775pro .5" Hex Output Shaft

[Lireal]

What is the best method to press a gear onto the 775?

[Sam Skoglund]

Thanks for the input! It looks like I should either drill better holes in hex shaft, or use the 32DP gears. Does anyone know of a 5mm bore 5mm HTD pulley?

The reason I am doing this instead of a versaplanetary gearbox is because last year we had issues with shredding the weak little gears in the versaplanetary. Will the 12 tooth 32DP pinion gear from WCD hold up to high pressure is there are a few other stages after it in the gearbox? Or if it is a high stress mechanism, should I try to use the hex shaft adapter method instead?

[R.C.]

Originally Posted by Sam Skoglund

The reason I am doing this instead of a versaplanetary gearbox is because last year we had issues with shredding the weak little gears in the versaplanetary. Will the 12 tooth 32DP pinion gear from WCD hold up to high pressure is there are a few other stages after it in the gearbox? Or if it is a high stress mechanism, should I try to use the hex shaft adapter method instead?

The pinion itself should have no issue, we have some pinions on our 2012 robot... That look brand new. The gears on the VP are different from the WCP gears. They are used in different applications all together. So its not an apples to apples comparison.

We will have stock of all of the 32dp gears and belt pinions sometime next week.

[asid61]

Originally Posted by Sam Skoglund

Thanks for the input! It looks like I should either drill better holes in hex shaft, or use the 32DP gears. Does anyone know of a 5mm bore 5mm HTD pulley?

The reason I am doing this instead of a versaplanetary gearbox is because last year we had issues with shredding the weak little gears in the versaplanetary. Will the 12 tooth 32DP pinion gear from WCD hold up to high pressure is there are a few other stages after it in the gearbox? Or if it is a high stress mechanism, should I try to use the hex shaft adapter method instead?

Because the 775pro is a high-speed low-torque motor, even when stalled it shouldn't break a 32 pitch gear. I calculated an approximate tooth force of 17lbs, and a tooth strength of 72lbs according to this calculator: http://www.botlanta.org/converters/dale-calc/gear.html so you have a pretty large factor of safety there.

Of all the failure modes I have seen from a VP, shredding gears is not one of them. That doesn't mean it's never happened, but you should make sure you used the correct planet and sun gears on the right carrier plate.

[Knufire]

Originally Posted by Sam Skoglund

Thanks for the input! It looks like I should either drill better holes in hex shaft, or use the 32DP gears. Does anyone know of a 5mm bore 5mm HTD pulley?

The reason I am doing this instead of a versaplanetary gearbox is because last year we had issues with shredding the weak little gears in the versaplanetary. Will the 12 tooth 32DP pinion gear from WCD hold up to high pressure is there are a few other stages after it in the gearbox? Or if it is a high stress mechanism, should I try to use the hex shaft adapter method instead?

SDP-SI has those pulleys.

A 6Z25M0xxDF0905 is the part number, where xx is the number of teeth (11-14)

[R.C.]

Originally Posted by Lireal

What is the best method to press a gear onto the 775?

We took a tube and machined a holder for the 775pro. Then just used an arbor press to push the pinion on.

You can 3d print a mount/holder as well. Probably can skip the holder, we've pressed them on free hand before as well. But we got to a point where we were pushing on 30+ pinions a season and didn't wanna bend any output shafts.

[AlexanderLuke]

Originally Posted by R.C.

We took a tube and machined a holder for the 775pro. Then just used an arbor press to push the pinion on.

You can 3d print a mount/holder as well. Probably can skip the holder, we've pressed them on free hand before as well. But we got to a point where we were pushing on 30+ pinions a season and didn't wanna bend any output shafts.

Do you happen to have any pictures of this machined holder? We have been pressing on pinions free-handed for the most part, I am curious to see how your mount helps with the process.

[cbale2000]

Why not just use a 1/2" Hex versa-planetary with no reduction? The tolerances will be much better and you'll have the added bonus of standard mounting holes.

[pmangels17]

Originally Posted by cbale2000

Why not just use a 1/2" Hex versa-planetary with no reduction? The tolerances will be much better and you'll have the added bonus of standard mounting holes.

True that you could definitely do this, but if you are going through the trouble of building a custom gearbox, why add extra parts when you could just put a gear on the motor shaft and skip the extra weight/space/added friction (friction is minimal) of a 1:1 COTS gearbox?