The insides of CO2 motors

[g_kandylakis]

A separate thread, to document the various motors and what they consist of.

As a start, the instructions manual of the Czech Modela, with an exploded view in the last page.

[g_kandylakis]

A similar leaflet, this time for Gasparin motors, a GM 120 used as an example.

[g_kandylakis]

...

[g_kandylakis]

No such luxuries when Bill Brown was making his motors...

Here is a disassembled MJ-140 twin, before cleaning and reconditionee.

[g_kandylakis]

and the piston pieces...

Partly explains their quality and higher cost at the time. Miniature engineering...

[Nigel_M]

Thanks for sharing the photos of the Brown insides. Were you expecting questions? Oh well, (re)move me as you see fit.
I initially assumed the plastic part of the piston would 'obviously' be made via injection moulding but then noticed what appear to be turning marks on the upper truncated cone as well as inside the bore. Then I wondered about timing of when these were made - iirc Nylon 66, a fairly typical injection moulding plastic, was introduced in the 1940's but these were available earlier than that? Can anyone correct my hazy knowledge please? I have no idea about the history of injection moulding, I'm not even sure if Bakelite would have been simply cast? 

[g_kandylakis]

Hi Nigel,

the purpose of any forum is to discuss and exchange information. If I didn't want any questions I would lock the thread or post the images otherwise 

The Brown MJ series was produced in the 70s and 80s, so no issue about injection molding possibility.

I imagine the plastic parts were injection molded, otherwise I think it is very difficult to achieve the thin sealing lip by machining.

As to the turning marks, probably a not too perfectly finished mold tool?

George