Mounting Sprockets to the Rover Wheels

[Ice Berg]

Hey,

So I was mounting some AndyMark aluminum sprockets to the rover wheels and I noticed that the holes in the wheels are smaller than those in the sprockets. How have other teams been dealing with this? I ended up using machine screws that fit through the wheel mounting holes, but because they're smaller than the holes on the sprocket, it shifts around.

Any suggestions?

[gorrilla]

we just gave them a little tap with the rubber mallet

8/32 bolts with lock nuts and locktite

[Matt382]

Someone in this thread said that locktite dissolved the plastic on the wheels. I would not recommend using lockite in that case. We decided right away that tapping the holes and screwing steel bolts into plastic was not a good idea (even though it was suggested in the intructions for putting the chassis together) so we drilled the holes out bigger and got longer bolts and bolted the sprockets all the way through with some nylon lock nuts on the other side.

[gorrilla]

Originally Posted by Matt382

Someone in this thread said that locktite dissolved the plastic on the wheels. I would not recommend using lockite in that case. We decided right away that tapping the holes and screwing steel bolts into plastic was not a good idea (even though it was suggested in the intructions for putting the chassis together) so we drilled the holes out bigger and got longer bolts and bolted the sprockets all the way through with some nylon lock nuts on the other side.

locktite does NOT dissolve plastic at all

[EricH]

Originally Posted by gorrilla

locktite does NOT dissolve plastic at all

I haven't seen it happen, but there have been many, many reports that locktited plastic parts break.

I know my team (used to) simply tap the holes of the AM wheels and put the screws in.

[gorrilla]

Originally Posted by EricH

I haven't seen it happen, but there have been many, many reports that locktited plastic parts break.
.

from the locktite website

"Threadlockers should only be used on metal-to-metal applications, because the Threadlocker turns into a plastic-like substance."

which is probobly the cause.....

[Rich Kressly]

The holes are intentionally small. AndyMark included instructions for tapping and connecting the sprockets to the wheels in the KOP. These instructions are available via a video at the AM website here: http://lib.store.yahoo.net/lib/yhst-.../AM09WNick.mp4

[Daniel_LaFleur]

Originally Posted by gorrilla

locktite does NOT dissolve plastic at all

This is somewhat incorrect.

Depending on the type of loctite and the type of plastic it can craze and crack plastics. The general suggestion is to test the loctite product on a small, non critical, portion of the plastic to see if there is a reaction.

And if you don't believe me, try Loctite 496 on a piece of polycarbonate

[gorrilla]

Originally Posted by Daniel_LaFleur

This is somewhat incorrect.

Depending on the type of loctite and the type of plastic it can craze and crack plastics. The general suggestion is to test the loctite product on a small, non critical, portion of the plastic to see if there is a reaction.

And if you don't believe me, try Loctite 496 on a piece of polycarbonate

locktite meaning, threadlocker blue,green and red....

[EricH]

Originally Posted by gorrilla

locktite meaning, threadlocker blue,green and red....

Yes, that sort of thing. Try it first on a non-critical area.

[gorrilla]

Originally Posted by EricH

Yes, that sort of thing. Try it first on a non-critical area.

we've always used it, its kinda too late now

i doubt it could though,

and not just on the wheels......

[Mr_I]

Originally Posted by gorrilla

locktite does NOT dissolve plastic at all

Well, I hate to contradict you, but 811 unfortunately knows better.

[gorrilla]

Originally Posted by Mr_I

Well, I hate to contradict you, but 811 unfortunately knows better.

i read this, it seems they just poured it in the holes?

if it was the blue threadlocker, then alot of people are in for some troblue

and we put our everything together with it
maybe thats why it says to use it on only metal to metal applications

i still doubt this though,

[McGurky]

Follow the instructions on Andy Marks Website, it explains what size screw to use, and how to tap the holes on the wheels!

[BJT]

I like to use a 10-32 bolt that puts about 1 inch into the wheel. we run a tap in about .75 inch. The last .25 without threads makes it nice and tight.
I have just run them in without tapping but then they can't be disassembled without the threads getting screwed up.