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Looking for help repairing a Wohlhaupter UPA 3 boring head

jkopel

Stainless
Joined
Apr 3, 2010
Location
Seattle, Wa USA
I picked up a 30 taper fixed shank UPA 3 on ebay for cheap since it looked messy and the seller did not bother to put the name in the listing.
It had obviously been relegated to some repeat production task as it was locked in place, and the two outer bar holder holes were entirely filled with compacted swarf glued in place with dried coolant.
I spent a long time taking it apart, but with the proper tools it all went well. :D
IMG_6912.jpg

After disassembling and very through cleaning it appears to be in OK shape and will certainly be accurate enough for my needs assuming I can
1. find repair parts
and
2. modify the shank

It is missing some of the bits that make up the feed system.
Basically the little "feed pin" on the back, and whatever goes in the hole that is meant to retain the feed pin.
IMG_6948.jpgannotated.jpg

I have the parts list and the "manual", but neither one has an exploded view showing what parts go where.
Has anyone ever taken the feed pin system apart?

I sent Wohlhaupter an email with my questions but have not heard back (it has been a week).
Perhaps a more specific email with the parts I need would get a better response.
Can you help me figure out which parts I need to order from Wohlhaupter?

Thanks, and if anyone is interested I have a bunch more photos of the inside parts.
 
Last July I needed parts for a UPA2, so I emailed to Wohlhaupter-US. It took a week or so before I got a response.

One of their Technicians emailed me the parts lists and helped me identify the parts I needed.

The parts are shipped from Germany, so it takes 1-2 weeks to get them.

If Wohlhaupter does not respond, send me a PM and I will send you the email address and phone number of the Technician that I worked with.

On the UPA2 there are 7 parts that go in those two passages.
 
Update: I just looked on Wohlhaupter's site. The phone number I have is the same one listed on their Repair Page: Wohlhaupter Corporation Repair

Factory authorized repair services are available in the U.S.
Contact Ryan Mackintosh for details.
Phone: 937.885.1878

You could try phoning them.
 
So not only does Wholhaupter make great boring heads, they also have very good customer service.
I heard back from them and within an hour had an updated parts list that let me figure out what I needed.
I also got a quote for parts shipped from Germany that seemed totally reasonable given the quality and precision of the tool.
Not sure yet what shipping will be, but all in all a very good experience dealing with them!
 
I picked up a 30 taper fixed shank UPA 3 on ebay for cheap since it looked messy and the seller did not bother to put the name in the listing.
It had obviously been relegated to some repeat production task as it was locked in place, and the two outer bar holder holes were entirely filled with compacted swarf glued in place with dried coolant.
I spent a long time taking it apart, but with the proper tools it all went well. :D

137713d1429755662t-looking-help-repairing-wohlhaupter-upa-3-boring-head-img_6912.jpg


Love the photo and description of the secret, rarely published and highly technical set of precision factory tools. I do think you forgot the obscure, but always recommended, acetylene wrench. :D
 
After disassembling and very through cleaning it appears to be in OK shape and will certainly be accurate enough for my needs assuming I can
1. find repair parts
and
2. modify the shank

It looks like you have point 1 sorted. Good news regarding point 2 as yours has a removable arbour so you can just turn up a new one.
 
Stephen
I am glad someone else finally recognized the value of good precision tools. I was starting to become concerned.

Peter
It is s fixed shank unit unfortunately.
I am hoping it is just case hardened, but I may have to have it ground.
 
Peter
It is s fixed shank unit unfortunately.
I am hoping it is just case hardened, but I may have to have it ground.

Are you certain about that? The later model heads with a red dot on them are all removable shank as far as I'm aware. They use a differential thread system.
 
Quite certain, the removable shank models have a differential screw inside the shank, and this one does not. However I could try grabbing it in the vice grips and hitting it with that puny hammer, or getting out Stephen's acetylene wrench... [emoji6]
 
Wow, almost 2 years later but I finally finished repairing this thing.
The shank was hard, but not all the way through so even with my puny tools I was able to get it turned down to 3/4" to fit a collet.

I thought I would take a bunch of pictures of the reassembly to help anyone else who treads this path.
The first set is from two years ago when I cleaned the gear ring. I don't actually remember much detail for the task, but maybe the pictures will help someone.

IMG_6897.jpgIMG_6898.jpgIMG_6899.jpgIMG_6900.jpgIMG_6901.jpg

More to follow.
 
Gear ring part 2

IMG_6902.jpgIMG_6903.jpgIMG_6904.jpgIMG_6905.jpgIMG_6906.jpg

About all I remember is that there were LOTS of tiny balls in there that had to be cleaned in solvent and then stuck in place with new grease. The Wohlhaupter manual recommends Lithium grease for this part (lithium saponified multi-purpose grease, DIN specification KTA 2 K-DIN 51825with the following physical specifications:Pour point 195°C/consistency No. 2/
operating temperature- 35°C to maximum+ 135°)

For some reason I stopped taking pictures at this point (maybe my hands were covered with grease) so this is the end of the ring reassembly.
Detail on the rest of the head is next.
 
