Mark V Control Sheave Replacement Issue

[Teggy]

I have a 1989 year old Mark V (500) that I inherited and I've been using for quite a while now. I've stripped it down and cleaned it and kept up on maintenance as best I can for its age. Last week I had the control sheave bearing go bad rip apart. I ordered a new control sheave assembly from Shopsmith and it arrived today.

PROBLEM: The problem that I am having is that the shaft key on my machine is wider that the key way in the new control sheave.

Any ideas as to what I should do? Is it necessary to buy the entire assembly with the shaft and the sheave together and I was just too naive to think I only needed the new sheave?

Thanks for any insight,
Matt

[wa2crk]

Matt
You may want to check with Customer service come Monday. If it is/was necessary to buy the entire assembly customer service should have advised you. I have replaced several control sheaves for people and never ran into that problem. Any measurements you can provide would be a big help. Also we like pictures here so if you can please post some of your problem and I think that someone here will be able to help
Bill V
PS It is possible that the key is deformed. When that bearing goes bad and the control sheave starts to wobble on the shaft it is possible that the key can become distorted and a a result not fit inside a new sheave keyway.
Bill V

[JPG]

I think you need to get a new key. Replacing it can be a booger. The clip retaining the idler sheave is difficult to remove.

You may need to file the key to get the idler sheave off(same keyway size as the control sheave. The key is modified to be captive in the shaft under the idler sheave.

Are you sure the current key is 'wider'? The end tends to rise in the keyway making it appear higher.

Take a hard look at the key. You may be able to file it to remove the deformed part.

[Teggy]

Thanks Bill and JPG for the quick responses. Here are the pics. The shaft key and my old control sheave key way are both 0.4 cm (4 tenths of a centimeter) and the NEW sheave key way is 0.3 cm (exactly 3 tenths of a centimeter) (Yes I know you guys are woodworkers and know how to measure but just making sure I'm being clear in my descriptions.

Shaft Key.jpg (45.47 KiB) Viewed 2330 times

Old Control Sheave Key way.jpg (32.28 KiB) Viewed 2330 times

New Control Sheave Key way.jpg (35.46 KiB) Viewed 2330 times

[JPG]

Thanks Bill and JPG for the quick responses. Here are the pics. The shaft key and my old control sheave key way are both 0.4 cm (4 tenths of a centimeter) and the NEW sheave key way is 0.3 cm (exactly 3 tenths of a centimeter) (Yes I know you guys are woodworkers and know how to measure but just making sure I'm being clear in my descriptions.

Shaft Key.jpg

Old Control Sheave Key way.jpg

New Control Sheave Key way.jpg

Let me inform you what they should be(ignore the old one).

1/8" i.e. 0.125" They ain't metric. === 3.175 mm

The keyway(s) may be slightly wider to provide some clearance.

[Teggy]

haha yes JPG they should be in inches (this is America!) but in this case, it was easier to see the difference using metric since my ruler doesn't have 1/32" markings (it stops at 1/8's). I was just trying to show the difference clearly.

In either case I still have the problem that my old key is too big to fit the new key way

[JPG]

haha yes JPG they should be in inches (this is America!) but in this case, it was easier to see the difference using metric since my ruler doesn't have 1/32" markings (it stops at 1/8's). I was just trying to show the difference clearly.

In either case I still have the problem that my old key is too big to fit the new key way

Get an OEM one!

That idler shaft really needs a cleaning.

[Teggy]

Yes Sir!

And yes it does, I'm working on that too

Do you know which replacement part it is on shopsmith.com?
I believe it's "REF:108 Part# 501320 Short Key" if I'm reading it right.

[JPG]

Yes Sir!

And yes it does, I'm working on that too

Do you know which replacement part it is on shopsmith.com?
I believe it's "REF:108 Part# 501320 Short Key" if I'm reading it right.

YEP! Get 107 also(504189) You may not need it, but finding it elsewhere is nigh onto impossible. Besides you might snarf up the current one getting it out.

[Teggy]

Great thanks JPG! I'll post an update back here once I can get the parts in.
Do you know if there is a guide to replacing the key? Haven't ever seen one but I know you've posted a lot of how to's on here.