smashapotamus
1 mW
- Joined
- Sep 19, 2015
- Messages
- 18
I am going to attempt a keyway machining for a turnigy 6374. For those who have done it what did you use for a key or keyway?
6374 Keyway Machining
- Thread starter smashapotamus
- Start date
I have had good luck drilling a dimple on the side of the shaft for a grub-screw. Be aware, Hobby King has spare shafts if you have an issue with the keyway attempt.
smashapotamus
1 mW
- Joined
- Sep 19, 2015
- Messages
- 18
I have considered just doing a flat spot or a dimple for use with a grub screw. It just seems so much less secure than using a keyway.
I'm just not sure where to get the metal key from.
I'm just not sure where to get the metal key from.
Chalo
100 TW
In such a crowded spot, I'd favor a Woodruff key. You'll need a mill or some kind of secure, rigid fixture to cut the key seat.
But spinningmagnets has a good approach. There's not all that much torque on a high RPM motor like that such as to demand a key. How do you plan to key the sprocket bore? Usually that takes a special broach and collet setup, plus an arbor press.
But spinningmagnets has a good approach. There's not all that much torque on a high RPM motor like that such as to demand a key. How do you plan to key the sprocket bore? Usually that takes a special broach and collet setup, plus an arbor press.
It's dead simple. I've recently done 3 of them.
Order some 3mm keyway bar:
http://www.ebay.co.uk/itm/111709885411?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Order your pulleys from someone like belting online and specify a 3mm keyway.
Then, with either a hand file, or a power file, grind off 1.5mm from your motor shaft. As you get close, slow down and keep taking measurements. Use a digital vernier - less than £8 on ebay.
Once you see 6.5, (on an 8mm shaft), stop. You'll need to hammer the keyway bar in, regardless. That'll hold it firm, but to be sure, I have my pullies made with a 3mm grub screw hole. I mark the motor shaft, and then file a "V" with the edge of a file. This guarantees the pulley won't move along the motor shaft.
It's far easier than is sounds. No need for milling semi circular keyways.
Order some 3mm keyway bar:
http://www.ebay.co.uk/itm/111709885411?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Order your pulleys from someone like belting online and specify a 3mm keyway.
Then, with either a hand file, or a power file, grind off 1.5mm from your motor shaft. As you get close, slow down and keep taking measurements. Use a digital vernier - less than £8 on ebay.
Once you see 6.5, (on an 8mm shaft), stop. You'll need to hammer the keyway bar in, regardless. That'll hold it firm, but to be sure, I have my pullies made with a 3mm grub screw hole. I mark the motor shaft, and then file a "V" with the edge of a file. This guarantees the pulley won't move along the motor shaft.
It's far easier than is sounds. No need for milling semi circular keyways.
smashapotamus
1 mW
- Joined
- Sep 19, 2015
- Messages
- 18
Keyway bar is EXACTLY what I was looking for. Thanks!
I already have pulleys with 4mm keyways and grub screws in them. I just needed to locate the bar. My plan was to wrap the motor to protect it from debris, lock the shaft, secure the motor in a vice, and use a dremel to slowly take off material until I can hammer the bar in to the keyway.
Thanks Roger, now I know what to look for. I just need to find an american source.
I already have pulleys with 4mm keyways and grub screws in them. I just needed to locate the bar. My plan was to wrap the motor to protect it from debris, lock the shaft, secure the motor in a vice, and use a dremel to slowly take off material until I can hammer the bar in to the keyway.
Thanks Roger, now I know what to look for. I just need to find an american source.
bandaro
10 kW
You can also mill them out with a ball nose bit (or indeed just flat spot it) and use a circular keyway. A 3mm circular key is just as strong, and much easier to obtain. For my keys, I generally just get a bit of tooling steel (such as a broken drill bit) and this serves as a brilliant key. The exact size, super tough hardened steel and available everywhere.
Maybe he meant this?
bandaro
10 kW
Cheers spinningmagnets, exactly like that.
A key doesn't need to be square shaped, all that is important is that you have a tight even fit everywhere. A 3mm cylindrical pin has about 2.8mm of material that you need to shear through before it will give way, so this easily provides enough resistance.
To make it, use a high quality flat nose mill bit and clamp the shaft/gear together then carefully plunge the bit into it, to drill a hole as shown in the image above. Alternatively, put some waste steel (of same hardness) in the gear as an axle, and drill a hole, then you can either use a ball nose mill bit or even a dremel with a cutting blade to slowly and carefully remove the material from the motor shaft until the gear will press onto it. You will need a mill/bench drill for whatever method you choose. I'm sure google has a tutorial on how to do it too.
Google the correct key size for the 8mm shaft on these motor and use that size, make it as long as the gear is itself (so the key just protrudes out from the gear fractionally).
A key doesn't need to be square shaped, all that is important is that you have a tight even fit everywhere. A 3mm cylindrical pin has about 2.8mm of material that you need to shear through before it will give way, so this easily provides enough resistance.
To make it, use a high quality flat nose mill bit and clamp the shaft/gear together then carefully plunge the bit into it, to drill a hole as shown in the image above. Alternatively, put some waste steel (of same hardness) in the gear as an axle, and drill a hole, then you can either use a ball nose mill bit or even a dremel with a cutting blade to slowly and carefully remove the material from the motor shaft until the gear will press onto it. You will need a mill/bench drill for whatever method you choose. I'm sure google has a tutorial on how to do it too.
Google the correct key size for the 8mm shaft on these motor and use that size, make it as long as the gear is itself (so the key just protrudes out from the gear fractionally).
