• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
[4]

Pressing A Bench Grinder Spindle Back To Spec

[10] Like what you see?
Click here to donate to this forum and upgrade your account!

Ozwelder

Active User
Active Member
Joined
Oct 15, 2011
Messages
152
Likes
30
#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
 

The Liberal Arts Garage

Active User
H-M Supporter-Premium Member
Joined
Sep 4, 2013
Messages
479
Likes
120
#3
.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
 

barnett

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Mar 14, 2014
Messages
132
Likes
104
#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 ?
 

The Liberal Arts Garage

Active User
H-M Supporter-Premium Member
Joined
Sep 4, 2013
Messages
479
Likes
120
#5
If a stress crack is starting ( very dangerous! ) the dye will seep into
the crack and make it more visible.......BLJHB
 

Ozwelder

Active User
Active Member
Joined
Oct 15, 2011
Messages
152
Likes
30
#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
Joined
Mar 17, 2014
Messages
6
Likes
1
#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 Member
Joined
Sep 2, 2013
Messages
1,477
Likes
1,198
#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
 

The Liberal Arts Garage

Active User
H-M Supporter-Premium Member
Joined
Sep 4, 2013
Messages
479
Likes
120
#9
Is it possible to machine out the 0.012" and fit the stone/wheel on that side with a slightly bigger spacer?
Trim to "straight"shrink on a thin sleeve ( wheel andwashers length,true up threads)
Get experienced help on site....... BLJHB
 

Tony Wells

Former Vice President
Staff member
Administrator
Joined
Jan 22, 2011
Messages
6,883
Likes
1,919
#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

Iron
Registered Member
Joined
Dec 25, 2014
Messages
5
Likes
1
#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
Joined
Oct 15, 2011
Messages
152
Likes
30
#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
Joined
Apr 21, 2015
Messages
900
Likes
681
#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. :)
 

The Liberal Arts Garage

Active User
H-M Supporter-Premium Member
Joined
Sep 4, 2013
Messages
479
Likes
120
#14
I discussed this problem (with others adding more good thoughts) some time ago
See if you can call back that thread......BLJHB
 
[6]
[5] [7]