Type7 - Robbe Rebuild.

[subkraft]

That is certainly something I have wondered about......

I'll have a play around with swapping the batteries and tank. If the tank was more central perhaps it wouldn't matter if it filled stern first.

Thanks.....I'll reassemble and post alternative arrangement.

[JWLaRue]

The robbe Type VII conversions that I've seen in the past all centered the piston as close as possible to the c.g. of the prototype....which would be beneath the aft periscope.

-Jeff

[subkraft]

Thanks for advice!

A rework is in hand to swap the batteries and tank around. Motors will have to be changed so threaded rod can extend between. Think it can just be made to fit.
Back to the laser cutter again.....

[subkraft]

Original arrangement showing tank in relation to hull:



....tank and batteries swapped around:

[ober freak]

That setup looks much better!

[subkraft]

Good.

Got the revised motor bulkheads back from the cutter:



If it all works okay the motors will sit lower in the hull as well.....tight fit

[JWLaRue]

Definitely looks much better!

-Jeff

[salmon]

That really does look great and looks like the placement will help too! Good looking and functional!

[subkraft]

Thanks!


...piston rod to be a close fit past motor casing. Will have to file out gearbox housing. Have another look at the cad file before I start I think...

[subkraft]

It's been a while......but I finished it.
Took so long to get parts revised at laser shop.....6 week wait everytime.
So I bought one.....not solely for hobby use, of course. But great to be able to fab up your own bits.



Changed the motors to 12v....6v was high amps, it was too 'hot'. I found it hard to get a good speed controller arrangement with 6v. Maybe it should have been brushless motors. I also reworked the stern section and control connections....magnetic coupler instead of trying to get the tiny allen key right down the bottom. Magnets just find each other. A magnetic switch would have been good too, I had an engel unit, but just couldn't find the space. Could not get the original solenoid arrangement to work, tried to replace with arduino parts, but I think they are for a much higher voltage.

Thanks for for your help and comments with this.

Next project? I seem to have acquired several of those older D&E gas subdrivers over the years. I want to develop a partial replacement to turn them into a semi aspirated system. The airbrush gas is extremely expensive here....and fittings different.