No weld grinder pillow blocks

M.Griffin

M.Griffin

Joined
Nov 8, 2007
Messages
460
So I have my grinder built from Tracy's plans, but have run into a problem. It appears my drive shaft (5/8") won't fit into my 5/8" pillow block bearings. Is there some trick to get them in? They are way too tight. I already tried greasing the shaft (insert joke here) and pressing the bearing on with a clamp, but it doesn't even seem close. I also filed and sanded down the end of the rod to make sure there isn't a burr or it isn't out of round. Is there a lot of variation in the diameter of 5/8" cold rolled steel round rod? I have to drive an hour to get another piece to try. Any insight? Thanks.

-Mike
 
Put the shaft in the freezer for a day or so and leave the bearings out in the heat/sun, and give that a shot. if not get some emery cloth and go to work on that thing.
 
I think drive shaft would be precision ground, and also be keyed so your pulleys or drive wheels don't slip. I've seen cold rolled stock have quite a bit of variation. If you try another cold rolled rod, take the bearings with you and try before you buy, but mail ordering drive shaft may be a cheaper option.
 
you could check a local machine shop and see if they have any shafts kicking around.
 
cold roll is usually over size by anywhere from 5-10 thousandths, sometimes more.you could spin it in a drill and try to sand it down to size, but progress is slow going and usually uneven. Best thing would be to simply get some percision stock or find someone with a lathe that will turn the shaft you got to fit the bearings.
 
I would think you would actually want to use a shaft as well.

CRS rod is rarely actually round, and seldom a true size.

If you want a smooth machine, start with smooth parts.
 
Mike, did you measure the O.D. of the shaft and the I.D. of the bearing block ? Use a "hey mikey" for the shaft and a snap gauge(telescope gauge) that you'll measure over the top of with a mike for the bearing I.D. That'll at least give you an idea of whats going on.
 
Do the rest of the components fit the rod? Pulleys and drive wheel?

Like everyone said, the rod is probably oversize and also out of round. If you happen to live close to me, you can bring it by my shop and I'll grind it for you for beer and conversation. Cut a keyway too.

Otherwise, getting a piece of ground rod is cheap. Hell, you could get ground W1, then you can forge on the drop...

The free shipping code at enco for June is WBJP8, but it only works on an order of $50 or more.
 
Use 120grit sand paper and stroke it like you own it. It will go. Just like the other guys say, cold rolled is not high precision stuff. Stephen's idea of precision ground 01 is a good one. You do want a pretty snug fit though so it doesn't spin inside of the bearing races. I've put quite of few of those together and I've had to sand most of them with 120grit at least a little.
 
Stephan, thanks for letting us know about Fastenal!!!!
I'm going to be needing a drive spindle and didn't have a clue where to get it!
 
i finished my no-weld about 2 months ago and at first had the same problem. and sanding and cutting a keyway was another thing to have to do. i spent $24 and bought a 3ft 5/8 shaft with a keyway already the whole length from fastenal. i bought quite a few pieces of sq. tube from them also. their great to deal with and they also carry 01 and A2 for a decent price.anyway after i got the keyed shaft from them all i needed was a bit of lube and all was well! good luck!! willy
 
I apologise for being Mr Obvious but no one's mentioned this yet (atleast not that i saw anyway)...There should be a Cam lock or a Collar lock on either side of the pillow block you may need to loosen it with a hex key first, before the shaft will fit through.

+1 for Fastenal
 
Thanks for all the ideas. Today I got the chance to take a long lunch and run to the steel yard. They don't carry any precision ground round rod, so I am going to have to order it if my new piece isn't perfect. I had my bearing with me so I tried a bunch of different types of 5/8" stuff they had. None of it fit and I tried about 20 different sticks of the stuff. I asked the guy there and he didn't have any idea why none would fit. It seems like if it was just a lack of precision, some of it would be too small, but it was all too big (what little mac said makes sense here). He pointed to a different rack of cold rolled rod so I tried it just to humor him and it was a perfect fit, tough to get in, and no play at all so I bought it ($3). He had no idea why. I will have to mic the two rods and see what the difference is (I knew I bought that nice old mic at a yard sale for $5 for a reason).

To answer a couple of questions: Yes, I sanded and sanded, but it still wasn't even close. No, the shaft didn't fit into the drive wheel or the pulley, but I didn't force it since it is steel vs aluminum and I didn't want the drive wheel to lose that fight. Nathan, thanks for the offer, but CA is a long drive from NC. Thanks again. Now I have to go put it together and fire it up.

-Mike
 
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