Author Topic: Twin Cylinder Steam Engine (Read 97495 times)

Darren · « **on:** April 07, 2009, 02:45:48 PM »

Right I admit it you got to me and I've decided to build an engine.

I got taken by this one, not too complicated by the look of it. http://www.john-tom.com/MyPlans/Steam%20Engines/RotaryValveEngine.pdf

I got started tonight on the crankshaft, but I came across a problem, I need a V Block with a clamp so I can accurately mark both ends of my crank. It was going well too till I realised marking one end was simply not enough, so I got" well stuck" !!

No point showing the pic's cos I'll have to do it again.

So for the V Block I've found this one, not knowing much about these things I thought I'd better ask about it on here and see if it's the right thing or if i should be looking for something better? http://www.rdgtools.co.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww.rdgtools.co.uk%2f&WD=blocks&PN=VEE_BLOCKS.html%23a08309BIG#a08309BIG

Half way down the page at £16 or so....

Oh, and while we are at it what else may I be needing? Reamers I guess?

sbwhart · « **Reply #1 on:** April 07, 2009, 02:56:29 PM »

Darren

Just ran a copy of the plans off:- you don't need to turn the crank from solid the easy way to make a crank shaft is to fabricate one up. John did a superb right up on building a symilar engine on HMEN he's got it on disc he will I'm sure fix you up with a copy. It shows how to fabricate a crank.

Stew

Darren · « **Reply #2 on:** April 07, 2009, 03:00:21 PM »

Lathe Dog and live center?

I'd like to try to make this on the mini lathe, if I take the chuck off and use a center, the chuck backplate (part of the spindle on this lathe) can drive a dog.

Well that's what I have in mind, advice always welcome of course.

Darren · « **Reply #3 on:** April 07, 2009, 03:03:45 PM »

Well that just takes all the fun out of it Stew, haven't you noticed that I'm a glutton for punishment

Seriously, I'd better wait for John before ordering anything, Thanks for the heads up

Darren · « **Reply #4 on:** April 07, 2009, 03:46:49 PM »

I found this http://www.homemodelenginemachinist.com/index.php?topic=862.0

Is that what you were referring to Stew?

Interesting,

John, do you make your steam engine cranks in the same way?

sbwhart · « **Reply #5 on:** April 07, 2009, 04:10:48 PM »

Yes thats the sort of thing.

I know what you mean about the chalenge of making a crank from solid, I've never tried to make one from solid but one day I just might give it a go.

Stew

bogstandard · « **Reply #6 on:** April 07, 2009, 05:18:10 PM »

I'm here, eventually.

Darren, building your first engine is a state of mind. Some people start on say a loco, spend 10 or 15 years building it to perfection, then give up model engineering altogether. They started a major project, kept at it until the end, then just burnt themselves out. If they had taken time out, like Stew has done, to do a few more basic projects, then they would most probably still be making engines.

I am a firm believer at starting at the bottom, and work your way up. Doing it that way, your tooling costs remain smaller and you are not stretching yourself to the limits of your experience, you learn your techniques first, then start to climb the stairs.

I did a guide with step by step instructions, where a complete beginner could start off with the basic tooling plus a little turning and milling knowledge, and by gaining simple techniques along the way, end up with one of these, or one very similar, depending how far you want to go.

There is a member called Shred on HMEM who is doing the build at the moment.

http://www.homemodelenginemachinist.com/index.php?topic=4294.0

My composite method of building cranks starts here, on the post about building this engine.

http://www.paddleducks.co.uk/smf/index.php?topic=2872.msg12371#msg12371

So YES, you can build a fairly complex engine to begin with, just like the one you are contemplating.

Forget about reamers and things at the moment, you can get yourself tied in knots and spend a lot of money and get nowhere very fast.
If you can bore to good tolerances, you shouldn't need reamers at this early stage.

Although it is against your wish, the first thing I personally think you should do is the most basic of oscillators (wobbler). That should only take a couple of days at most, but seeing it running, the first engine you ever made, will really give you the buzz to go deeper into it. By taking on a complicated build as the first one puts you into a bad frame of mind if you hit problems, or it doesn't run.

Maybe try #25 from the planset first. Fairly easy to make and looks good when finished.

http://www.john-tom.com/ElmersEngines/25_26_Wobbler&Boiler.pdf

Then progress onto the one you really want to do.

