Simple Mill Engine - Stewart Hart ME.4460 - Part CP11

Hi

I have just started making this little engine and can not find anything about this part mentioned except in Fig 3

I take it that this is just a cap and is glued in place using Loctite.

Would it also benefit from a small hole to avoid compression issues at the top of the valve piston?

Thanks for an awesome project

Regards

Bruce Edney

Hi Bruce

Yes its just a simple cap a tight fit and fixed with supper glue, in fact the engine will work perfectly without it, its just their to tidy things up.

It doesn't need a vent hole the exhaust port does that job.

Thanks for you interest in the engine, there have been quite a lot made, the design is very robust to the odd mistake and is ideal for a beginner.

Cheers

Stew

Edited By Stewart Hart on 24/01/2015 08:04:14

Thanks Stew

Hi Stew

I have another question. I know the dimensions are not critical but just trying to get it looking right.

In the photos and the drawing of the base it shows a significant amount of material at the crankshaft end however the measurements don't stack up.

Should the overall base length actually be about 250-260mm?

Cheers

Bruce

PS. I have had the engine running and after fixing a few engineering issues (engineer not design) it runs like a dream.

Edited By Bruce Edney on 16/03/2015 07:29:56

The 4 mounting holes should be 225mm ctrs and the overall length 240mm

Check your messages

Edited By JasonB on 16/03/2015 08:04:11

Hi Bruce

Pleased to her you've got the engine running.

I've measured up the base of my engine, as you have guessed I didn't follow my own drawings , I actually shaped the end of the base to make it look more like a casting, the actual size of my base is 205*50 and the wooden brick work is 215*55, with the mounting holes 198*39

You can see this in these photos.

Sorry if I've confused the issue, but I sometimes don't actually publish what I have made as I try to and correct/simplify things that I've found out in the process.

Cheers

Stew

Hi hope this is the correct thread for this, couple of photos of my attempt to construct this engine, I have never used a lathe from leaving school and I plan on retiring in two years so you can work out the sums.

This is the start of my further education, the engine is still to be completed and is in rough stages, the threaded bar to be cut to correct length, washers added.

May not be to the same high standard I see on this forum, but I am pleasantly please with me efforts, when I get it completed and running I will then spend time making it look good

Best thing about it is, I have had a great time leaning new skills.

Just thought I would share

Looks good from over here

Neil

Looks very good from her

Nice work Jim

Its always great to see one of these engines being made by a beginner, as it was designed as a beginners engine, there must have been quite a lot made by now.

Can't wait to see a picture of the finished engine or even a video of it running

Cheers

Stew

I'm building my second example at the moment. The engine works, is reasonably tolerant of mistakes, and has some interesting challenges without being baffling. I enjoyed making the first one.

This time it's a beginner+ project in that I'm being much more fussy about finish and building to plan. The idea is to compare the two builds to see where I've improved, and - more important - identify which skills still need attention. Judging by the reject rate, I have a long way to go!

I'm experimenting with another approach to construction too. First time, I made the parts one at a time, each starting as a lump of metal and only downing tools when the part was complete. Second time round I'm making several parts in parallel and not necessarily finishing all machining before moving on to another part. The disadvantage of the first method was making mistakes because I got bored, The disadvantage of the second method is I make mistakes because I misremember what needs doing next. It appears I'm better at making mistakes than engines!

Dave

Dave The man who didn't make mistakes, didn't make anything. Also experience is built on mountains of scrap

Roy

Just thought I would update, slow but getting there

That's looking very tidy Jim. Do she run yet?

Jim

Not yet still got eccentric to fit. The flywheel does turn the crank around and everything does what it should do but feel unit is tight, think I will need to tweak it a bit to get smooth movement but plan to do that when everything is fitted, hope to get some workshop time tomorrow

Jim

Hi Duffer

Sorry I missed your post on 30/10/17 I was on holiday at the time and got behind with following the forum.

Your build is looking good, have you got her running ?.

Stew

Hi Jim

That,s looking good too, best way to shake out the tight spots is to loosen all the screws, then tighten them up one by one any screw that causes it to bind needs investigating and the cause fixing.

Look forward to seeing the completed engines and a video if posible

Cheers

Stew

Stewart, on the brass bands around the wooden lagging strips on the cylinder, are those brass rivets' holes drilled into the metal cylinder, or are they just into the wood?

Also, where's a good place to buy the graphite packing for the piston ring and glands?

Yes she goes but I left off the inner brass washers whilst pinning the crankshaft and bent it slightly on re-assembly. Although the valve is rather stiff and the crankshaft's bent the engine runs given enough air. Now waiting for me to make another crankshaft and ease the valve where it's binding on the guide. Then beautifying. Your paint and wood work photos have given me something to aspire to. The engine build is temporarily paused while I play with a computer project but it's still top of my metal bashing list.

Dave

The method I used on the brass banding wasn't one of my better ideas I used two way sticky tape the rivets are just dummy, but the darn stuff starts to peal off and I have to press it back down, for the follow on engine I drilled through the banding into the cylinder and used some small M2 dome headed cap screws to fasten it down, you can get the screws from model fixings http://www.modelfixings.co.uk/

I had terrible trouble the first time I tried to clad a cylinder then someone told the trick of first gluing the batons with copydex to a piece of cotton material then cut to shape and fix the whole lot to the cylinder, the batons are coffee sterers.

You can get the graphite from Macc Models or Blackgates but you could use ptfe thread tape that you get from plumbers merchants just twist it into a string and use a graphite packing works just as well.

Hope this helps

Stew

Hi Dave

Pleased you got a runner we all go through a learning curve no mater what we attempt, the important thing is to learn from mistakes and don't give up.

Stew

Thanks. LOL, trust me to ask the awkward question!

I've used the rolled thread tape dodge I don't know how many times on full-sized steam plant years ago, glad to see at least some of my skills transfer across to the smaller scale stuff. At least it was a step forward from my old boilerhouse foreman's dodge of pulling a string off the floor mop and using it to pack a leaky gland with. 

Edited By Hopper on 28/01/2018 13:10:24