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ptmachine
05-30-2011, 02:15 PM
I purchased a VOLSTRO rotary milling head recently and I have several questions. For those of you who donít know, a Volstro head is an attachment mounted in the mill (attached to the spindle) which allows you to cut arcs, radius, circles, and even angles manually. I learned to use one 20+ years ago when I was still an apprentice and it was a lot of fun!!! Now that I have my own shop I have needed one for some time and now I have one. After 20 years I still remember (roughly) how to use it!
I downloaded and printed out an instruction manual of the net and it was a help. One thing in the manual that isnít on my particular head is a zerk fitting to grease the bearings. I am assuming that my head is an older model but the weird thing is there is no model number to be found. The only number is the serial number (1995). I joined YAHOO GROUPS VOLSTRO but no one could tell me the age of my head. I did find out that the Volstro Company is out of business but I didnít find out how long theyíve been gone. One other thing I found out is the collets seem to be E25. Which I can find no information about, i.e. dimensions.
I guess the questions I am asking all of you are; can anyone tell me how old this head is? Has anyone retrofitted this head with a zerk fitting? How long has the company been out of business? Can ER25 collets be used in place of E25s? Thanks, Neal

gwilson
05-30-2011, 02:44 PM
I'd have to go get my HEAVY box down to look at the collets. I just had an epidural,too. There is a discussion on the accessories for sale dept. of Practical Machinist,where the correct collet type is discussed. Might not be on pg. 1 by now. Someone has 1 for sale.

I would impart to you the following things,though: 1. The belt power drive is totally way too fast. I never use mine. God way to break the spindle off,or a cutter off. Just crank it by hand. 2. Never use over a 3/8" cutter,and take fairly LIGHT cuts.

I have bought 3 of these Volstros. One for work,one for my helper,and a NOS one I got luckily with the collets still in their boxes.The first had the spindle broken off flush. I called Volstro and talked to the guy who made it. The spindle was $115.00 at that time. Their spindle was broken right off and the steel looked like it was too hard. Apparently the unit was brand new when it was broken. I made a new spindle WITHOUT the hole up through the middle,which I think weakened the original spindle. He said the hole was where they held the spindles to grind them. I left my spindle soft,and it never broke again. It was not a difficult job making the spindle. The units look complicated,but really aren't too bad once you open them up.

You an't be ham handed with these units. They are to be used delicately. They can make jobs a lot simpler that would be much more difficult if you were just using a rotary table.

I was also lucky enough to find an unused Volstro slotting attachment. All their stuff was very expensive to buy new.

Several years ago,maybe 10 years or more ago,they were bought out by another company,and never were allowed to make anything. I don't recall who bought them,but it was a shame. Probably,though,except for us small users,their things were obsolete,anyway,as everyone uses CNC these days.

djc
05-30-2011, 03:15 PM
One other thing I found out is the collets seem to be E25. ...Can ER25 collets be used in place of E25s?

Do you have any collets at all? If so, compare them with ER25 dimensions from Rego Fix. The other giveaway is the retaining nut thread.

If not, buy a cheap ER25 collet and try it.

If the Volstro E25 collets are the same as Schaublin E25 collets (also seen as ES25), then ER ones will fit. The only difference is that E25 have don't have the ER groove in them that snaps into the ER retaining nut (and thus makes them self-extracting). You would therefore be advised to change the nut as well.

Search the UK-branch of a well known auction site - there are nearly ten of them listed at present.

form_change
05-30-2011, 04:53 PM
I bought a second hand Volstro and found that an ER25 collet would fit but that you had to change the nut too. As I recall I think the nut was not a standard nut (that is, the thread was different) - I haven't pursued this as the purchase was one of opportunity.
There look to be at least 3 versions of the head (as the manual I have talks of a series 3 and looks different in detail to what I have). I guess refitting with a grease nipple is worthwhile if you are intending to do a lot of work with it. I'm leaving mine as is at the moment - I have more pressing things to sort out.

Michael

ptmachine
06-02-2011, 11:58 PM
I would love to change the nut and have found that the spindle is 1.25" x 12tpi. I cannot seem to find an E25 nut that is not metric. Anyone know where I might find one? Neal

form_change
06-03-2011, 04:55 PM
Yes, I was contemplating where to get a special nut like that as I leant on the corner of my lathe. It was not all that comfortable as the screw cutting levers were sticking into me at the time.
I guess if you can't buy one you'd have to get one made, but has the equipment to do that?

Michael
(Not so subtle hints contained within)

djc
06-04-2011, 02:13 AM
I would love to change the nut and have found that the spindle is 1.25" x 12tpi. I cannot seem to find an E25 nut that is not metric.

Maybe the replies were unclear. An ER25 collet will fit an E25 nut. An E25 collet will not fit an ER25 nut. The difference, and the advantage of the ER system, is the groove in the ER collet that engages the prong in the ER nut. Thus when you undo the nut, the collet is pulled from the spindle. With the E system, you can remove the nut completely and the collet and tool will stay stuck in the spindle due to friction. You then have to drift it out from the top or wiggle the tool a little to release it.