John

Darren · « **Reply #7 on:** April 07, 2009, 05:51:03 PM »

Don't worry about me running out of puff John, I've got plenty of projects to pick up and put down. I also have patience, my bike took me four years to build. Not much was left original and that includes the engine internals. There wasn't a single nut left unturned.

I'd have carried on if some bugger hadn't swiped it.

But most of all, if it ain't a challenge, I ain't interested, just the way I am.

You should see my house, now that was/is a challenge....on going story.....

Lot's to read on your posts, getting through them slowly.
You get everywhere...!! I'm glad to say....

Right, gotta go back and do some more reading of some very talented chaps engines over on Paddleducks

bogstandard · « **Reply #8 on:** April 07, 2009, 06:17:25 PM »

Darren,

I do understand where you are coming from, and of course the choice is yours and yours alone. I can only make suggestions.

If you want the whole lot set up as a little book, I have it on disc, or if you want to download it, here are the links. It makes it much easier to read and understand. Even if you don't build it, the book is full of all sorts of hints and tips to do things if you don't have the 'correct' equipment.

http://www.rake60.com/photogallery/Piston_Valve_Engine_01.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_02.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_03.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_04.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_05.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_06.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_07.pdf
http://www.rake60.com/photogallery/Piston_Valve_Engine_08.pdf

Rick (Rake 60) very kindly hosted it on his own site.

It only takes a few minutes to download if you are on broadband.
Save it from the PDF file to your computer. If printed out it makes up into a complete book of about 110 pages+

BTW, if building from Elmers plans, they are geared up for the US market, so you will most probably have to convert either to UK imperial (B.A) or metric.

John

Darren · « **Reply #9 on:** April 07, 2009, 08:24:04 PM »

Thanks John,

I will download those and print them off for some bedtime reading

I already have a couple of reamers for the bores, nice and sharp too. I used them to ream the bronze bearings I made for the turntables.
About half inch, 31/64 if I remember rightly. One is still unused. Which just happens to be the size of the plans I linked earlier.

I'm umming and aring of course, but I will settle to a rhythm soon enough and get going.

Just an idea or two, I could use slate for the block and line it with some PB1 I have, or steel. It would be different, but would it be wrong? I dunno, can't make my mind up.
Could also use it for the base. It lathes, mills and drills ok.

I mean, it's not as if it's hard to find around here.....

Cuts easily into blocks with diamond tooling.

sbwhart · « **Reply #10 on:** April 08, 2009, 01:09:47 AM »

Hi Chaps

I'm thinking of making one of those little Bogstandard engines, but first I want to do some more on my loco, I'm setting myself the objective of getting it running on air, but who knows I may change my mind

Stew

bogstandard · « **Reply #11 on:** April 08, 2009, 02:20:32 AM »

Darren,

Never having had much call for slate based engines, I can only give maybe a rough guesstimate as to the problems you would encounter.

I wouldn't ever run it on steam, compressed air only.

You could sleeve the cylinder with something like K&S brass tube epoxied into position. That would save you a boring operation.
I suspect slate has a fairly good carbon content, so should have good bearing properties, including face to face, maybe as a bore as well??

Fairly small screws are usually used in model engines, that might cause problems, I have no idea how strong a small thread would be in slate. Maybe threaded inserts or helicoils would overcome the problem.

Maybe the way to proceed is to do a few trials and see what it throws up.

I will be going thru the same sort of trials a little later on, I am going to see how I get on with perspex. I also have mountains of the stuff.

John

sbwhart · « **Reply #12 on:** April 08, 2009, 03:09:02 AM »

Slate engine now that interesting

slates very brittle more so than cast iron, but its good in compression it certainly posses an interesting set of chalenges

They sell figurenes down your way in the gift shops, made from powdered slate bonded in epoxy that would be another option, if you could get a big enough figure you may be able to machine a block out of it to make the cylinder.

For fixing the small screws how about drilling a parrallel hole into the slate, filling it with epoxy or something symilar and drilling and tapping into it.

Her's a question for John:- with the rotating valve engine how would you reverse it ?. change direction of air flow or can you change the valve linkage ?

Stew

bogstandard · « **Reply #13 on:** April 08, 2009, 04:10:54 AM »

Stew,

Never having built one, but a quick look at the plan, the engine as is, can only rotate in one direction.

I suppose you could play about with the valve linkage by swinging it into a different position might enable it to run in reverse, but I suspect it would be doubtful, as the porting is cut to match the direction of engine running, and just might not run in reverse.

