GailInNM said:
Tom,
You can turn an adapter to fit a center drill. Shown in the photo are two that I use. One with a 3/8 shank mounted in a NMTB 30 holder and one with a 3/16 shank to hold in a collet. Both are 1/8 diameter center drills. Start with oversize stock so you can turn the OD at the same time you drill and ream the hole for the center drill so the OD and ID are concentric. I just Loctite the center drill in the adapter using a high strength Loctite such as 640 or 680. When it comes time to replace the center drill, heat with torch until the Loctite releases and pull the center drill out with pliers. When cool, run a reamer through by hand to remove any residual Loctite before installing a new center drill.
I have run drill chucks with a straight arbor in end mill holders. Biggest disadvantage is the length of the assembly means any runout in the system really shows up and the length often means you have to lower the table to get clearance. NMTB 30 with 1/2 inch chucks are fairly easy to find when the tooling budget permits. As I do mostly small work, I made two NMTB 30 mounts for drill chucks. One for a 1/4 inch chuck and one for a 3/8 chuck. This was mostly just to shorten up the length of the tool so I did not have to crank the table.
I have had good luck with Shars.com end tool holders. Just search the site for NMTB 30. End mill holders up to 1/2 inch are $23.
The Bridgeport BOSS that you have takes the NMTB 30 toolholder. It was an option on that model. It will NOT take a BT30 toolholder. A BT30 will fit in the spindle, but the drawbar end is metric to take a tool retainer knob while your drawbar is 1/2-13 thread. The BT30 is used on machining centers with tool changers.
Often times you will find the NMTB 30 listed as a #30 or 30 INT. Be careful on Ebay as some sellers don't know the difference.
It would be helpful if you would put your location in your profile at least, and preferably in the avatar text line (you don't have to have an avatar) or signature line. Even putting USA in helps. A lot of people will not respond to "where to get" requests if they don't at least know what country you are in. I saw the trailer license plate in one of your "followed me home" photos. If you need help putting it in any of the moderators, including me, will be glad to help you.
Gail in NM
Thanks for the info. I spent several hours searching the net today and found this tool holder
http://www.tools-n-gizmos.com/store...271235.32324*EQ8FC7&p_id=27333&xm=on&ppinc=1a
which appears that it will do the job. Spent a lot of time going through his site, and it appears that he is really conversant with the various types of toolholders, and explains why you can use some #30 tool holders and not others.
If I'm understanding the picture right, it will accept a #1 morse taper. I've got several chucks of various sizes which came with the Sherline, and most or all of them have a removable arbor (if that's the right word), and both #0 and #1 arbors are supplied. But I understand that I'll have to chuck it in the lathe and take about 0.1" off the flange diameter.
But I also like the idea of turning a piece of material (aluminum?) and gluing in a center drill. Seems to me like the small diameter of the center drill would mean that very little torque is needed to drive the center drill, so a set screw wouldn't be required.
I also have a HF (pos) drill press with a nice big keyless chuck on a bigger morse taper. This drill press has a very limited vertical range, and I frequently find that it's just not big enough, even for smaller projects. If I had a nmtb 30 morse tool holder which would fit it, I might just move that chuck to the mill and move the drill press to a yard sale. Somebody ought to be stupid enough to give $5, or even $2 for it.
I've updated my profile a little bit. Have an avatar picture around somewhere, but don't know where to find it at the moment. For whatever reason, the info doesn't show up in my posts. Suppose Rick needs to approve it first.
Used to work on weekends in Arizona highlands. Would fly all afternoon, but it's be too late to land in Arizona, so spent the night on the couch at Southwest Air Rangers in Albuquerque. Would then leave Arizona late evening and spend a second night on the same couch. Those were good times.
