Motor with wrong gears ?

[neil phillips]

Tried to get this mount driven from TS Germany. But the speed was off. Here was there reply after they looked into it. 

Wonder if anyone remembers these motors handsets ect ? Is there a solution to this problem ?. Any gears that could replace this ? Pics attached 

Its a shame if couldnt sort it. Any insight appreciated. Wonder if its worth doing a wanted ad for 12 gear cogs that could fit ?

They said the mount was a skyview EQ4 ? 

just got reply from our engineer.

He hast tested the motor drive left here on stock and found out that either with 6V and also with 9V the motor exactly runs with double speed because of a wrong gear wheel (wrong number of teeth).

This is exactly what happens with your drive too.

The wheel on the mount has 60 teeth ...on the motor there are 24.  But the motor should have 12 to get the correct speed. (or any combination in 5:1 ratio would work)

Unfortunately we don´t have any replacement gear wheels which could fit here an I could send you.                                                                   

[JamesF]

Someone like MotionCo might be able to supply a suitable replacement for the 24-tooth gear, but the tricky bit may actually be working out what to replace it with as there are plenty of gear profiles and spindle diameters to choose from.  Assuming you can get the correct spindle diameters it might be easier to replace both gears with a matching pair of the correct ratio.

James

[JamesF]

An alternative might be to replace both gears by timing pulleys in a 5:1 ratio with a belt.  You'd not get the reversal of the direction of rotation then though, so you'd probably have to use it with the handset in southern hemisphere mode.

James

[neil phillips]

12 hours ago, JamesF said:

An alternative might be to replace both gears by timing pulleys in a 5:1 ratio with a belt.  You'd not get the reversal of the direction of rotation then though, so you'd probably have to use it with the handset in southern hemisphere mode.

James

Thanks for the feedback James. Never used motor pulleys before. Who could i approach about that ? do you know.

[CraigT82]

There isn't a serial number on the 24t pulley anywhere is there? Googling it could lead to it's specs and possible a 12t version? 

[wulfrun]

You need a pair of gears in the right ratio AND size and tooth-pitch. You can't just swap out the 24t for a 12t because it'll be smaller and won't mesh (stating the obvious, I know). Might be worth looking to see if radio-controlled models would source something suitable. What type of motor is it? It should be feasible to make the motor run at half-speed too.

[Seelive]

13 minutes ago, neil phillips said:

Thanks for the feedback James. Never used motor pulleys before. Who could i approach about that ? do you know.

MotionCo also do a range of pulleys and belts.

[neil phillips]

35 minutes ago, CraigT82 said:

There isn't a serial number on the 24t pulley anywhere is there? Googling it could lead to it's specs and possible a 12t version? 

Cheers Craig i will check

[neil phillips]

31 minutes ago, wulfrun said:

You need a pair of gears in the right ratio AND size and tooth-pitch. You can't just swap out the 24t for a 12t because it'll be smaller and won't mesh (stating the obvious, I know). Might be worth looking to see if radio-controlled models would source something suitable. What type of motor is it? It should be feasible to make the motor run at half-speed too.

Thanks for the info the only thing i know about the motor is TS thought it would be suitable for the skyview mount I have no experiance with halving the speed of the Motor TS germany refunded me. So good service from them

[CraigT82]

45 minutes ago, wulfrun said:

You need a pair of gears in the right ratio AND size and tooth-pitch. You can't just swap out the 24t for a 12t because it'll be smaller and won't mesh (stating the obvious, I know). Might be worth looking to see if radio-controlled models would source something suitable. What type of motor is it? It should be feasible to make the motor run at half-speed too.

I *think* it might be possible, looking at the pics of how the motor attaches - by a single bolt - to simply rotate the entire motor around the fixing bolt to make the new 12t gear mesh with the existing 60t gear?

Edited May 11, 2021 by CraigT82

[CraigT82]

10 minutes ago, neil phillips said:

TS germany refunded me

Very good of TS 👍

[JamesF]

45 minutes ago, CraigT82 said:

I *think* it might be possible, looking at the pics of how the motor attaches - by a single bolt - to simply rotate the entire motor around the fixing bolt to make the new 12t gear mesh with the existing 60t gear?

That was my assumption.  It looks as though it may be possible.  Otherwise it's probably easier to go the belt & pulleys route.

James

[JamesF]

1 hour ago, Seelive said:

MotionCo also do a range of pulleys and belts.

Indeed so.  They would be my first port of call for that, but as already mentioned, people who specialise in radio controlled models, or even parts for building robots might be worth a look too.

James

[wulfrun]

48 minutes ago, CraigT82 said:

I *think* it might be possible, looking at the pics of how the motor attaches - by a single bolt - to simply rotate the entire motor around the fixing bolt to make the new 12t gear mesh with the existing 60t gear?

Good idea, I'd overlooked that possibility. I'd say there's a strong chance a RC car/truck motor pinion would work, assuming you can find the right pitch. It's probably standard so you may be in luck. You'll need the pitch and the motor-shaft size information.

[JamesF]

5 minutes ago, wulfrun said:

You'll need the pitch and the motor-shaft size information.

Vernier calipers should do for this I think, if you can measure the diameter of the motor shaft and the diameter of the output gear across two opposing teeth.

James

[johninderby]

Motor pinion gears might work. Try spmeone like Modelsport or another RC model shop. 3.2mm, 5mm and 8mm are common shaft sizes. eBay has lots as well.

https://www.modelsport.co.uk/?products[query]=motor pinions

Edited May 11, 2021 by johninderby

[wulfrun]

Something of this ilk, off an RC rock-crawler I have. This one is a 14-tooth but other sizes are readily available:

[neil phillips]

Thanks for all the suggestions guys. lots of helpful info. I will have to look into it. But might be worth experimenting it seems