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Abene vhf-3 just landed in my garage - VFD ok on feed motor?

Wazic

Plastic
Joined
Apr 9, 2013
Location
NY, USA
Greetings,

New forum member with an Abene vhf-3, ser#3803, in central ny. The mill is in ok shape, but missing the overarm support and a proper drawbar. The drawbar turned out to be a piece of threaded rod. Cauls on the face of the spindle are a little dinged up, I suppose from not having the eject feature of a proper drawbar. I needed to "extract" the CAT40 tool holder firmly wedged in it (not fun). I imagine I will do a proper teardown once I have some kind of a gantry crane. I have a friend in Sweden poking around about parts, but I am not holding my breath. I have someone on the prowl for a quill head, but fully realize its like dreaming of the lottery. There was no coolant pump, but I have one that fits ok. I did make out pretty well with a box of nmtb 40 tooling. It made the price I paid sting a little less.

Other than advice on a source for parts (other than Abene), I have a question on whether or not a VFD makes sense for the feed motor. I have a 7.5hp RPC which should squeak by for the spindle motor, but was wondering if there is something to be gained by using a VFD for the feed motor. I'd need a VFD that reverses for the rapids (and rewire/bypass the switches/relays), but other than that, do you guys see a problem with that?

I'll take pictures soon,

Thanks,
W
 
Out of curiosity, what is your motivation for the VFD? Is it to gain variable speed or is it because you want to use the VFD as a phase converter? If the latter, then I see no issues at all. If you are trying to use it to gain variable speed, then there are a few considerations. First, if the feed motor has an integral fan, then at low speeds you may not be drawing in enough air to properly cool the motor. That is a problem. And on the opposite spectrum, high speeds result in a very fast dv/dt that can break down the insulation of the motors if they were not made to work with a VFD. You'll get minute arcs that will slowly grow to bigger arcs, and eventually a failed motor. Remember, these machines are all pretty old, manufactured well before the advent of the VFD. But, if you exercise some decent caution, then there is no reason why you cannot use a VFD. Just my 2 cents. :)

Alan
 
Greetings,

The drawbar turned out to be a piece of threaded rod. I suppose from not having the eject feature of a proper drawbar.

There are plenty of mills that were built without any "eject" feature.....with nothing more complicated than a rod with threads at the holder en

I needed to "extract" the CAT40 tool holder firmly wedged in it (not fun).

Removing the holder should be simple and painless. With the draw bar threaded into the holder (threaded rod) loosen the bar about two turns.
Strike the end (away from the holder) smartly with a hammer (i use copper). This will break the taper loose. Then simply undo the rod and your done...
Should be like zero drama or effort....

I'll take pictures soon,

Thanks

Looking forward to the pictures....
Cheers Ross
 
so would yours be made around 1967 or 8? mine is serial number 3650 and it was made in 1966. please put up some pics!
 
Toolholder removal

There are plenty of mills that were built without any "eject" feature.....with nothing more complicated than a rod with threads at the holder en


hi,
yes, the issue at hand was that the taper on the tool holder was pretty beat up (galled). my heart sank when it came out, but i calmed down when i could get light shined in the taper. it must be the steel on the receiver is harder than the tool holder (luckily). whenever you see stuff like this, you wonder how the rest of the machine was cared for. i am crossing my fingers. i think the toolholder was also in the head for a looong time, and was happy to stay there.

cheers,

w
 
ll pretty old, manufactured well before the advent of the VFD. But, if you exercise some decent caution, then there is no reason why you cannot use a VFD.

yes, the insulation breakdown issue was rattling around my brain. yes as a converter, and maybe speed control, though the gearing gives a good range of speeds as is. when i get a chance to pull the motor, i can check out the windings for real. thanks for the input
w
 
hi,
yes, the issue at hand was that the taper on the tool holder was pretty beat up (galled).

w

Look into getting a "spinLmate"
Its a tool used to clean the taper when doing a tool change. I have one and use it all the time.
It comes with standard cleaning (soft) blades to keep the chips cleared.
However you can also purchase lightly abrasive blades that fit into the base tool> These are designed to remove varnish and corrosion.....
A light application with the varnish removers will do wonders to shine up the machines taper....