I have made a crankshaft rotary ported engine and that worked OK by swapping the inlet and exhaust over. I don't think it would work with this engine because of the direction specific porting.

Maybe a combination of the two could be used to get it to run.

John

sbwhart · « **Reply #14 on:** April 08, 2009, 04:17:00 AM »

Thanks for that John I was looking at the drawings last night trying to work out

if it could be reversed, came to the conclusion it would be dificult following the as drawn plans.

Cheers

Stew

Darren · « **Reply #15 on:** April 08, 2009, 06:12:05 AM »

Hi Guys, I did consider that and also came to the conclusion that it would be difficult with that design.
Saying that it looks simple, but I would imagine a new head etc could be made later if desired with reverse facilities?

I don't this slate would have a problem with steam, but threading it would be a problem. Probably bonded threaded sleeves or the bolts would have to go right through.
Bonding to it is a simple matter, I have plenty of the correct adhesive, enough to last all of us our lifetimes !!! It's an epoxy based compound that I guess could also be threaded once it has hardened. It was only a thought, I prob won't use it as it adds too many complications at this/my early stage.

Bernd · « **Reply #16 on:** April 08, 2009, 04:50:38 PM »

Hey Darren, if you do down load Bogs engine you'll find it a very entertaining read. He has a very good sense of humor in his write up. See if you can find them.

I got the biggest kick out of finding one of the humorus things Bogs put in one of the pics.

Bernd

bogstandard · « **Reply #17 on:** April 08, 2009, 05:13:47 PM »

Very few people have found that one Bernd.

Bogs

Darren · « **Reply #18 on:** April 08, 2009, 05:35:07 PM »

Well I've made a start, Four little 5mm thick SS discs with a 4.5mm hole in the middle. I'll drill or bore them out to 5mm when the Silver Steel ordered arrives.

I might even make a tiny boring bar from the Silver Steel rod......but I'll have to do some reading first.

Bernd · « **Reply #19 on:** April 08, 2009, 07:07:35 PM »

Quote from: bogstandard on April 08, 2009, 05:13:47 PM

Very few people have found that one Bernd.

Bogs

If you only knew how I giggled like a little kid over that one.

I even had to show the wife. She even got a chuckle out of it.

Bernd

bogstandard · « **Reply #20 on:** April 08, 2009, 07:38:45 PM »

Darren,

How did the little lathe cope? Any better than before?

Bernd,

What is life without a bit of humour now and then. Especially when you can slip it in without being noticed.

Bogs

Darren · « **Reply #21 on:** April 08, 2009, 07:52:08 PM »

Hi John, still not done much with it, these parts are very short...

But, I have to say it feels very smooth, even the crosslide which I know you didn't do much with. I will be making more use of it as this project goes on and will report back.
It is showing me how worn my crosslide screw is on the bigger lathe. I must finish that project sometime.

As these parts are 30mm dia SS I did do most of the work on the bigger lathe. Mainly because parting was going to be a pig, and it was. I don't think the little lathe would have coped.

But I did face and true the thickness of the discs on the mini, Could have done it on the larger lathe with collets and stops, but I didn't. For this the little un coped just fine.
Oh, btw the carrage lock was real handy, that worked a treat

I have found a nice piece of slate to bolt it down to as well. That should help....

Darren · « **Reply #22 on:** April 08, 2009, 07:55:48 PM »

Bogs, I bin readin your book and you linked this place

http://www.jjjtrain.com/vms/library.html

Now that will keep me out of trouble for days,

I'm trying to read your build but now I'm distracted....

Darren · « **Reply #23 on:** April 08, 2009, 09:14:56 PM »

Bogs, quick Q..

When you use metric threads in small sizes do you use coarse or fine pitches?

bogstandard · « **Reply #24 on:** April 08, 2009, 09:31:59 PM »

Darren,

If you read the posts on here you will find I have already made it known

http://madmodder.net/index.php?topic=535.0

plus another one, very recently

http://madmodder.net/index.php?topic=944.0

You will find that 99.999% of metric threads used are the coarse variety. Metric fine are few and far between. In fact I only own one metric fine tap, 4.5mm, and that is for cutting threads in the bottom of Ronson cigarette lighters for fitting the filling valve.

Bogs

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Author Topic: Twin Cylinder Steam Engine (Read 97495 times)

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