Problems and solutions

[might_make_it]

I have made a slitting saw arbor and neglected to drill and tap a 3/8-16 hole in the back of the morse taper for the drawbar. After some careful consideration this was my solution. I mounted the drawbar in my boring bar holder and threaded the hole for the cap retainer onto it tight against the holder. (Lucky me I went 3/8-16 for the cap screw) I set the holder’s height and cross slide position by placing the taper in the spindle. It was a bit sketchy but I went slow and it worked out perfectly. I now have a very nice arbor with about +/- .00015 runout that will not accidentally come out of the spindle. A very challenging little project for a first real project but well worth the effort and a lot was learned.

 

[brino]

Good save for making a draw bar threaded hole where you need one when it should have been an earlier operation.
You certainly cannot grip that Morse taper in your chuck!

I believe that it's the Morse taper responsible for the actual centering and tight run-out, the draw bar just ensures it doesn't eject prematurely/accidentally.

Hey that's your first post......

Welcome to the group!



Brian

 

[might_make_it]

Good save for making a draw bar threaded hole where you need one when it should have been an earlier operation.
You certainly cannot grip that Morse taper in your chuck!

I believe that it's the Morse taper responsible for the actual centering and tight run-out, the draw bar just ensures it doesn't eject prematurely/accidentally.

Hey that's your first post......

Welcome to the group!



Brian

Thank You! I’ve been reading for a while and finally did something I felt was worthy of sharing. Up til now all I had made was a handful of short shafts with no critical tolerances. This however was a whole different different kind of critter especially with getting the Morse taper fit just so and the straight portion had to actually be straight. I will have to take a picture of the finished piece next time I’m in the shop.

 

[Just for fun]

Welcome to the group, looks like you did well! Looking forward to the end product.

 

[woodchucker]

Just a suggestion for next time. Keep the stick out as short as possible. That is hanging out quite a bit, and will flex a bunch. You may not see the flex, but it will be there, and if it starts chattering, well, that would be a place to look.

As for that project, nice job... just learn to keep things as short as you can get away with.


edit: maybe I got the part wrong... sorry.

 

[might_make_it]

Just a suggestion for next time. Keep the stick out as short as possible. That is hanging out quite a bit, and will flex a bunch. You may not see the flex, but it will be there, and if it starts chattering, well, that would be a place to look.

As for that project, nice job... just learn to keep things as short as you can get away with.


edit: maybe I got the part wrong... sorry.

The whole thing is kinda long but it was intentional. In the picture the entire part is held by the drawbar threaded into the cap screw hole and then held in a boring bar holder. The whole part is hanging off of the tool post because of needing to drill on the taper side and my chuck and spindle couldn’t accommodate the 1” shaft and this setup was more secure than holding it in the chuck with the stick out. But the straight part for mounting the slitting saw(s) to is also long so I can stack slitting saws to cut multiple slots or cooling fins in one operation. In the picture the spindle has a mt3 to jt33 arbor with a jt33 to er20 collet holder that has a center drill held in it and I used that as my tap drill because I didn’t have any regular drill that was short enough. It was a questionable setup without a doubt but I took it slow and it did work. If I had to do it again I would probably figure out something a little less sketchy.