Pulley Slipping on D shaft: What should I do? 5

[artbme21]

thread406-235196

Hi,
I am having a problem with my pulley slipping on a D shaped drive shaft. I just read the referenced thread and learned from Compositepro that a D shaft isnt designed for high torque operations. I suppose I made a few assumptions, one being that this is not a high torque operation. I guess it is. No matter how tight I make the set screws, the pulley ends up loosening up.
Do I need a different pulley or a different shaft?..or both?

This is the pulley I am using:

http://www.mcmaster.com/#pulleys-for-belts/=7smyh3

It has 2 set screws

this is the shaft I am using:

http://www.mcmaster.com/#precision-shafts/=7smz4k

I only need 2 of these to work, so labor over cost is probably the best way to go for me.

Should I even bother drilling a mark in the shaft for the setscrew to key into?
Thanks so much

 

[EdDanzer]

You failed to provide any application information. Torque and RPM, is there shock loads, does the load forward and reverse?

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com

 

[hydtools]

Change to a pulley with a taper lock hub.

Ted

 

[MikeHalloran]

If you need a device to actually work, and keep on working, setscrews should not be a part of it. Just make it a personal internal design rule.





Mike Halloran
Pembroke Pines, FL, USA

 

[artbme21]

I am learning that set screws are indeed evil....so basically I should never use a 3/8" shaft then either. I cant seem to find a keyed timing belt pulley anywhere which means I need to rebuild/replace almost everything that I have built so far.
I am working on getting you the technical information that I left out from my original post.
Thank you for your responses.
Happy 4th for those of you in the states!

 

[mfgenggear]

Aetbeme21

have you tried loctite on the setscrews.

an other easy way to do this, is a thread & nut to hold pulley in place & apply with loctite.

my favorite but more expensive is to drill holes in the pulley & have a flange on the arbor with matching tapped holes. bolt in place with loctite. will never come loose.
& is very secure. I design reishaur & OD grind arbors this way. I never use set screws to flimsy & slip easily.

there must be lots of vibration to loosen the set screws.
what is the vibration. dynamic balance required?

Mfgenggear

 

[hydtools]

Apply Loctite 680 Bearing Mount to the pulley bore and shaft. Use the set screws to hold the pulley in place until the Loctite cures.

Ted

 

[Tmoose]

Where to the setscrews engage the shaft, relative to the "D" ?

D an T

 

[artbme21]

One of the set screws is on the flat part of the D and the other is 90 degrees to that one.
I ended up welding a 1/8" steel plate to the shaft and bolting the plate to the pulley using 1/4-20 bolts.
It looks pretty strong...I will be testing it shortly.
Here is a picture after it was already assembled so it was hard to get a good shot, but I think this will clarify.

Again, thanks for all the responses.

 

[diskullman]

You have gone a long way to customize a pulley, when a split taper bushing will end up giving you a flange to bolt to the face of the pulley

Russell Giuliano

 

[artbme21]

I could not find a split taper bushing with a 3/8" bore, so this was the cheapest and best way to go in the end. I did not have to rebuild everything else, just modified the pulley...worked well and I sure learned a lot.