Drive shaft slippage on Papa.

[Davidh]

Hello all,

I have have a problem with a brass drive shaft slipping, as it rotates on a motor shaft. This is for the twin motor cylinder of my new Papa class boat. I made the cylinder myself and made this brass shaft machined up to extend from the motor shaft out through the seals and then the coupling to the prop shafts. Initially I used Loctite but just recently the shaft started slipping on the motor. I pulled it apart and ground a flat section at the end of the shaft that buts up against the motor. I then drilled a tiny hole into the flat and attempted to drill a similar hole in the flat of the motor shaft. I couldn’t drill, the motor shaft steel just won’t budge , as I thought maybe I could insert a tiny pin through the holes in both shafts. No luck so I applied more loctite. It’s started slipping again. Aargh!!!

This afternoon I thought, how about trying to solder both together. I tried and tried and it held for a while then.....

does anybody have have any Suggestions?


David H

[MFR1964]

Try some small diameter silicone hose, works for me at the 212

Manfred

[JHapprich]

dont solder, wont work. diameter of the coupling big enough to drill a threaded hole and secure the shaft with a grub screw? even if youd achieve drilling through the motor shaft the engine torque would break your pin BUT you can gring a flat surface on the engine shaft to counter the groub screw (dremel+ stone disk). if there is no space, sand the engine shaft rough, make a new shaft extension with a slight tighter hole then the motor shaft, heat the extension up and force it over the motor shaft. Jörg

[Albion]

If you solder it you need to throughly clean the motor shaft and the internals of the brass.
Secondly you need an agressive acid flux, and lastly a high power soedirng iron to get the heat in there (ungar work well)

Slot cars have far more power at the shaft and they have soldered on Pinions which stay on, just need to do a proper job on the soldering

[JHapprich]

yes, but i guess slot cars are using 540` motors with a 3,17/3,2mm shaft. arent that 400`with a 2mm shaft on PAPA? ps are that pinions you mention actually soldered and not welded?

AHH. mistranslatet. you mean slotcars like carrera etc? those engines have welded pinions afaik

[JHapprich]

https://www.youtube.com/watch?v=-FhfO0I98Sc

I stand corrected

pinion is not a small pin i see. here is some german lesson: pinion = Ritzel pin = Stift

now thats mean;-)
-> http://www.rcindependent.com/wbb3/in...threadID=76524

[Albion]

yes, but i guess slot cars are using 540` motors with a 3,17/3,2mm shaft. arent that 400`with a 2mm shaft on PAPA? ps are that pinions you mention actually soldered and not welded?

AHH. mistranslatet. you mean slotcars like carrera etc? those engines have welded pinions afaik

Not like carrera i mean like this

https://www.proslot.com/part.php?part=PS-VX300

116,000RPM 1095 gm/cm torque, pinions soldered on.

[Stephen Vick]

Solder the brass tube into a DuBro wheel collar drill through the grub screw hole then you can tighten the grub screw onto the flat you have filed on the motor shaft.