Last edited:
head internals 1

This is all assuming that like me you have taken every last little part out to clean off the 20 year accumulation of dried coolant. I used a light way oil on everything during assembly.

1. Don't forget the tiny hardened washer that fits under the advance gear.
IMG_9111.jpg
2. Drop in the bottom half of the advance gear set.
IMG_9112.jpgIMG_9113.jpg
3. Put the main worm gear in place. You will have to be able to wiggle it around for the next part so it is easier if you don't put in the shaft yet.
IMG_9114.jpg

More to follow...
 
4. Drop in the top half of the advance gear set and rotate it until the dog clutch teeth lock together. Then turn the main worm gear to let it settle down all the way on the shaft.
IMG_9115.jpgIMG_9116.jpg
5. Now push in the long shaft that the main worm gear runs on. Insert it rounded end first, and I found it fit much better from one end.
IMG_9117.jpg
6. Now put the gear cover back on.
IMG_9118.jpg

More to come (tomorrow).
 
Dian
I just reread the manual and I think you are right.
Fortunately it is easy enough to pull the top off, wash out the oil, and pack some in there.
At least not having grease all over everything makes the pictures clearer...

To continue, now the real fiddly bits begin.

7. The "feed lever" is this little complicated tapered part. It couples the feed button to a tiny pin on shaft and locks the gear ring into "advance mode". It needs to drop down into a hole in the head so that the pointiest part is up, and the flat on one side of the bottom is facing out. You can check that it is correct by looking in the oval hole on the shaft to see that the flat is facing out.
IMG_9120.jpgIMG_9121.jpgIMG_9137.jpg

8. Next is the feed button itself. It has two notches that need to end up facing to the upper left when you are holding the head shaft down and facing you. It also has a flat on the end that needs to be rotated down so it can pass of the top of the lever you just put in. You put it in the lower of the two holes and then rotate it so it engages the lever and (you think) the notches are in the right place. You can tell if it has engaged the lever because you won't be able to just pull it out (took me forever to figure this one out when I was taking it apart).
IMG_9124.jpgIMG_9125.jpg
 
feed sensitivity adjustment

9. The feed button is supposed to pop out automatically when the head reaches a set stop point. The amount of force it takes to do this is set with the next bunch of parts. If you are holding the head shaft down and looking at the feed button there is a threaded hole on the left side. These parts go in that angled hole and are pushed down against the feed button. There is a double angled pin that goes in first, then the spring then the stop pad then the screw (I had to make a screw so your will be different).
IMG_9126.jpgIMG_9127.jpgIMG_9128.jpgIMG_9129.jpgIMG_9131.jpg

More later.
 
Gear ring install

Next up is putting on the gear ring.

10. put the gear ring lock pin into the hole on the bottom (or top?) of the head.
IMG_9132.jpg

11. Put the tiny hard to grab easy to drop pin into the slot on the shaft. A bit of grease is helpful here to hold it in place.
IMG_9136.jpg

12. Put on the gear ring and rotate it gently until it drops into place on the advance gear. Put on the "closing" ring and the snap ring, make sure the snap ring captures the pin on the closing ring. This is an integral shank unit, and I know the removable shank heads are a bit different.
IMG_9133.jpgIMG_9134.jpg
 
Gib and lock screw.

13. Lubricate all sliding surfaces. Gently slide the bar holder into the dovetail. I found that if I pulled it up as far as I could I could gently rock it over the worm gear until the teeth on the rack engaged the worm.

14. Push in the gib.

15. The next (and last) complicated part is the slide lock screw. There is a pin that is angled on both ends. I did not measure, but it does not look symmetrical to me. I picked the end that seems to match the dovetail angle the best and put it in that way.
IMG_9138.jpg

16. There is a tiny 3mm ball that drops into the hole next. This bears on the back of the angled pin and the top of the ring lock pin (step 10) and locks bot the slide and the ring gear at the same time. Clever those Germans...
IMG_9135.jpg
17. There is an equally tiny spring and pin that go into a hole next to the lock screw hole. The lock screw SHOULD have a little pin in one of the holes around the center that hits this sprung pin to stop you from accidentally backing the screw out and loosing the ball. I had to replace the pin in the lock screw since someone had sheared it off. You basically put in the spring, then the pin, then hold the pin into the hole while you tighten the lock screw down. Once the lock bottoms out you release the pin and make sure you can back off enough to free the slide before the screw hits the stop. If you can't then you have to knock out the stop pin and move it to the next hole.
IMG_9139.jpgIMG_9140.jpg

At this point everything else is pretty straight forward so I stopped taking pictures.
I am super impressed with the quality of this thing, and am looking forward to using it.

I have one picture left for this post, so here is what it looked like when I got it :rolleyes5:

DSCN4795.jpg
 








 
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