New Project Started!

[NickG]

Hi all,

Well, I've finally got my butt back in the workshop and started my next project. I am on leave all week so the plan was to spend 2 hours in the morning and 2 hours in the evening each day, the aim being a completed project.

After a bit of deliberation I've decided what I'm making.

Here are some of the materials:


Any ideas? This pic might give a better clue:


The wheel was an old casting I got many years ago and machined quite badly but never used it on anything. I thought I could probably put it to some use now so I set about trueing it up in the lathe.


Not quite finished, it'll need drilling and tapping for a grub screw.


That's all I got done today, I couldn't do the morning session due to other things getting in the way. I am going to do my best to make sure nothing else gets in the way as otherwise I definitely won't achieve my goal.

Nick

[RobWilson]

Looking good Nick

What sort of engine ,,,,Hot air may be ?     sounds  like this post will be something to tune into daily 

Regards Rob

[NickG]

Almost right Rob!

A few other members will know I've been banging on about making a flame gulper for some time now so this is going to be my attempt! It's going to be based pretty much on Jan Ridders internal valve one just with a few simplifications. I was planning to do a 3D model and draw it up on CAD but that would take some time and I have a good opportunity to get in the workshop this week, so I'm keeping most of his parameters. A few things will need to be altered to accomodate the flywheel and burner though which will save me some time.

For about the first time ever I've actually been and bought some materials for this project, they normally come from off-cuts of scrap I've collected over the years but I thought I don't have much time to mess about.

I went to a local model engineering material supplier - I only found out this place was about 7 miles from me a couple of years ago but have never been. The materials in the first photo cost £12.50 which I thought was reasonable. 3/8" x 3" HE30 alloy, 40mm cast iron, 25mm cast iron, 2mm stainless and 10mm stainless. Just about to order my bearings from Arc Euro Trade, hopefully postal strike won't affect their delivery!

I just hope it works. I managed to make a working stirling engine but I think I'll need to pay more attention to the fits on this one.

Nick

[RobWilson]

Hi Nick

Great price on the materials ,,,,,,,must be great to have some were local,,,,,,,,,Jan Ridders  has some great designs ,i have a few of his engine plans ,one day i may get round to building one ,,,,i have a flame gulper there a good engine to run ,mine sounds like a 2 stroke motor , i wish you all the best with the build


Regards Rob

[NickG]

I thought it seemed pretty good, it will be really handy having them just down the road. Here is their website, just incase their prices work out better for anyone, they do deliver and take cards etc. http://www.m-machine-metals.co.uk/index.htm

Yes I like Jan Ridders engines too. I've always been fascinated by flame gulpers so it's been on the list to make one for a long time, hopefully I will be ticking it off shortly!

Thanks Rob, I think I'll need it! 

Nick

[RobWilson]

HA HA HA HA HA HA HA HA  Darlington , well i never just down there today Nick , pleased you posted link if i get time i think i will call in for a look ,as i am back down there tomorrow ,,,i live in the  Newcastle area

Hows the build coming along ?

Regards Rob

[NickG]

  Small world! I didn't realise but if you do pop in, there is another company opposite that metal place that is a professional model engineers - they do large scale traction engines and the like. You'll need a seat before you see the prices but it might be interesting for a look!

Build is going slowly! Everything on this engine is bigger than I am used to so the metal is taking longer to remove! Also, I keep getting interupted, we bought a new bed at the weekend, but it doesn't fit in the current place in the bedroom so I said I'd move the fitted wardrobe to another wall - I meant eventually, not before the bed is delivered! Wife and parents seemed to have other ideas and the wardrobe has now been ripped out, which means cobbling together laminate floor (where bits are missing underneath it) and the room will need repainting after - stupid bed!

I did get a bit done yesterday though so pics to follow...

Nick

[sbwhart]

Nick

When you've got spare time, everyone thinks they are doing you a favore finding you jobs so you don't get board, since I've been retired, my wife find me jobs, my mother in-law finds me jobs, my dad finds me jobs, I keep telling them I'm quite happy and busy in my shop not getting boarded at all do they take the hint  NO

Have fun

Stew

[websterz]

Hey Stew...I got a little project I could use a bit of help on. 

[Stilldrillin]

Stew! 

Are you any good with bathroom suites? 

David D

[sbwhart]

I'm staying quite
 


Stew
 

[NickG]

Yeah point taken Stew! I actually think this could be dad trying to keep himself busy as he's just retired! The wife and I said we were quite happy to leave it for now but as soon as my dad got a whiff of what I was planning he wanted to be involved! Then he said it'd be better to do the work before we got the new bed arrives - otherwise it would never get done, which was exactly my intention!  

Never mind, I'm back out there after I've written this little bit up. I can't even do my write up after the workshop session since we're sleeping in the spare room where the computer is and the wife complains the typing noise keeps her up!   can't win!

Anyway, yesterday I decided to make a start on the cylinder since this is probably one of the more complex parts on this engine.

