[How-To] Harig Grind All #1 Disassembly and adjustment

[dkemppai]

Good point....I'm no expert and this is my first experience with one of these. The plate on top is a Harig plate. Pic attached.
It appears factory and of good quality but now...Hummmm?
Thanks for that...you just added another thin spot to my scalp..LOL
Thank you..

I did look quick, looks like the brand new ones are green. You probably have a real harig.

Thinking about this, it is possible there is a shim missing, or something similar somewhere? Maybe someone disassembled and didn't properly reassemble???

 

[kenpo11]

Great idea!
Now that would explain a few things. Thats a possibility for sure. Thats another avenue to follow. I took it apart 4 times total and ground the back race down with .0002 each time. It is now within .0004 on runout. But.....we have found yet another snake in the wood pile. I can adjust the V-block up and down within tenths of center...BUT, now there is .0015 error at 90° high and low on the sides of the V-Block when it's spun sideways. High on one side at 90° and low on other side at 180°. Which seems to suggest your theory. Possible there could be a shim missing? Theres no evidence on the V-block to suggest enough wear to account for a Rockwell hardened V-block to be that far out of center.
Don't have a parts manual to check for shims...I did call Harig to order the fine adjustment screw for the V-block...A new V-block....$400.00.
Not happening...May just try to braze a thin layer of material on the low side and lap it down gently until it reaches tolerance, unless there is a shim missing.
Thanks for your suggestion...I will definately pursue that theory.

 

[dkemppai]

That's a lot of error at the 90 degree positions! Are you measuring the faces of the v blocks, or are you checking against a pin held in the v block? It's possible the v is correct, but the edges are off.

Just recently I purchased one of the import knockoffs of the harig. I can't measure the +/-90 degree error against a pin in the v blocks. (Never did check the sides of the v block. Didn't even consider it...) Actually, the less than a tenth out of round I can see, I think is from the end mill I'm using as a pin. I really need a better pin to check against.

Hopefully it's something simple that you find!

Dan

 

[kenpo11]

I placed a 1/2" carbide roller in the block and indicated off of that. I also checked the block on surface plate for square...it appears the edges or One side may be off. I did use a .001 brass shim stock to shim one side if the block....improved the runout but it's definately off .0015. ...003 total. Back to head scratching...
Thanks for the reply...I can always use another brain cell to pick.. LOL
Much appreciated..

 

[ddickey]

Just recently I purchased one of the import knockoffs of the harig. I can't measure the +/-90 degree error against a pin in the v blocks. (Never did check the sides of the v block. Didn't even consider it...) Actually, the less than a tenth out of round I can see, I think is from the end mill I'm using as a pin. I really need a better pin to check against.


Dan

What and where did you buy?

 

[dkemppai]

I placed a 1/2" carbide roller in the block and indicated off of that. I also checked the block on surface plate for square...it appears the edges or One side may be off. I did use a .001 brass shim stock to shim one side if the block....improved the runout but it's definately off .0015. ...003 total. Back to head scratching...
Thanks for the reply...I can always use another brain cell to pick.. LOL
Much appreciated..

Hmmm, that really weird. Wonder if it was crashed hard enough to move things that much.

If you have some length to the pin, is the runout the same at the end of the v, and 1 or 2 inches out from the v? That is, is the vee block tipped up or down in the +/-90 positions?

It's a bummer this thing is off that far.

 

[dkemppai]

What and where did you buy?

Just one of the little higher dollar imports from ebay. There used to be a whole batch in the $400 range that looked good. Then a whole pile of inferior looking ones showed up for $300 or so. Decided to grab one of the last ones that looked better.

And basically, I think I got really really lucky. Few minor gripes about it, but overall mechanically WAY better than expected.

Look for ones missing a tag. Mine showed up with a tag, with the center height marked to .001mm. The newer batch only shows .01mm center height resolution. I think that's an indication of the "quality".

Would have loved to have a Harig, and someday might. But for now this will do...

