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Abene VHF3 1963 - Dissassembly

rosteri

Plastic
Joined
Dec 2, 2019
Hi!

This is my first post, but I've been reading for many years and thanks to this forum and the few excellent restoration threads I ended up with an Abene as the proud second owner - it was used from new in a one man precision shop in Södertälje/Stockholm and it certainly has seen some action, but also a well documented service, as it must have been a big investment for a young machinist at the time. I've now owned it for some years.

My Abene developed recently the knee leak and now that all my oil is in the coolant sump I have to do something about it. The table removal was straightforward and the wear is very even and identical on both sides. The scraping was still nicely visible in the center of the saddle, but worn out towards the ends. But now I'm stuck with the telescopic chip guards. My machine has them fixed very elegantly with a negative V at side of the telescopic cavity, so I can't lift them upwards out of the way. They have also some chips jammed in-between, so they move really hard back and forth - The Y movement was not very good, so this is the culprit and I definitely need to get them off and clean. The chip guard plates have also coolant grooves built in them and there is also a drain channel to the front of the machine. This was a fairly sophisticated set-up and these details seem a lot simpler in the pictures of newer machines.

But, thanks to this setup I need to remove the small gearbox out of the way next, as the chip guards are one piece and they slide only outwards / towards the front. The gearbox now hangs in place with a drive shaft and the lead screw.

So my question would be - do I need to remove the side gearbox to release the saddle gearbox shafts and the lead screw? Peeking thru my small opening I don't see an alternative, as the sprockets of the side gearbox seem to be in the way for the shafts to slide towards the front.

With winterly greetings from Helsinki, Rosteri

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Thanks! I have seen your post and I did plan to do the famous "Dovel pin turn - pull maneuver" - thanks for sharing your findings, information like this is really essential as none of us have former experience from service or assembly of these machines.
 
Out of curiosity, what year is your machine? I notice the switches are located up on the side rather than under table on X- side, as well as the coolant pump location difference and the missing 2 large cap/plugs on the front lower casting. Mine is a 1970 model. Nice clean machine you have!
 
Thanks! The machine is a 1963 - the machine has nice chip guards around the table and the original owner has raised the switches so they can be operated with the chip guard. I'll see if I can find a picture showing it.

I'm still stuck with the dovel pin removal to rotate the transmission, it is hardened - very hard - so no drill / threading to pull it out. I'll need to push it out from the inside, but I have very limited access. A special tool next...
 
I think my doowel was drilled and tapped already.
Maybe there is another way where you remove the gears from working inside the knee. If something comes to me I'll let you know.
 
There are commercially made dowel pullers that could be replicated.
Here are the basics:
There is a collet (different sized bores for different OD dowels)
The collet has a tapered OD at the end where its bored for the dowel. Collet is slit to allow it to collapse.
The body of the collet is drilled and tapped
There is a sleeve that slides over the collet. The sleeve has a mating taper at one end. The opposite end is closed off with a hole in the center.
Collet fits into the sleeve and the shaft of a slide hammer it threaded into the collet.
A jam nut on the slide hammer shaft is tightened against the end of the sleeve pulling up the collet which closes on your dowel.
A few wacks on the slide hammer and your dowel is out....(in theory)

I also have a pair of good "Vise Grips" with a nut TIG welded to the handle to allow my slide hammer to be threaded to the handle in such a way that the hammer is parallel to the long axis of the "Vise Grips".
That works for pulling lots of pressed in parts.....Could use a Dremel to grind a radius into the Vise Grip jaws to give better contact to your dowel.....

Tig weld thick washer to the end of your dowel and use a bar or slide hammer to pull/lever it out...grind the washer off once removed....

Cheers Ross
 
Fantastic, thanks to both - I've been working on the pin today from the inside (with no luck) and looking quite a bit at the spare part drawings, so at least I'm very familiar now how it all works.

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It would need to be quite a supertool to grip it from the outside, but Ross the TIG proposal was great - would have never crossed my mind... I'll try that tomorrow!

