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pntrbl
05-07-2007, 01:42 AM
I've been over at the Chaski site reading Harold V's grinding posts and all I can say is, wow, am I off the mark.

My bench grinder is an old American Made 3/4 HP hog that had a spun bearing when I got it for free. Grooved the shaft pretty badly and I didn't have a lathe to repair it with at the time. All I could do was eyeball the shaft in the middle of the bearing and tackweld the shaft to the inner race. :eek: Been that way ever since! :D Works good too. I can lean on that thing and it just keeps on chewing.

It does vibrate a bit tho. As a matter of fact it vibrates a lot!

Before that I briefly owned a cheap Chinese 3/4 that had me so disgusted I gave it away. It was so weak I could hold it down with my left hand and stop the motor with my right. That POS wasn't worth putting a hole in my bench.

But now I'm thinking one o' those Chineys might be just the ticket for bit grinding. I can get a supposedly 3/4 HP model with 8" wheels delivered to my house for under $40. I'll make 1 1/4" arbors for it and run the 7" wheels per Harold's excellent advice.

Whadda you guys think?

SP

dp
05-07-2007, 02:13 AM
I think $40 goes as far as it ever did. It never got you much of a grinder, though, and I'd be surprised if it did now. Write a follow-up if you get it - it might start a stampede for grinders :)

dan s
05-07-2007, 02:17 AM
Should work pretty well.

speedy
05-07-2007, 06:02 AM
I can lean on that thing and it just keeps on chewing.

It does vibrate a bit tho. As a matter of fact it vibrates a lot!

Whadda you guys think?SP

Your wheel is out of wack?

MTNGUN
05-07-2007, 11:09 AM
Plan on replacing the sheel metal tool rests with heavy steel. Not hard to do, and you probably have enough scrap metal laying around to do the job, but it will take the better part of a day's work.

I think I paid $19 for my Chicom 8" bench grinder, on sale at HF. How can you go wrong for $19? Well, it has been gathering dust for several years now, since it is not even usable until I balance the wheels (it vibrates like crazy and that makes the sheel metal rests vibrate like crazy, too, so precision grinding is out of the question .... and I can't true the wheels until I build a sturdy rest to support the truing tool).

The motor seems strong enough. The shafts appear to run true. I believe new rests will transform it into a usefool tool.

Carld
05-07-2007, 11:38 AM
Why not rebuild the American made grinder correctly? It would still be way better than you can get today.

Willy
05-07-2007, 11:45 AM
Before you sell the farm and spend $20-40 on a cheap grinder consider what you may be getting.
Found this on the PM site the other day...scroll down about a third of the page and check out the post by "darronb", you may not get what you think you're buying.
http://www.practicalmachinist.com/ubb/ultimatebb.php/topic/30/3732.html

lazlo
05-07-2007, 12:07 PM
Before you sell the farm and spend $20-40 on a cheap grinder consider what you may be getting. Found this on the PM site the other day...

I saw that too -- I couldn't help but bust-out laughing in the middle of a business meeting :)
I guess you're supposed to store stuff inside the motor housing ;)

Here's the picture, for the link challenged:

They must have awfully small horses there in China...

http://birgenheier.com/drb/external/PM/cheap_grinder_1.jpg

pntrbl
05-07-2007, 08:39 PM
Why not rebuild the American made grinder correctly? It would still be way better than you can get today.

Why didn't I think of that? It was made by National Industrial Tools of Baldwin Park CA which is about 2 towns over from where I grew up. It's definitely got more armature than that Chiney depicted on PM. The other thing is tackwelding a bearing to a shaft belongs in the "tacky" repair category and I'd like to do better by the old hog than that.

I got a mig. Put the armature up on centers after welding? Hmmm. I know Sir John could do it but I'm not so sure about me! But, there's another project for the learning curve. This never ends .......

Meanwhile I'm gonna beam up a $40 grinder for a try. From what I learned in Harold V's posts you don't need a powerful motor to grind HSS bits. Besides that, a $40 lesson won't kill me. It's the ones in the hundreds I need to avoid.

Thanx.

SP

dp
05-07-2007, 10:26 PM
I saw that too -- I couldn't help but bust-out laughing in the middle of a business meeting :)
I guess you're supposed to store stuff inside the motor housing ;)

Here's the picture, for the link challenged:


I have an Asian combo belt/disk sander and that is the exact motor configuration. It looks like a hell of a hefty motor but you can stall it pressing a quarter's edge onto the belt. The disk is useless. It is an attractive green, though.

Carld
05-07-2007, 11:15 PM
Just press the old shaft out and make a new one and press it in. It's not that hard to do. Look at the rotor and see which way it was pressed in and press it that direction. Measure how far the end you are pushing on sticks out and press the new one in that far. What more fun than to restore a motor and use it could there be.

Don't weld it, it will warp.

Peter Sanders
05-07-2007, 11:22 PM
I got a mig. Put the armature up on centers after welding? Hmmm. I know Sir John could do it but I'm not so sure about me! But, there's another project for the learning curve. This never ends .......

Of course you can.

I repaired the front roller shaft of my lawn mower that way. I could have bought a new shaft for $40 - but these's no fun in that, besides why do I want to pay for a piece of 5/8" shaft 20" long when the one I have is only worn at the (plastic) bearing ends? Nothing wrong with the threaded end or the bracket on the other end.

Got the stick welder out, bzzzt, flash....bzzzzzzzzzzt.

Hmmm? that's about 3/4" - into the lathe brrrr,brrrr,sssssssssss. Yep that's 5/8". Into the mower -fixed :D much more fun :D

speedy
05-08-2007, 11:54 PM
I saw that too -- I couldn't help but bust-out laughing in the middle of a business meeting :)
I guess you're supposed to store stuff inside the motor housing ;)
Here's the picture, for the link challenged:

http://birgenheier.com/drb/external/PM/cheap_grinder_1.jpg

A lot of methamphetimine comes in from China. The most recent case is a 17yo "student" caught importing. I wonder how much comes in by machinery ?