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Pressing A Bench Grinder Spindle Back To Spec

Ozwelder

Active User
Active Member
#1
I have a 8" 1 HP bench grinder that had something fall on it when in storage.As a result the spindle suffered a bend about where it exits the case. Dial indicator says .012" run out.

It was a Taiwanese bench grinder but good quality for its day as it is about 30 years old and before its accident was good performer and would run on for a couple of minutes after switch off.

I can disassemble to the stage where I can put the spindle with attached rotor under a hydraulic press in vee blocks.
Is the best way to straighten the shaft or is another way recommended?

Thank you

Ozwelder
 

barnett

H-M Supporter - Premium Content
H-M Supporter-Premium
#4
I would check the point of bend with a drop of dye and a good magnifying glass....BLJHB[/QUOTE said:
Ok, maybe a noob question, but why the dye ?
 

Ozwelder

Active User
Active Member
#6
.012 inch is about the maximum I would straighten as above. Even here, I would
check the point of bend with a drop of dye and a good magnifying glass....BLJHB
Ah hah! potential cracking ! Something I should have thought about! I am fortunate to have once worked in NDT and have access to some die check and developer.

Many thanks for the replies.
 

BigWeld

Iron
Registered Member
#7
Is it possible to machine out the 0.012" and fit the stone/wheel on that side with a slightly bigger spacer?
 

FOMOGO

Active User
H-M Supporter-Premium
#8
The press should work fine. The 5 hp 3ph motor that came with the rpc I have for my mill had a bent shaft. I was able to get it almost perfect with out much effort. Mike
 

Tony Wells

Former Vice President
Staff member
Administrator
#10
I wouldn't even tear it down. Mount it securely, find a long enough piece of close fitting tubing and bend it by hand. It's already in the bearings it will run in, so better than vee blocks. Should be able to get it plenty close.
 

Lamar

Swarf
Registered Member
#11
I have a 8" 1 HP bench grinder that had something fall on it when in storage.As a result the spindle suffered a bend about where it exits the case. Dial indicator says .012" run out.

It was a Taiwanese bench grinder but good quality for its day as it is about 30 years old and before its accident was good performer and would run on for a couple of minutes after switch off.

I can disassemble to the stage where I can put the spindle with attached rotor under a hydraulic press in vee blocks.
Is the best way to straighten the shaft or is another way recommended?

Thank you

Ozwelder
There is a place in Cleveland, Tn called Flame Hardening that specializes in straightening shafts of all kinds did some work for me very reasonable
 

Ozwelder

Active User
Active Member
#12
There is a place in Cleveland, Tn called Flame Hardening that specializes in straightening shafts of all kinds did some work for me very reasonable
Thanks Lamar,
I am in Australia the shipping might be a trifle expensive.
I wouldn't even tear it down. Mount it securely, find a long enough piece of close fitting tubing and bend it by hand. It's already in the bearings it will run in, so better than vee blocks. Should be able to get it plenty close.
I believe I shall have a go at this method.
Thanks for your replies gents,
Grahame
 

intjonmiller

Active Member
Active Member
#13
I just discovered this same issue with my own. I had two, gave the nicer one (older Buffalo) to my brother because he didn't have one for his shop. Now I finally get around to mounting a grinding wheel on the remaining one (a Harbor Freight special I had only ever used for buffing, and hadn't used at all in a solid decade) and discover that the shaft is bent on the left side. Minimal vibration when I mount a wheel on the right, but terrible if I put one on the left. I haven't measured how bad it is yet, just trying to figure out how to approach the problem. Thanks to everyone for already having information for me to find. :)