I started by skimming 1 end of the lump of cast iron to give me somewhere true to grip:



Turned around in chuck and the OD rough machined down to 0.5mm oversize. All the dimensions for this are metric so am having to do a bit of conversion with the dials. I actually think I prefer metric sizes now, it’s just most of my stuff is imperial. Might adopt the new system! Also centre drilled and drilled straight in with ½” drill (biggest I have) to a bit longer than the required 50mm depth.


Bored the hole out to size. This took a while as I only have a crappy TC tipped boring tool which isn’t very ridid. I have a big boring bar too but I don’ t think it fits in the tool post and is too big for this bore in any case. Finish wasn’t amazing as the tipped tool has a chip out of it but not bad considering.


Decided I would finish turn the OD at this stage, back to a nice slow feed. So why am I getting such a crappy finish now when it was OK before?


Was just about to start pulling my hair out when I thought I’d re-check centre height:


Only about 3/16” too high! I’d used the same setup plus the bit I used for the boring bar! That could be why! Finish much better now that’s corrected:


Next comes the scary bit – putting the grooves in, only it’s not actually scary anymore on this lathe – at least not on cast iron, brass and aluminium. I am deviating from the drawing here in 2 ways. 1. I just made the grooves the width of my parting tool (happens to be 2.15mm) and calculated how many would fit, and 2. I made them 6mm deep instead of 7mm as I went oversize on the bore by 1mm.


Parting off at about 200rpm under power.


Finished groove, worked really well.


I was going to stop for a break ½ way through as I thought the tool would be getting red hot, but it wasn’t even warm. The cylinder was luke warm so I just continued. Here it is with all grooves cut and a bit of a de-burr and polish.


Parting off  leaving 0.25mm to skim off other end:



Why is it I mess about with all these tools to get a good finish and the best bloody one is the parting tool?!


This picture shows that I only JUST drilled and bored the hole deep enough! Lucky there.


I don’t normally bother lapping the bores on my little steam engine and didn’t on my hot air engine, although I tried to ream that one I didn’t lap or polish the piston. But on this one, I thought I’d better pay more attention to the finish of the bore and pistons if I want it to work. So I chopped a bit off the brush handle and turned it down to a bit under the bore.


Then put a saw cut down the middle and wrapped some wet & dry around it. Medium then fine then fine with oil.


Seemed to work a treat, well happy with the result. Back off into garage now to hopefully finish the cylinder. Didn’t get my morning session in due to stupid bedroom!


So far I am trying to pay more attention to detail on this project, and I am using known materials. Hopefully, if I can keep this up it will turn out to be my best one yet. I just hope it will work, fingers crossed!
Nick

[sbwhart]

Looking good Nick
 

Stew

[Darren]

Nice machining (if you forget the dodgy bit  )

Don't forge to post later ...... 


Tip, there is always the sofa ....

[NickG]

So, I'd done what I thought was the hard bits on the cylinder so I clamped it in the vice on the milling machine and started machining the flat for the intake port. I used a brand new cutter to give me a good finish and it was going well:

So far I am trying to pay more attention to detail on this project, and I am using known materials.

 

That must have been tempting fate!

This happened:




This was caused by the vice not being tight. I'd got down to my 7mm depth 1 cutter wide and I thought instead of doing all that again it would be easier to control if I now used the side of the cutter to cut where I wanted to in the Y direction. As soon as I tried this the thing slipped and dug in. The vice felt nice and tight, the only thing I can think is it was it was at it’s extreme of opening so I didn’t have much thread engagement and it wasn’t actually tightening, just causing damage to the thread. Will have to strip the vice down to find this out.

So the rescue mission started with taking the jaws off the vice and clamping, this time it did tighten and I was able to half-save it. The wall is a little thinner than it should be and there is still a fair of a divet out of it so am a bit gutted, but it should still function.

All I did after this was cut the port, which actually turned out slightly bigger than the 3mm it should have been. I guess I shouldn’t have used a 3mm end mill! Or maybe I could have got away with it if I hadn’t drilled a hole at each end first. I will need to make sure there is enough meat on the valve to let it close fully but it should be easy to adjust.

Cutting the port.


How it looks now.


Still a bit of work to do on this - Two small flats need milling for the pillars, then drilling and tapping. Then drill the long hole drilling 4mm and turn up bronze bushes for each end.

There’s no point trying to rush this, it’s definitely not going to be finished by the end of the week and if I do, other errors are likely to happen! Realistically, the end of next week is now the aim but I’m not going to get myself beat up about it, if it doesn’t happen –tough!

Nick

[sbwhart]

Nice rescue Nick, its always a bummer when something like that happens, you may be able to hide the divot later on in the build with a bit of bling shiney brass bit.

Have fun

Stew

[Bernd]

Nick,

From that one picture it looks like you were "climb" cutting. That would be one reason that happened to you.

Nice save on the part by the way.

Bernd

[NickG]

Bernd,

I was climb milling as I thought it'd see if it gave a better finish so that is why it got dragged out then and not before, it was only the tiniest of cuts though. It was when I tried setting it up to attempt to save it when I found the vice wasn't clamping properly - not sure what's happened there. Will need to investigate, it clamped up fine when I removed both jaws though.

