: Marcher, a twin cylinder marine steam engine
« Reply #72 on: December 11, 2018, 01:42:29 PM »
This one definitely calls out to be left natural in my opinion Moxis. Beautiful result and looking forward to seeing it run !!

Bill

Online Kim

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Re: Marcher, a twin cylinder marine steam engine
« Reply #73 on: December 11, 2018, 04:39:47 PM »
Really nice looking twin, Moxis!  I agree with your assessment - as everyone has been saying, it doesn't need a coat of paint!
Kim