Member postings for Roger B

Milling on a mini lathe is quite feasible. Basic requirements are a vertical slide, some clamps to hold things to it (gravity is not your friend here when trying to set things up), some collets to hold the milling cutters and some milling cutters. Here are a few pictures of set ups I have used when I was starting out:

Another option might be an open injector. I made this as a trial with a non return valve and a 0.2mm (8 thou) orifice.

There was not enough atomisation for the diesel but it might work injecting into a vaporiser

https://youtu.be/fS5owr5DIJQ?si=uHH1illsu5NXe2nC

I will write this as thinking out loud. If I am going away from what you want, please say, this is based on my experience.

I have a working mushroom/poppet injector with a basic dimension for the valve of 1.4mm, 55 thou. This works with a full diesel with a water cooling. How this would work with a hot bulb I am not sure. The length can be reduced, it is designed to fit an existing cylinder head.

I think that the spill valve on the injector will be too difficult, a dummy could be made for appearance.

I would suggest a variable stroke injection pump. This could be partially hidden in the base and connected to the governor. Do you have your expected bore and stroke? I can then calculate a suitable injection pump bore.

Springs need to be looked at. They need to be flat ended to avoid side pressures. I buy commercial springs, but they have a cost.

Hello Frank, I think we made contact on MEM a few years ago and you sent me a package of drawings. I have got them out and will see if I can suggest anything.

This is unusual compared to more modern designs in that the spill valve is on the injector not on the pump.

Did you ever try the 3" scale pump and injector?

Keeping the hot bulb hot will also be a challenge at this scale.

As the Ackroyd engine only requires a low pressure fuel injector this should be feasible. I have made a selection of high pressure injectors (100 bar) for a full diesel. What size are you looking at?

This is a 20cc full diesel, the injector body is 10mm square, the nozzle is 5mm diameter.

https://youtu.be/nHYDfQaNw98

I have a manual Proxxon MF70 that I use with the Proxxon supplied single flute carbide end mills. This company offers ER11 conversion spindles as well as a speed reduction system:

Zubehör Proxxon MF70 - USOVO

I thought about making my own conversion to allow me to use my smaller throwaway cutters and purchased an ER11 Chuck with a 10mm x 100mm shank from CTC:

https://www.ctctools.biz/er11-10mm-x-100mm-straight-shank-collet-chuck-l29/

It is still on the to do list as I have been able to do all I need, including milling rocker arms from key steel, with the standard Proxxon cutters.

Here, Switzerland, I was able to buy Diethyl Ether at the local chemist (Apotheke). This was for use as a starting aid for my diesel.

Thank you all for your interest. I have emailed the .dwg and .pdf files.

It appears that imperial materials have been used in a number of places but can probably be replaced with metric stock. I don’t have the small imperial hex key required to dismantle the plunger assembly but I am sure you can work out what it will be like inside.

I have dismantled and measured my tumbler reverse and have drawn it in DraftSight but there dosen't seem to be a way to upload a .dwg file.

The various sectors and large holes are quite rough, possibly plasma or water jet cut.

I can send the .dwg by email if requested.

I will try to take some measurements of my tumbler reverse over the next couple of evenings. I don't think that there are many critical dimensions.

TECO may be able to supply you the table without the milling head and column. They supplied me the head and column to fit to my MD65.

TECO Znojmo

TECO still manufacture a version of this lathe:

TECO Znojmo

They may be able to help. Pro Machine Tools used to be the uk agent but they don't appear to be active any more:

Pro Machine Tools website | Model Engineer (model-engineer.co.uk)

Maybe it should be Jeantaud Steering

Turn, turn, turn: The great fib about who really invented Ackermann steering | Hemmings

I use Proxxon carbide milling cutters in a Proxxon MF70 (max speed 20 000rpm).

PROXXON 3 Piece Tungsten Milling Cutter Set | Axminster Tools

These work well on brass, aluminium and steel. I have cut keyways in moderate carbon steel (ST50) and milled rockers from keysteel (C45k).

There are some pictures in my album MF70.

As you say, not a lot of information. 12mm is a fairly standard thread. The other important measurement is the thread length. If you can measure this then look on some European moped websites you may find something that will work.

This a reasonable quality M6 x 0.75 LH die:

Round Dies, left, Mf, DIN 223 (DIN EN 22568), HSS-G, 6 x 0.75 » VÖLKEL SHOP (voelkel-shop.com)

£16.07, the devil is probably in the postage.

I don't know if this German supplier will fit your requirements or if shipping to the UK will have become too much of a problem.

Threading tool sets | VOELKEL Threading Solutions (voelkel-shop.com)

I use them for obscure threads like M8 x 0.5.

Excellent I wish you success with getting it running as a hot bulb engine.

Long long ago I made a simple oscillating steam engine from a car brake cylinder. This was coupled to a bike dynamo and a small light bulb. Steam came from my mother's pressure cooker on an electric cooker. Input heat around 2kW. Light bulb 6V 0.5 A 3W. Efficiency negligable

The Swiss produced a full sized electrically fired steam loco to deal with their lack of coal during the second world war.

The Swiss Electric-Steam Locomotives.........Lasik (douglas-self.com)

Beware of the Douglas Self site You can get lost in there for hours (days).