Cheers Ross
 
You dont need to worry about arcing as long as you keep the cables short. It will work just fine. I have all my machines with VFD's including my SN 481 Abene VHF fro WW2. What i would do is that i connect the motor wires to the vfd then i put small relays for the logic. Typically you can connect the relay coil over the contactor coil. That way you maintain all functions and it is easy to revert.

I just did this on my covel 512 grinder. Spindle and coolant both run off vfd's

You dont want to put any brakers between vfd and motor.

Ulf
 
I'm no expert on phase converters but given your responses why put a VFD on the feeds? you seem OK with the built in range. The spindle is supposed to be 5hp and feeds 2hp. I'm no expert on phase converters but from my non-existant experience and asking around it seems that a 7.5 rotary converter should power both? None of these should be starting against a large load like a big compressor, if your using rapids either your spindle is off or its just another idler? Under load may be different, but in all probability I won't be pushing its material removal limits.

What am I missing - part of the reason I ask is I have a VHF3 as well, and picked up a 7.5 motor to use for a phase converter (that needs to be built), and I'm hoping I don't need to add another small idler.

Paul
 
couple of thoughts about parts: there are none but for the factory. i had good luck dealing with a guy named Fredrik Yman at the Abene factory. he's a service rep but can place orders for you. just about everything for your machine is available, and the prices while not cheap are not astronomical either. takes some time to get the parts delivered: for small things a couple of weeks; for my drill quill head it took a full 2 months. And the current drill quill head will fit your machine. but not everything matches up with the new head; for example the pin to hold the head at 90 degrees is rendered useless as well as the rear hold down when laying flat. I've modified the rear one so that it rests exactly flat, but since i haven't used the machine yet i don't know how much stability is lost, if any, by not having the pin hold the head at 90 degrees. i may try to build a holder of some sort later.

BTW, if your old head is buggered up i have an old one without the quill in good shape i'd consider selling.
 
Thanks for the collective wisdom - I will try and run both motors first, off the RPC as is, just good to know and be ready if I need to order a VFD. I have to admit to being a bit of an electro-geek, so the VFD was as much gadgetry curiosity as practical. I often listen to the cutter, and run the feed motor like a bike throttle (on the bridgeport), adapting to the material. I am hoping that the set gear, and step back in front method feels ok. Most of my work is designing heat sinks and cooling plates in aluminum, for very high power amplifiers and LED's.

I will definitely be in touch if the head is buggered up - thanks

Finally posting pictures;
IMG_6339.jpgIMG_6341.jpg
 
Looks nice - my question is what is the shaft hanging out from the right side of the head support casting - in front of the belt cover???? Never seen that on any others, maybe an addition by a PO to hang something on?

For grins there is currently one on ebay (VHF3) of the "there I fixed it!" variety. It has a Chinese version of a servo table drive hung on the end of the table:ack2:, someone figured it was easier to add that than fix it - who knows what else is buggered up, all for the amazing low price of $2750 or make an offer:nutter:
Paul
 
I will definitely be in touch if the head is buggered up - thanks

Folks have had success re-cutting the tapers on machine spindles in place ....
Search the general and CNC forum .

There is also a member that does professional spindle regrinding on the machine...
believe he is :"Walt @ SGS"

Cheers Ross
 
i have the same question PaulM has about the shaft extending out from the right side head casting. The black oxide cover here is a is an oil block for one of the main transmission shafts for the spindle; curious to know if the extended shaft spins with the transmission shaft or is stationary. Nice machine.
 
Abene extra shaft

curious to know if the extended shaft spins with the transmission shaft or is stationary

the shaft rotates with the spindle - i didn't take notice when the mill was under power whether it was rotating at the same speed - i wrongly thought at the sellers shop that it was the "jog" shaft for getting the mill in gear, not knowing the knurled hand wheel was further to the right - it took me a while to figure out its "extra" - i will know more when i get back home (been away with work for weeks) and get it on the newly set up RPC - can't imagine what its for... maybe a power take off for the second head i mount on the overarm, hmmm....

cheers,

w
 








 
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