Is there a longer R8 spindle for Bridgeport Boss CNC conversion?

I have two mills using r8 taper spindles. I have a Bridgeport Boss CNC type setup on one mill with a QC40 with a solid spindle. I want to change the Bridgeport to use the same tooling as the other two. Because of the spacer where the servo connects to the downfeed, the old spindle was longer than a standard series 1 spindle. When I put the standard spindle in, I can only extend the quill a few inches before it disengages from the spline in the head. Is there a longer R8 spindle for these type setup or is there a QC with the same taper as an R8 and a hold for a drawbar? I understand that QC is better than R8 for speed but we have a very limited budget and being able to swap jobs and tooling makes a lot of sense.

Swapping a 40 taper for an R8 is insane.

Are you sure it's a 40 taper? Many are NMTB 30 commonly known as National 30 (the keys on the spindle fit into the holders),
others are Universal Quick Switch (with keys that stick out of the holder)

Sorry, it may be NMTB 30. I didn't go back and look, so am not sure. It has a solid spindle and uses a spanner wrench on the quill to accept the tool holder. The spindle isn't marked and I don't have the holder here. I just know that buying tool holders for it seems more expensive than just using the R8 tooling I already have for two other machines. So, the question is, is there a spindle that is the right length that will accept r8 holders? Or is there something that has the same taper and is hollow so that it could be used that way or am I stuck buying tooling?


It looks like this one:

I believe Erickson QC-30 (NMTB 30) was an option on the Series I 2J2 manual mill, so they should be out there. You might want to check with H&W: H&W Machine Repair & Rebuilding - Parts and Service for the Metalworking Industry or High Quality Tools: http://highqualitytoolsinc.com/ and see if they have a new spindle in stock.

Dennis

Better late than never ?

Nephilim said:

I have two mills using r8 taper spindles. I have a Bridgeport Boss CNC type setup on one mill with a QC40 with a solid spindle. I want to change the Bridgeport to use the same tooling as the other two. Because of the spacer where the servo connects to the downfeed, the old spindle was longer than a standard series 1 spindle. When I put the standard spindle in, I can only extend the quill a few inches before it disengages from the spline in the head. Is there a longer R8 spindle for these type setup or is there a QC with the same taper as an R8 and a hold for a drawbar? I understand that QC is better than R8 for speed but we have a very limited budget and being able to swap jobs and tooling makes a lot of sense.

Click to expand...

I stumbled onto this older thread and thought I would add a solution for future readers. I have a Bridgeport 2 CNC that has a QC40 spindle (Erickson Quick Change, #40 taper). I also have a lot of R8 collets for my Rong Fu mini mill. To utilize my existing R8 collets, I purchased a new QC40 to R8 adapter made by Bison for $125.00 through Amazon. I realize this would not be ideal for a production shop unless the setup was used for non-precision or lighter cutting. My shop is a prototype / R&D situation where flexibility is more important than milling speed at this point.

Since the R8 drawbar is replaced with a machine screw that is accessed through the narrow end of the 40 taper, I don't believe that a QC30 version of this exists. I can picture a design but it's not practical and would extend a full R8 length outside of the nut. Besides, 30 tapers look very light duty in comparison to the 40 taper. If one exists I would only use it for light cuts in a long reach situation.

If you have your solid spindle gun drilled, you can now use a drawbar.
Now you can use basically any 30 taper tool (NMTB, CAT, BT etc) with the proper drawbar.
You could even put the QC40 to R8 adapter made by Bison in the QC and have the R8 collet held in with a drawbar.

Bill

Im sorry, I know this is an old post but come on guys. The guy asked a simple question. "IS THERE A LONGER SPINDLE FOR THE BRIDGEPORT BOSS CNC" You did nothing but get off topic and never answered the question. Why can't you just answer the actual question instead of instantly getting into which taper is better. Give me a break. The taper discussion is on every single thread, can you ever get over the fact that some people don't care. Just answer the stupid question. Yes someone peed in my wheaties today.