 

[kenpo11]

As far as the runout goes...It does progress the further out you go. Quite rapidly also. 1/2" from end=.0005... 1" = .0015. V-block seems to have some serious issues.
For what I do and since I don't work as head forman machinist at NASA anymore....(just kidding). My tolerances don't require total .0000000001 accuracy. Home shop tolerances are adequate. Although it would be nice to put a round rod in and have a dead center come out instead of a Harley camshaft. I found this unit on Facebook marketplace for....wait for it....$125.00.... Now the "BUT"....I had to travel 3 states, 366 miles and 6 hours to fetch it. All in all I think it's salvagable and if nothing else, a learning guide and possibly useful to help someone else with. Hence the posting here. I'm also one to buy the imports from ebay usually. And I think it makes us a better "Chinist" when we can fix anything....certainly a China tool. Put that on your next resume.
The V-block is the problem now. I have resolved the bearing slop by grinding the back race to acceptable tolerance for my needs and it wasn't Rocket science either. Now the V-block..?? Since I'm not going to Tig it and try to grind it back to tolerance...I think a good coat of brazing rod aided by some milling, honing, lapping, and stoning might set the block back in order...$400 is out of the question.
Who would spend $125 for a Grind All and doll it up with a $400 V-block? LOL
Thank you all for the input and replys. This is just another project to learn on and peak my skills. Hope it's useful to someone else as well.
Stay tuned..

 

[kenpo11]

Just one of the little higher dollar imports from ebay. There used to be a whole batch in the $400 range that looked good. Then a whole pile of inferior looking ones showed up for $300 or so. Decided to grab one of the last ones that looked better.

And basically, I think I got really really lucky. Few minor gripes about it, but overall mechanically WAY better than expected.

Look for ones missing a tag. Mine showed up with a tag, with the center height marked to .001mm. The newer batch only shows .01mm center height resolution. I think that's an indication of the "quality".

Would have loved to have a Harig, and someday might. But for now this will do...

I got lucky....(I hope) with the Harig. Time and grinding dust will tell. LOL. I spend hours a week searching ebay for deals on tools. Some have been treasures while others....not so much. But hey, if we weren't spending money on ebay buying import tooling, what else would we be doing with it?
Thanks for the reply...

 

[kenpo11]

Heres where I would appreciate some opinions and advice before I go and create a very expensive paper weight, i'm hoping someone can give some advice here.
As far as the preload on the bearings, I feel good about resolving that issue within acceptable tolerances..and saving BIG $$'s not sending it in for repair to the Harig god's.
After everything I've found so far, I can now say the problem had to be caused by bad driving. Maybe not a DUI, but someone must have crashed this unit. As earlier I showed the V-block had broken teeth, missing fine adjustment screw (on order) and no stop clamps. I'm attaching more pics to show the V-block inspection I did. I used an angle block I ground and squared to within .0002 of square. I used a magnetic cylinder square (checked for square) I placed the mag cylinder square on the Angle plate vertically. Then the V-block was clamped to the Mag Square with a clamp and brass shim stock.
Looking at the attached pic's, you will see I checked the chuck groove that the v-block rides in for wear and parellelism. All was good with 1.534 parellelism at each end. Next the V-block was checked and it measured 1.5318 and 1.5321 at each end. .0003 diff.
Placing the V-block on the surface plate and indicating it showed some problems. Here is where some input would be appreciated. There is perfect flatness on one side of the V-block on the mating surface. The side with the grooves for the adjustment are off .0015 lower laterally from the opposite side of block previously measured. Then it has a slope from the beginning of the teeth to the end of the teeth of .0005
So now the question is Remedy?
Should I (A)..grind the complete back of the V-block with the mating surface containing the fine adjustment teeth..Therefore removing them and eliminating the fine screw adjustment....Or
(B)..Just try to resurface the opposite side of the block bringing it into specs matching the fine adjustment teeth and therefore saving the adjustment.
Not that I couldn't live with just gently tapping the block into alignment when a job calls for it and doing away with the fine adjustment screw. It would be like doing away with power steering on your car..no worries right?
A new $400 V-block is a No-Go-No.
Thanks for any advice..
Pics attached..