Van norman no. 12 in florida

[captcory]

I just picked up my very own VN 12. It has the horizontal arm support. no tooling except for a horizontal mill holder and cutter. I think the spindle has been changed. I don't know what taper it is. I my delight I ordered a VN c collet 5v, but I don't think it will work. here are a couple pics. can you guys tell me what I have?

 

[markba633csi]

Good that you got the arbor support, those are hard to find.
The 12 supposedly uses a 5V collet- did you say you bought one and it doesn't fit? - I think it uses a hollow drawbar
mark
ps how are the spindle bearings?

 

[captcory]

The draw bar that I have is just a home made all thread with a nut welded on going into what looks like a r8 collet with female threads. There is no keyway in the spindle at all. Haven't taken the head apart to examine the bearings. They seem fine not noisy or loose. Ill put a dial indicator on the spindle and see how much run out I have. I ordered some r8 collets to see if they will work. Someone modified this spindle and I'll have to determine how.

 

[markba633csi]

Unless someone told you the spindle taper has been modified I would assume it's still stock which is 5V and not common. They do show up on ebay though
Van Norman called it "C" taper, same as Hardinge 5V. It's similar to R-8 but not quite the same.

 

[Cal Haines]

I just picked up my very own VN 12. It has the horizontal arm support. no tooling except for a horizontal mill holder and cutter. I think the spindle has been changed. I don't know what taper it is. I my delight I ordered a VN c collet 5v, but I don't think it will work. here are a couple pics. can you guys tell me what I have?

You're right. The spindle has clearly modified or perhaps replaced with a shop-made spindle. The lack of slots for the drive dogs is one thing that leads me to believe that it was replace, rather than modified. Look around the area of the taper; if there's no small hole, where the "tit" for the C spindle drive key, then it was most likely replaced.

From the photos, it looks like R8 is a good guess. We need some dimensions to know for sure. Check the dimensions and drawbar thread against the dimensions for an R8 tool and let us know: http://www.tools-n-gizmos.com/specs/Tapers.html#R8

 

[captcory]

Thanx cal , hope you would respond! The taper is clean... no holes or slots nothing. I didn't measure the spindle taper but I did measure the collet that came with the machine that fits snug and it is most likely a r8 according to the specs as measured by my calipers for a quick check. I forgot to check the draw bar thread size and pitch. will do as soon as I am able. Don't r8's have a key way? my spindle in smooth. Also there are no drive dogs is this going to be a problem for tooling that has them?

 

[Silverbullet]

Looks 5v to me. They look simular to r8 but the taper is different and larger , the spindle hole in one picture look like there's a key way internally . Not sure but looks like there is. As said the arbors you have are great to have lucky to get too. If it becomes to much for you I'd be glad to use it a few years on a $1. A. Month lease.. sounds good don't it . YUPP it's a on my most wanted list.

 

[Cal Haines]

Yes. R8 collets have a keyway and the spindles have an alignment screw, basically just a setscrew with a square tip. The screw is just there to keep the collet/tool from rotating while the drawbar is tightened; the taper is what does all the work to keep the collet/tool from rotating inside the spindle during use. Your spindle should work fine without it, but you need to be careful to keep the spindle and tool very clean and take pains to keep the tool from rotating and galling the spindle as it's tightened.

Your spindle looks very rough inside. I don't know how well the taper will hold, particularly with that big slab mill. When you get a new R8 tool (preferably an endmill holder, not a collet), used high spot bluing to locate and remove the high spots in the spindle until you get good contact between the tools and the taper. A round-tipped scraper would be the best thing to start with. I have some round-tipped scrapers that I got from either Enco or MSC, but I'll be darned if I can find any for sale now. Push comes to shove, you can grind your own scraper from old files. Ideally, you would like to have the spindle professionally ground, but there's no harm in trying to improve things by hand.

 

[captcory]

Yes the spindle is very rough. Where would I send it to get it reground? In the mean time I will clean up as good as I can. here is a pic of a genuine van norman 5v collet next to what came with my mill. So basically a 5v next to a r8. You can see the difference in the taper and in the different style of draw bars. I'm actually very glad it has been converted...so much cheaper/easier to find tooling. As long as I can get it cleaned up and working properly. Biding on a set of end mill holders as well. Good thing I got the machine cheap! now I can spend money on tooling. Isn't that always the case!

 

[Cal Haines]

I don't know who to recommend for a regrind. Several companies pop up if you search online for "R8 spindle grinding". If you go that route, the company can easily add the missing key.

I don't consider an R8 conversion to be an upgrade. The No. 12's real forte is horizontal milling and R8 horizontal milling arbors are inferior to "C" spindle arbors, due to the lack of drive lugs. You won't be able to take as heavy a cut with an R8 arbor as you can with a "C" arbor.