Poppin Engine build.

[ian_in_the_midlands]

Slow progress today.
The aluminium mandrel (should I be calling it an arbour?) was used.
Both flywheels were turned to final diameter and the centre was bored out.
I had problems with chatter. I suspect this was caused by flex in the soft aluminium, and maybe a blunt tool.
Then the centres for the 4 spoke holes were marked and centre drilled.
The tool marks were polished out before drilling out the holes.
I started on the pillar drill, but it was apparent that I was going to get a grab, so I fitted the 4 jaw chuck and started boring on the lathe.
Near disaster - I did get a grab, and the wheel was pulled from the chuck. Luckily the flywheel was not in too bad a shape. Some small marks around the circumference that I will be able to turn out without losing much of the diameter.
The wheel re-chucked, I bored again, this time going up in smaller increments. The first two holes went okay.
It is getting late now, so stopped whilst still ahead.

[Stilldrillin]

I like the way you made the cam, Ian! 

It's all shaping up, nicely........   

Any suggestions for a better method I could have used?

If it works for you, and the part is correct. That's the best method........ 

David D

[vtsteam]

I've been following Ian, and you've been doing very nice work while learning.

One question, did you stone a tiny flat on your drill tip lips before trying to drill the brass flywheels? Otherwise brass does really tend to grab.

Kind of hard to explain what I mean by "a flat" , but if you place the drill vertical tip down on a table, the direction of the flat would be parallel with the axis of the drill -- vertical. And it is very slight amount of stoning -- almost invisible.

I usually lay the stone flat on the bench, hook one lip of the drill bit over the edge on top, with the drill bit running parallel with the edge of the stone, and give it a swipe along the length of the stone. It should be a fine stone. Then do the other lip.

[ian_in_the_midlands]

No I haven't.
Somebody told me that that drills for brass are ground differently.
My previous attempts of grinding drills have been hopeless, so I thought instead I would just use brand new drills.

If it is simply grinding a flat I would hope I could do that.
I will investigate.

Thanks.

[Stilldrillin]

Have a look here, Ian.

http://users.bart.nl/users/summer/16mmngm/Articles_htms/ColinBinnie/DrillSharpening.htm

David D

[ian_in_the_midlands]

Back onto the flywheels today.

The set of drill bits I have are Tin coated, so I could not flat the end as advised. As most of my drilling is probably in brass, I will buy another set and modify them.

Too impatient and the in-laws over, I needed to get on in the garage, so I continued with the drills I have. Taking the holes out very carefully in 0.5mm increments, I had no more problems.

I then reamed the holes to final size, and finally gave each one a tiny chamfer with a drill bit.

The wheels were then re-mounted onto the mandrel, and the chuck marks were skimmed off. The wheels 'rang' as I was doing this, and the result of this can be seen on the finish of the rims. Varying the speed had no effect on the surface quality. The picture looks much worse than it is, and a polish with emery paper removed this marks. The wheels are now slightly smaller (0.5mm in diameter, 0.2mm in width) than the plans ask. I do not think this will make any difference, but that will teach me not to turn to final size too quickly.

It can be seen in the picture that there are still some chatter marks on the inside of the rim. I can not get rid of these so will have to live with them. I will put the worse side inward when I assemble the engine so that they are not so apparent.

Finally I mounted both wheels on a piece of steel, pushed the bearings on the end, and held these in the lathe. Spinning the wheels by hand showed a minute amount of wobble on one wheel. I will wait until the engine is assembled  to see how bad the problem really is before I start trying to fix anything.

[ian_in_the_midlands]

After looking at the pictures posted I had to go and check  - I think the marks on the first photograph that look like awful scratches on the spokes must be thumb prints, as I can not see anything there now. Panic over!

[ian_in_the_midlands]

This weekend I moved onto the connecting rod.
A length of 2.5mm silver steel was drilled and cut to length.
I decided to harden the piston end, so it was heated to cherry red and quenched in water.
I then re-heated it to straw colour and let it cool naturally.

Slots on the brass parts were cut using a slitting saw with the piece held in the tool holder. The sides were then milled to size.

Everything else was basic turning/ drilling/tapping.
Once assembled, the hole for the crank was drilled and everything was polished. I turned a wooden dowel and used brasso to get inside the hole.
The steel shaft was then threadlocked in place. The photo shows how I aligned the axis by eye. The plans call for a rivet to hold the shaft in place, but I will leave this for now in case I need to adjust the length in the future.

I made the yoke a few days ago, again using the slitting saw.

The parts were then assembled. There is a slight skew.  I suspect the hole may not be quite straight. I think it will be okay.

The yoke is attached by a piece of drill bit. It is only a press fit, but it is long enough that the inside of the piston will stop it falling out.

[ian_in_the_midlands]

Everything assembled. Starting to look like an engine.

Now to make a start on the standard.
A 2" length was sawn from a piece of 1"x2" aluminium flat and faced off in the lathe to size.

That's enough for today. Now time to work out how I can make the standard without a milling machine

[vtsteam]

You're doing a really beautiful job, Ian. 

[Manxmodder]

 Progressing nicely,you're doing a grand job Ian  ......OZ

[ian_in_the_midlands]

The weather has warmed up a little, so back in the garage to continue with the standard.
Holes were drilled/bored/reamed.
The drilling guide was used to drill the 4 holes through which the bolts will pass that hold the cylinder on.
I am unable to check alignment of these yet, but fingers crossed the holes are in the right place.
I also made the base.