Stew, I never thought of that. I might be able to bolt a brass plate over the top or something if it works!

Hopefully I'll be able to finish the cylinder tonight and put this mishap behind me!

Nick

[Darren]

Nick,

Some things I have found with climb milling..

You must have no backlash in the leadscrew/nut. Otherwise the milling will seem to be going fine and then suddenly the table jumps to take up the backlash.
This forces the cutter to dig into the work further pulling the table quite violently. At the same time the cutter tries to drag itself out of the collet holder forcing it deeper into the work.
Something has to give, either the work which can be dug into, or it get ripped out of the vice and across the room.
Or the cutter snaps, again usually causing more damage to the work.

Some machines are designed for climb milling, such as my Beaver, by having two sets of feedscrew nuts to totally eliminate backlash. Unless you have these then climb milling is always going to be a disaster waiting to happen.

Proven several times on my Sealey milling machine 

[CrewCab]

Nice going Nick, you'll get over the minor divot I'm sure 

Why is it I mess about with all these tools to get a good finish and the best bloody one is the parting tool?! 

You've already answered that one Nick   


Good thread, looking forward to more.

CC

[bogstandard]

Nick,

Don't worry about covering up the blunder, the wick will take care of that, besides, after a few runs the area will be filthy black anyway.

The only thing to really worry about is if going slightly deeper has changed any of the running or starting characteristics. They are a pig to start at the best of times, until you find the sweet spot for the flame.

I couldn't get mine to run at all with Jan's angled wick design, and came up with my own fixed position vertical one, which gives much better running and starting. In fact when I told and showed Jan about it, he incorporated it into his latest twin cylinder design, which runs very well.

The most critical part on this engine is what you should be coming to soon.

Make sure you have the barrel bore and piston perfectly smooth, parallel and lapped together. The piston shouldn't drop down the cylinder, but gently slide it's way down under it's own weight. There will be no lubrication used in the bore at all, the two parts are designed to be self lubricating, by using the carbon content in the cast iron of each one. Oil will stop it dead, and it won't restart until you have cleaned every trace out with spirits.

John

[NickG]

John,

Good point, probably won't be able to see the blunder.

Thanks for the advice on the piston / valve. I think this could be the bit I struggle on. I noticed that Jan changed his design after yours and did a bit of a study to show the best place for the wick. He seems to think it is vertical and right behind the port, seems strange but am sure I will have to try many positions.

Might tackle the piston tonight, I still need to make the small bushes for the cylinder too.

Nick

[bogstandard]

Actually Nick, it was myself that gave Jan the original settings for the wick, but mine were based on 1/4" (6.4mm) not the 8mm he has ended up with. I found that the 1/4" gave the best all round performance, and I experimented with both larger and smaller. Without the vertical wick, as soon as you try to move the engine, it will stop dead. With the vertical wick, I can actually carry the engine around and even run it outside, a thing that Jan marvelled over, as before that, it was almost impossible. That has to do with the position of cold air pockets around the inlet hole. Getting too technical now, so I will leave you to it.

I am sure that you will get it sorted.

A little bit of advice you won't find on Jan's plans, wash out the ballraces with spirits to get rid of the grease and put only a tiny amount of thin oil in them. The friction reduces dramatically and will really help when you come to get it running.


John

[NickG]

Darren, good point there about climb milling. I’ve managed it in the past but maybe it was the softer materials that allowed me to do that. I am going to avoid it like the plague in future now!

Good tip there John, thanks. I received my ball races from Arc Euro yesteday and although I obviously haven't tried them properly, there did seem to be a bit more drag than the ones I used on my hot air engine, but they felt smoother at the same time.

Right, will post last night’s progress. This was basically finishing off the cylinder, that is, milling the two flats + drilling and tapping for the pillars and drilling the long hole for the valve rod.

Setting up perpendicular to the port face to mill flats:


Flats milled – nearly took 2mm off but thought it look enough when I got to just under 1, so checked the drawing again and it was infact a 1!


Holes centre drilled:


Opening up to tapping size – changed this to 2BA which was nearest I had to 4mm:


Tapping – was thinking of doing this under power but leaving it not too tight in the collet so it would slip. Chickened out though and turned the spindle by hand! I was always taught to go 1 turn forward ½ turn back anyway.


Set up to centre drill and drill the long hole. I used the square just as a check that it was clamped correctly.


It worked really well with the 4mm drill, didn’t seem to wonder off at all, it’s come out spot on.


The only thing was, there was something funny happening with my milling machine when drilling that long hole. It felt like something was binding, either the spindle or gears the further down I went on the travel. Will have to look into that, I know the guy that bought the same one at our club has had trouble with his so will have to investigate.

Right off to attempt the piston / valve now I think!

Thanks to all for your interest, support and advice. 

Nick

[Gerhard Olivier]

Good work on the cyl Nick

Watching with interest

Gerhard