The Workshop Progress thread 2018

I got the burner and base for my wee Robbie finished off so thought a couple of pictures were in order, seems like blue is the popular choice for these engines.

I did try it with Mamod fuel tabs without the base and it ran OK on them going nearly the full 10min burn time before slowing as the engien got a bit hot, I was nor running any cooling water. However the style of base I made would not work with the tablets as there was not enough air and the flame soon went out.

So a change of firing method was needed, I settled on a modified camping gas stove as this draws it's air from outside or in this case up from under the raised display base and also offers more control over the flame not to mention less of a smell.

As seems to be the usual case the engine did not want to run once it was all back on the base, I eventually traces this to the flywheel being a bit close to the bearing and rubbing but not before I had tried it with a bit more heat than I should which resulted in a scorched base and one of the joints opening up

Anyway the base repairs can wait, here is the video. Ruler make sit look a bit shorter than it is but still only 4 1/2 " from back of cylinder to front of chimney.

Is that from the Polly castings?

Neil

No all carved from solid or fabricated except the flywheel which is a Stuart 10 size casting.

Scaled down to 24mm bore from the Alyn half scale drawings with suitable alterations for size and not using castings.

This "naked" shot of it sat on my tailstock shows the bare materials.

Edited By JasonB on 15/10/2018 12:16:24

I'm not a fan of hot air engines, but I have to admire the workmanship and appearance of the finished article.

Nice one Jason.

Jim

Completed (mostly) building my dividing head. Having said that, I've got a random dividing plate that SWMBO picked up on a whim; at some point I'll make up a worm attachment for it. Now if only I could remember why I needed a dividing head in the first place...............?

Nice little runner there Jason.

George.

Edited By mechman48 on 15/10/2018 17:02:09

Well as I got the Robinson running nicely last weekend I thought I would see if my luck would hold out a while longer so got the R&V vertical out and spent most of the day tinkering with that. It's now close enough to being a runner that it can be stripped and painted as any further adjustments will only be minor and should not risk mucking up the paint.

J

One step forward and 2 steps back on the Overcrank. I made the base, just a piece of ali sheet with 6 round holes for the crank bearing supports and 4 elongated holes for the cylinder block. What could possibly go wrong?

When I offered up the cylinder to the base I found out. The holes in the cylinder base were incorrectly positioned and although I could have used them the cylinder would have been 90 deg out and pointing acrtoss the base instead of along it. The correct positions are marked out in the picture below.

"Oh, pooh sticks." I said, and went for a lie down while I considered whether to scrap the base or the cylinder block. After a while when calm was restored I came up with a simple plan and plugged the M4 holes in the cylinder base and redrilled them in the correct place.

After that I made the crankshaft bearing supports. Here is the base with one shaped support and 1 blank (the third is set up on the milling machine).

For some time now I have been muttering within earshot of the Domestic Authority that I could do with somebody to talk to while I'm busy making important stuff in my "playroom" as she calls it. I have let it be known that a dog would probably fit the bill despite her lifelong objection to domestic animals making a mess in her nice clean house.

Well to day she gave in and came home with my new pet. Meet Doug:

I'm not sure she is taking this matter seriously.

Jim

Finally managed to finish off the grinder tool rests today. Seems like I've been working on them for weeks.

Also cobbled together a nichrome wire perspex bender. I've got a few sheets of coloured 4mm thick stuff that I'm planning on making into drawer dividers.

Hi

I have a Stuart 10V i'd like to paint and do a bit of lining on. I've done some lining with an old fashioned draughtsman pen but wanted to try a lining pen. I found some 'blunt dispensing needles' and used them to make a lining pen. My initial trials have given some pretty good results though I need to learn more of the technique. I made some video's to share the idea if anyone should be interested. 

**LINK**

**LINK**

**LINK**

Nigel

Edited By tractionengine42 on 01/11/2018 20:44:57

Nigel

thats very interesting and informative thank you

PS the last link won't work but I've managed to view it through the tube

regards

paul

Thanks Paul,

The needles cost less than £2 the set and all the other materials were just some off cuts so a very cheap and quick project, the practice takes longer than the building.

I missed a digit off the last link, here it is again.

**LINK**

Nigel

I decided to make the bearing supports and bearings for the IF Allman from scratch as the supplied castings had a couple of issues so over the last couple of days have machined those which allowed me to work out how to mount the larger timing gear and the eccentric that is fixed to it. All seems to turn over nice and smoothly.

I see full size Robinsons at vintage rallies during the summer and I have one of those burners with its stand to boil my tea kettles, its one of the best I've bought for camping.

Martin P

A bit more on my Boxer oscillator, trail assembly of 1 Cylinder, piston, back crank plate. Haven't touched it for some time, other stuff came to the fore... . Not really over enamoured with the crank plates assembly as it stands at the mo'... there is alternative arrangement that can be used but will percy veer with this arrangement for now...



… and for the eagle eyed can you spot deliberate mistake ?



George.

A full size example, running on a wood fire.

Ian S C

Thanks Ian, I think you posted that on MEM and I used it as a ref when making my base.

Made the conrod for the IF Allman this weekend

It's jobs like this that make CNC appealing but do I really need it when I have got Alibre to give me some tool offsets and a DRO so the mill can be set to these?

Started with a bit of 16mm 6082, drilled a couple of holes that will be easier now than later and then squared the ends with a couple of full depth passes.

Made a start with a 12mm high by 1mm deep pass all round

Then worked my way up in 0.5mm increments

Until I got to a height where a 12mm bull nose cutter could be used for the other half of the ogee

Then did similar to the corners except I used 1.0mm steps

Then a bit of hand work to blend in all the steps.

If you have not used a spiral point tap for through holes you have been missing out, I cut this M8 x 0.75 without backing off the tap and the swarf shown all came out the bottom of the hole rather than clogging up the flutes like you would get with a traditional tap.

Edited By JasonB on 18/12/2018 19:17:24

Jason, you have made a nice job of that, you say a bit of hand work to blend in all the steps, but what tool/tools did you use.

Also how does the tip of the tap differ, its a bit difficult to see from the picture. If like the name suggests it has spirals just at the tip they must be quite short..?

Ron

Nothing special in the hand tool department, mostly a 6mm square file to blend the stepped convex part, a 10mm round file, few grades of emery and a bit of 12mm steel bar to wrap the emery around as well as around the sq file.

As the name suggests it is only the point or end that has a spiral which due to being so short looks more like an angled flute here, unlike a drill the flute is left handed so pushes the swarf down.

You can see the spiral a lot better on spiral flute taps which have a longer spiral and that is right handed so it lifts the swarf out of blind holes here and below.