Tetrix Gearbox Help

[rocketeer1]

The motor will probably need to be geared down a bit, so it would be even better if it was possible to mod the gear box to about a 1:20 ratio (vs the 1:52 it is originally, right?).

[Dad1279]

Have you seen this? http://www.chiefdelphi.com/forums/sh...&postcount=142

[NyCityKId]

Originally Posted by Dad1279

Have you seen this? http://www.chiefdelphi.com/forums/sh...&postcount=142

Thanks a lot. I haven't really gone through that thread because of the sheer number of post. I guess I'll have to buckle down and start reading.

[Hurband]

The Tetrix gearbox can be easily changed from 52:1 (as received) to either 31.2:1 or10.4:1.
When you take off the gearbox end plate by carefully grinding, using a dremel, the 3 tabs you will notice 3 compound gear sets each on a separate shaft. 2 are identical.
If you connect (stack) the 2 identical gearsets by lets say by soldering them you will find that by some axial endplay adjustement these will fit nicely and you will have a 31.2:1 gearbox. You may need to push the motor drive gear onto the motor shaft and even grind down its length a little bit.
To get a 10.4:1 reduction stack and attach one of the intermediate gearsets with the input and with even less axial adjustment you will have a 10.4:1 reduction.
The motors can drive a 4 inch wheel with 31.2:1 reduction and with light enough bot you can climb in ~ 2.5 seconds.
I calculate that with 10.4:1 and 2 inch wheels you can climb under 2 seconds.

[Hurband]

The Tetrix gearbox can be easily changed from 52:1 (as received) to either 31.2:1 or10.4:1.
When you take off the gearbox end plate by carefully grinding, using a dremel, the 3 tabs you will notice 3 compound gear sets each on a separate shaft. 2 are identical.
If you connect (stack) the 2 identical gearsets by lets say by soldering them you will find that by some axial endplay adjustement these will fit nicely and you will have a 31.2:1 gearbox. You may need to push the motor drive gear onto the motor shaft and even grind down its length a little bit.
To get a 10.4:1 reduction stack and attach one of the intermediate gearsets with the input and with even less axial adjustment you will have a 10.4:1 reduction.
The motors can each drive a 4 inch wheel with 31.2:1 reduction and with light enough bot you can climb in ~ 2.5 seconds.
I calculate that with 10.4:1 and 2 inch wheels you can climb under 2 seconds.

[Chris is me]

Throw the gearboxes away. They're terrible.

[bhsrobotics1671]

Originally Posted by Chris is me

Throw the gearboxes away. They're terrible.

and then do what?

[Akash Rastogi]

Originally Posted by bhsrobotics1671

and then do what?

Let the motor loose.

[Grim Tuesday]

Or to be more specific, use a smaller wheel as your gear down stage.

[Chris is me]

Originally Posted by Grim Tuesday

Or to be more specific, use a smaller wheel as your gear down stage.

I wouldn't call it a "wheel" anymore.

And that's all the hints I'm giving.

Optionally, if you want to use a wheel, you can take the transmission and knock several stages out. Keep just the final 40 tooth gear and the brass gear stage. It's pretty easy to make them line up and mesh.

Even the simple addition of grease will make your gearboxes better.

[TerryS]

Originally Posted by Hurband

If you connect (stack) the 2 identical gearsets by lets say by soldering them you will find that by some axial endplay adjustement these will fit nicely and you will have a 31.2:1 gearbox.

We tried soldering two of the gearsets together, but we couldn't get the solder to stick. Tried 60/40 rosin core and silver bearing acid core. Do you need to use a special flux or do some special surface prep to be able to solder them together?