I now have a problem: How to remove the material to complete the standard.
To keep things simple I will keep with square edges rather than the radiuses on the plan

My options are:
1. Drill/saw out the waste and file. Good practice with a file, but is this really practical? Am I more likely to end up wrecking my work?
2. Buy a milling machine. I can not find the room in the garage without selling my woodturning lathe. I need to think hard about this option in the future.
3. Buy a milling attachment for my mini lathe. So far the majority of advice seems to be to avoid this. I am still looking out for one at a sensible price.
4. Find someone with a milling machine willing to help me. I will try a post in the "Request for work" section.

In the meantime, there are of other parts for me to be getting on with.

[vtsteam]

I'd just file it -- it doesn't look like that much work. Rough the convex parts first with a nice big rough cross cut flat bastard file, then finish with a finer file. The hollow can be done with a coarse rat tail and a finer round file, the same way

You could cut out a profile of each end from thin sheet steel using tin snips and a file to smoothe it,  and attach it to both ends of the block. These will serve as guides, if you're worried about spoiling your work. File close with the rough file, and then file to the guides with the fine file.

Filing is fun.....if you treat it that way, and you aren't working for someone else! 

[ian_in_the_midlands]

It is not the amount of work in the filing that concerns me, but my level of skill. Anyway, with your bit of encouragement vtsteam, I thought I would have a go.
After marking out, the holes were drilled at the corners of the waste. The main lump to go was then removed with a drill/jewellers saw/hack saw as close to the line as I dared.
Some filing was done to get close to the lines, bit I need to order some smaller files before I can get into the gap and complete this.

I could now test the cylinder fit against the stand.
It was bolted in place. I am very slightly off to one side (very slightly isn't really an Engineering  term is it?). I must have bored the large hole slightly off. It is so small an error that this will probably not show once the standard has been polished.

The good news is the cylinder is upright  .

Thought I would put the flywheels on for effect  .

[NormanV]

In engineering there is precision and there is "what you can get away with". I am often surprised with how much I can get away with. Just keep trying.

[Stilldrillin]

Ian.
If you don't tell us. We'll never know about your, "good enoughs". 

You're doing a great job. Progressing well...... 

David D

[SwarfnStuff]

"(very slightly isn't really an Engineering  term is it?)" Oh I don't know? It fits right in there with, "a whisker, a smidgeon, (aka smidge) and a tiny bit".     Depends on the accuracy really needed for the job in hand.
John B,
 p.s. I guess i shall have to look at reply with quote.

[ian_in_the_midlands]

Weekend spend sawing/drilling/filing.
(Note to myself - find space in garage for milling machine and buy one!)

I decided I would follow the plans and put the radiuses in.
I still have some more filing and polishing to do. I also need to cut the slots for the crank and tap the holes for the screws that clamp the bearings.

Some pictures of the progress:

[Stilldrillin]

Weekend spend sawing/drilling/filing.
(Note to myself - find space in garage for milling machine and buy one!)

Ian.

You know it makes sense........ 

Some pictures of the progress:

Nice! 

That's a lot more progress, than I've managed. Since before Christmas Eve. 

The most comforting thought..... The hardest part, is behind you now. Mebbe! 

David D

[awemawson]

Oh dear . . now you are HOOKED 

Yes you NEED that milling machine, after all EVERYONE needs a milling machine, but that's just the start, next it'll be a shaper or some other machine, then before you know it it'll be an extension on the back of the garage 

It's an addiction - I should know I'm addicted 

[vtsteam]

And, of course, a second tiny shop......

wait, back to no mill again.............nooooooooo!   

Beautiful job on that -- more shapely! And all hand work. I bet some day you look back on that engine and are proud of that even with a shop full of newer machines. 

[ian_in_the_midlands]

Is this the sort of fuel people are running their flame lickers on:
http://www.ebay.co.uk/itm/141522876949?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
(Isopropanol 99.9%)?
If not, what should I use that is available in the UK without a licence?

Is something like this a suitable wick:
http://www.ebay.co.uk/itm/Wick-Round-Pixie-5-32-1M-length-4mm-x-1000mm-Cotton-Made-in-England-/261705625530?pt=UK_Home_Garden_Lamps&hash=item3ceedeefba

[Stilldrillin]

Hi Ian.

Have a look in your local hardware store, for methylated spirits. It will do the job.

I now use this, as "meths"........ http://www.ebay.co.uk/itm/181622131173?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT   (Though, the offer was for 1 bottle at a time).

Use stove rope, as wick. It doesn't burn away....... http://www.ebay.co.uk/itm/Stove-Rope-Gasket-Seal-for-Flues-Woodburner-Stoves-Door-Glass-Fire-Seals-/320873562369?pt=UK_HG_FireplacesMantelpieces_RL&var=&hash=item4ab58e0101

David D

[Manxmodder]

David, just out of interest,will the ethanol produce less water vapour than the purple meths that we get from the chemist/drug store?   And I wonder which of these fuels burn hotter?.....OZ.

[ian_in_the_midlands]

I had read somewhere not to use meths because it produces more moisture and does not burn so hot.
I had not seen the bio-ethanol before. Would this be better than Isopropanol 99.9%?
Isopropanol would have other uses in addition to being a fuel (Cleaning PCBs etc).

I had not thought of using stove rope.

Thanks.