# Volstro Rotary Milling Head



## MachineTom (Jan 18, 2012)

I've owned a Volstro Rotary Head for 5 years but only once used it. For those that are unfamilar with a rotary head, it is a unit that mounts to the quill, and can turn like a rotart table 360°, as well as have a crosslide with 3" of travel, that sets the radius as well as provide crossfeed in which ever angle it is pointing. A great thing to have in a non CNC shop, as they all used to be.

 The issue for me was the mounting of the beast. You had to remove the power drawbar and install an extra long drawbar, then mount the head, while lining up the collet drawbar and spindle. Since I retired no extra guys around to do the ladder work. So the Volstro sits in the box, until yesterday. In thinking about what was needed to make the mounting easier, I came up with this idea, remove the R-8 drive shaft and make a two piece unit to replace it. One piece to mount in the spindle, and a mating drive piece that stays in the Volstro Head. 

This is a shot of the two piece drive (foreground) and the orginal in the rear.







For the spindle collet piece I cut a end mill holder at the end of the taper, milled a 5/8 notch and bored a .750 hole, for the driven piece a piece of O-2 was machined with a .750 stub, and a mating 5/8 notch. This shaft goes through a double bearing and a bevel gear is attached to the end. 

After reassembly of the head here it is mounted to the BP ready to go. It does take up quite a bit of vertical, but its not like its always on there. This unit has the pulleys that mount in placed of the fine feed wheel, and that provides power feed for the rotary function, as well there is a crank handle that plugs in.






I have some arced plates to mill for the Corliss project and this is the tool to do it. 

Thanks for looking.


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## rklopp (Jan 19, 2012)

My favorite instrument maker at my prior employer used one of these to make almost everything I designed. He was a wizard with a Volstro. Of course CNC has rendered them obsolete.


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## MachineTom (Jan 21, 2012)

The two piece drive shaft modification seems to work fine. There is a right angle drive unit sitting in the closet that will get the same treatment soon. I guessed that were more BP owners on the forum, guess I was wrong.


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## pete (Jan 21, 2012)

Tom,
Mines not a actual Bridgeport but Taiwan and classed as a 3/4 sized Bridgeport clone. The head, spindle size is the same as the Bridgeport specs so your idea is one I've filed away. I'll get some future use of this so many thanks. 

Nice Volstro unit. I'd love to have one since CNC isn't in my future. Volstro made some expensive and top quality equipment and I wish they were still around. I missed out on ordering a Volstro slotting head by about 6 months since I didn't know they were closeing shop. They made more than a few very desireable accessories for Bridgeport type mills.

Pete


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## MachineTom (Jan 27, 2012)

Well I took out the R/A head for the BP, and did the same modification to the drive shaft. Heres what it looks like in the full horizontal milling setup. It took 45 minutes or so to install it the first time, hoping I can get better at it than that. Years ago when Ebay was good I bought a bunch of cutters for the 1" arbor. Often paying a couple bucks each in good size lots. NO more do you find that its mostly BIN and $$.


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## kvom (Jan 27, 2012)

The RA head can also be use as a horizontal drill, perfect for putting holes in the end of long work pieces. I could have used one of those a few times recently.


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## MachineTom (Jan 28, 2012)

Yes it does, there is a cannon project that will be done just that way, as soon as I complete the coolant system for the drilling.


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## justintime (Jun 18, 2015)

In case this post is still being read,   I have the Volstro Rotary unit and need a couple missing collets. I would really love to know just what the actual collet designation is,  if anyone out there might know ?  The collets I am missing are 1/4" and 5/16"; also 7/16" if there is such a thing. 

Thank you very much in advance for any information that follows !
Darryl Dodge aka"justintime"


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## MachineTom (Jul 22, 2015)

The collects are a std type, just google collet dimension, and you can figure them out. The max size is 1/2" 
But I only use that size when in drill, an end mill that size would likely kill the gear sets, they are not very big.


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## Blogwitch (Jul 22, 2015)

Tom,

I am like Pete above, having a 3/4 sized Bridgeport clone, a Chester 836.

I bought my RA head without knowing it would fit correctly.

It fitted the quill size OK, but the angles and width for holding the support casting for the horizontal arbor were incorrect for my machine.

But a little bit of work soon had everything working great.

http://chestermachinetools.forumchitchat.com/post/horizontal-milling-with-my-%C2-%A3-7282781?pid=1286071794#post1286071794

Not only is the RA head good for drilling but also for boring long lengths that can't be held upright and for pocket milling on the end of long items, again that can't be upright. I also use the RA head for cutting finning using ganged slitting saws.






It really is an attachment that is used a fair amount. I don't use the horizontal arbor much, but the RA head gets used a fair amount, and they can be bought fairly cheaply from new.

John


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## justintime (Jul 24, 2015)

The collets are an "E" type and swiss made machines are all I have found that use them besides Volstro Rotary.  They do not match any charts or offerings from collet makers spec sheets I have been able to discover.  I do not think Volstro noted any collet designation of type or angles at each end or anything except the obvious bore dia. As noted 1/2 "  max and maybe 1/8 " min ?  Still searching&#8230;


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## MachineTom (Jul 25, 2015)

I am mobile right and cant check the unit. Gogle Double Taper Collet. Thrn check dimensions.


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