Help me remove key from shaft?

sicesp · Aug 17, 2017

I purchased an old 7" Baldor bench grinder, which I am trying to rehab. The shaft has a 2 keys, one on each end, to fix the flanges.

I can't remove the hubs without removing the keys because the hubs themselves have no keyways.

The type of key employed, is a tiny cylindrical split tubular structure, driven through a round hole, perpendicular to the shaft, protruding 7/64". If I must destroy the key in its removal, how would I rectify that?

Thanks.

HuFlungDung · Aug 17, 2017

I think you are referring to what we call a roll pin, or a spring roll pin. Typically, you just drive them on through with a pin punch of the proper diameter.

Please tell me that the hole goes right through

aliva · Aug 17, 2017

If you can't grab it with pliers and pull it out, grind it flush to the shaft and put proper wood ruff key in next to it on the shaft

sicesp · Aug 17, 2017

Shaft is solid unfortunately. It's a blind hole.

sicesp · Aug 17, 2017

I will try the grinding I suppose. Thanks.

Forrest Addy · Aug 17, 2017

Using a Dremel tool with a cut-off wheel, grind a couple of shallow slots just above the shaft so the slot bottom is parallel to the shaft axis. Use them to get a grip with hefty end-nipper pliers like these:

Channellock 357 7" Hand Cutting Nipper End Cutter Pliers Made in USA | eBay

Fitting the jaws in the shallow slots, and with thin soft metal to protect the shaft, pry the pin from the shaft. It's sure to tight but not impossible to move.

Measure what you can of the pin so you can replace it. I suspect its a roll or spring pin as Hu suggested. Does it look like either of these?

Spring pin - Wikipedia

Look under: "rolled spring pin"

and near the bottom of the article under "slotted sprig pin"

Both are common for semi-permanent fixation of assembled parts. They are cheap, available in a wide variety of sizes, and are intended to be driven in with a hammer and removed from through holes by driving it through with a punch or if in a blind hole, extracted like a bad tooth with a stout grip with pliers. Do not re-use them unless the come out pristine. Replace. Most shop people keep a small kit of common size spring pins. .

Chip Chester · Aug 17, 2017

You might be able to use the 'hydraulic' removal process, if the split pin is pinched together tight. Fill the pin with grease, then take a close-fitting punch and tap the grease in with hammer taps. As the grease is put under pressure, it may push the pin out from the bottom up. A tight fitting punch and a tight, non-leaking pin are required for this to work, but if it does work it'll come out clean with no other work required. Worth a try.

Chip

David J. · Aug 17, 2017

If the roll pin is not to hard ( think brittle ) I sometimes have luck with vise grips and
a slide hammer to pull them.
If shaft seems to have lots of diameter avail. maybe drill through with a small drill
( for location ) then drill the side opposite the pin just slightly smaller then
pin diameter and use a punch to drive it out.
I've also tig welded the slide hammer onto some, carbide drilled some....
just escalate till it's out.
One of those designs that should require the engineer to have his dick
slammed in a car door!
David

Jim Williams · Aug 17, 2017

If you can get the pin out as Forrest suggests, drill the hole on through the shaft and install a new roll pin. The pin will be easy to remove by driving on through if you ever need to remove it again.

true temper · Aug 17, 2017

Keith Fenner has a video on a grinder rebuild. About 8 minutes in deals with the pin. https://m.youtube.com/watch?v=9xRy8wGfcIk

bhigdog · Aug 17, 2017

A number of way to skin this cat. Twer it me I'd drill down through the pin hole to locate the through hole. Then drill from the bottom with a larger drill than the split pin until I hit the pin. Should be able to then drive the pin out with a drift smaller than the pin diameter but larger than the pin's hole. I'd just use another roll pin to put it back together.

But that's just me...............

sicesp · Aug 17, 2017

Thank you for the awesome ideas. Here's how it went down:

Broke a punch off in it. Being brittle, the pin finally broke. I tried drilling it but it's seems hardened, guess I don't have the right tools.

Finally, I just ground the pin down flush with a dremel cut off wheel.

Q: is a pin or key really necessary? (Bear with me, some of you may consider that an idiot question)

Leaving that aside, I've ordered bearings with closest measurement I can find: 17mm bore, 40mm o.d.

The shaft has a small shallow axial bore on the end, I'm thinking for a bearing puller to fit. Getting a 3-jaw puller from H.F. sound good? Then I'm working out how I'm going to press the new bearings on...

Monarchist · Aug 17, 2017

sicesp said:
Broke a punch off in it. Being brittle, the pin finally broke. I tried drilling it but it's seems hardened, guess I don't have the right tools.

Finally, I just ground the pin down flush with a dremel cut off wheel.

Too late now.. common as fly-poop on small goods these annoying buggers are.

Proven way to remove is not pliers.

Similar to Forrest's approach, but faster and cruder. Diagonal side-cutters, rather. Not your good ones.

Dig in, jaw slot aligned shaft long-axis, not across the curve. Rock on the curved body of the dikes, use a thin, flat putty-knife blade for next-step fulcrum, or about an 8" jemmy of the sort usually sold for setting and adjusting wooden door frames and removing trim.

Come right out, they do.

Try that next time.

You didn't really think field service techs who do this s**t every day traveled around with a whole machine-shop on their toolbelt, did you? Dikes, rather.

steve45 · Aug 17, 2017

Depending on the speed of the motor, you could just turn it on and stand back! :crazy:

Of course, this is not the best practice, and you may never find the pin...

sicesp · Aug 17, 2017

Can I squeak by without having any pin or key?

Monarchist · Aug 17, 2017

sicesp said:
Can I squeak by without having any pin or key?

"Squeak" is a good word, actually. Hard on shafting and such, though when it rises to "shriek".

But surely. Just TiG it on. No squeak. Dead silent.

Why d'you think the OEM went to the expense and nuisance of keyslot, hole, pin, and labour?

Surely wasn't LOOKS, was it?

Who would ever see it?

extropic · Aug 17, 2017

sicesp said:
Can I squeak by without having any pin or key?

Not recommended.

steve-l · Aug 18, 2017

This is a common issue with many machines and is easily resolved by using Keith Fenner's video recommended in reply #10. It works perfectly and causes no damage.

Monarchist · Aug 18, 2017

true temper said:
Keith Fenner has a video on a grinder rebuild. About 8 minutes in deals with the pin. https://m.youtube.com/watch?v=9xRy8wGfcIk

Thank for saving the agony of the first eight minutes.

Skipped to the end about 12 minutes in. Started that video back in 2012?

Has he gotten the roll pin out yet?

magneticanomaly · Aug 18, 2017

I like to heat the pin enough to anneal before gripping to pull. Loss of springiness reduces pin's grip in hole. Then if you break off the part that protrudes, you can tap the inside of the pin to pull with a screw and slidehammer.

Help me remove key from shaft?

Plastic

Diamond

Aluminum

Plastic

Plastic

Diamond

Diamond

Cast Iron

Stainless

Stainless

Stainless

Plastic

Diamond

Stainless

Plastic

Diamond

Stainless

Titanium

Diamond

Titanium

Similar threads