Millrite MVN - Question - Collet holder

[Bill Rosselot]

Ok I've got a Millrite MVN with a spindle that is ground to NS30 taper with I found out means National Standard. It came with a Universal NS30 Collet holder with ZZ collets which are very hard to come by and expensive. I have a NMBT30 tool holder I got from WONG FU and it fits well I measured it and it is not any different other than the drawbar will need a spacer because it is to long for a tool holder by about an 1/2" not a big deal.
The questions I have is:

1. I found a NMTB30 Collet holder with ER32 Collet set I've never used collets but are ER32 good for milling?

2. What is the difference between an NT30 Tool holder and NMBT30 tool holder. I guess I'm missing something?

 

[Bob Korves]

ER32 collets are good. I think I would prefer ER40 on the Millrite. They will take up more headroom than 30 taper collets holding tools directly. While I have a set of R8 collets by sixteenths for my Millrite MVN, I actually prefer tooling with short, straight shanks. Then you can put them in any kind of collets, and they take up less headroom to change the tooling while working, without moving the part away from under the spindle. With a 30 taper on your MVN, you will probably not want to go spend a bunch of money on new 30 taper tooling. If you get a few 30 taper collets, like 1/2, 3/4, and 7/8 or 1", and have your various tools with those shanks, then you can get by with less collet changes, and less collet purchases. And, if you ever decide on a different machine, your tooling will still be valuable to you. You can then pick up more 30 taper tooling if and when it comes along at good prices.

 

[bss1]

I know nothing about a 30 taper but I agree with BK on the straight shanks for tooling. My Millrite has the BS9 taper. Not near the selection for tooling as R8. Therefore I have assembled a small collection of tooling on 1/2" or 3/4" shanks such as drill chucks, boring heads, saw arbors, etc.

 

[richl]

My machine is a bit of an orphan also, a 1956 south bend knee mill. It has a 30 taper also, but no drawbar, tooling is held in with screws.
I purchased a bt30 to er40 collet chuck. Ebay, around 60 dollars. With this and a couple other chucks I cover the main areas of interest for milling operations.
As far as 30 taper goes, what I am told, there is no difference in the taper, only the drawbar end. If you find out different, I would be curious to hear.

Hth
Rich

 

[Bob Korves]

As far as 30 taper goes, what I am told, there is no difference in the taper, only the drawbar end. If you find out different, I would be curious to hear.

Not sure, but there may be some differences in the drive dogs as well. The larger tapers, 40 and 50, have some differences in those areas from type to type. The main taper size and length is definitely the same for all 30, 40, and 50 tapers, the differences are just proprietary adaptations...

 

[Bill Rosselot]

Thanks guys
I found out that NMBT30, NT30, NST30 and ISO30 are all the same and can be used in my machine. Now I have a 1/2-13 Drawbar so it makes it alot easier. I'm going to go with a NMBT30 Collet chuck and ER32 collets from 1/8" to 3/4" I have a Universal 30 Collet holder that came with the machine but uses ZZ Collets, same as most Tree Machines, there is quite a few out there but mainly in odd sizes. I will keep my eyes open.

I can go with 30Taper End mill holders but will need to modify my drawbar it is about 3/4" to long because tool holders do not have a trough hole in them like the collet chucks have. I talked to a guy about this and if I stay with 30taper tooling when and if I ever go to the "Dark Side" (CNC) I will have tooling