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Yes not much pin there to grip....
The plus thing about the weld is that the heat going into the pin will often stretch the surrounding material and when things get dead cool the fit on the pin could be eased a bit to make removal easier...
Be sure to remove the plating from that washer before welding....

If you can't get under the washer to wedge it up and pull the pin, then weld a nut to the washer that you can couple to a slide hammer....
Cheers Ross
 
Well, that was a 5 min job - I was prepared to weld a nut onto the washer, but a lever was enough to pry it out. Funny how welding on a milling machine never even computed in my head as a possibility. Thanks!


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Nice, now check the inner end of that dowel to see if it was in backwards. Rotate the gearbox CCW until the you can turn the handwheel without back-driving the gearbox (feed needs to be engaged I think). Once it is free you will be sure you can pull out the gearbox without the gear teeth breaking.
 
This thing is quite a puzzle. Inside my mill the pushrods are connected to the gearbox with C lockrings, so I've been scratching my head how the gearbox would come out without detaching the pushrods first.

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When I started looking at the Abene manuals also this detail was changed after the first series of machines (#3013-#3557), so this will be a good note to all future people working on this early series - the dissassembly sequence is different. In the newer machines the pushrods can remain in place. Kudos to Abene for being able to make things quite a bit easier without changing the basic concept and layout.

So back to the hard way. I can't remove the pushrods, as the two shafts and gears for the Y-axis are in the way. So they will need to be removed first. Of course the hand wheels are different in this first series and to top it off the the detail of the Y-axis handwheel is strangely missing in the spare part manual. After some fun with a tapered dovel pin and a few mysteries the handwheel and micrometer scale is now off. Next up is an interesting threaded lock, which should secure the first bearing. The bearing housing is threaded to the body, but there is no detail to grip it - thanks Abene...

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The VHF-2B seems to have the same details, so I'll need to do a search on it.
 
The disassembly sequence that I finally came up with is the following:

- Remove table and saddle
- Remove Y hand wheel mechanism and bearing housing of the leadscrew. The dovel pin is tapered
- Remove Y driveshaft, it has an M5 thread at the end and can be pulled out with it. The gear (keyed) at the end can be tapped off once the shaft is pulled outwards. The coin slotted cover is tricky and I didn't manage to open it as is
- The leadscrew can't be removed unless the end bearing has a loose fit (the gearbox is in the way to move it)
- Now there is access to remove the two C lockrings from the lever pushrods. Very hard to reach
- Remove knee gearbox dovel pin
- Thread the gearbox mounting bolt holes with a 10 mm end tap so you can use them to pull out the box - the hole is 9 mm, but it still works. I ground the end of a 10x1.5 mm tap flat to reach the bottom / where the 8mm thread starts. If you have 10x1.25 mm bolts and tap then they would be a better fit
- Push out the gearbox 1-2 mm with 10 mm bolts to ensure it is released and spray some penetrating oil. If you move it more out then you damage the knee gear, as cwilcox found out.
- Turn the 10 mm bolts out half a turn and use pry bars on the 10 mm bolts to rotate the gearbox anti-clockwise so the dovel pin hole just dissappears. The knee gear should be now disconnected from the gearbox.
- Pull out the gearbox

Next:
- Pull out the y lead screw
- Remove chipguards (finally...)
- Leg removal

Note: I added quite a few pictures as a future reference, as at least I couldn't find these details anywhere for the early Abene VHF3 (and VHF2) versions.

I used the plunger holes to unthread the bearing housing:

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I tried to open the coin slot with a washer in a large socket - I gave up after 4 bent washers and welded a nut to it.
 

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The Y leadscrew was very tight on the bearing and a simple puller set-up was needed to get it out - pushing it back in place will be fun.

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The knee doesn't have good points to lift it, so I made a quick tool to help out.

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Ok, the leg is finally off... I'm gradually reaching the point where I can start the repair.

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I did an oil change recently (well a couple of years ago) and with the knee so full of chips I must have moved a few of them into the leg during the process and scratched it, as it started leaking shortly after.

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Any suggestions for the best way to permanently repair the scratches?
 
I had scratches like that in mine and I filled them with epoxy jb-weld and it is holding oil (with new o-rings).
 








 
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