View Full Version : Anyone want to buy a dedicated 41mm horizontal boring machine?

Black Forest
05-13-2010, 08:07 AM
I needed to bore a 41 mm hole in a half inch plate. I thought I would use my horizontal mill to bore the hole. My 41mm drill bit has a mt4 taper. My mill has a mk5 taper spindle. No problem I just grabbed a MK5 to MK4 reducer. The reducer does not thread into the drawbar. It just sits in the spindle taper. So I drill my hole, no problemo! But now I can not get the drill bit out of the reducer or the reducer out of the spindle.

My next step is to heat the protruding part of the spindle a little and see if I can get it free.

I have done this in the past with no problems. Drilled lots of holes in the last few weeks this way.

If I can't get it out then anyone need a dedicated 41mm boring machine!!!!!

05-13-2010, 08:37 AM
replace draw bar with bar of steel (or just use draw bar, they are technicaly consumable..)
put soft object to catch drill bit under drill bit (idealy not a hand, but hey, its your hand)
wack top of bar with lead or deadblow hammer.

Note if you do replace the drawbar, make sure its the exact same diamiter as the hole the drawbar goes into..

05-13-2010, 09:06 AM
Some horizontal mill spindles are threaded on the back end. If yours is threaded, you could make a collar to thread onto it with a piece of all-thread going through the middle and push it out by screwing the all-thread against the back of the reducer.

Black Forest
05-13-2010, 10:15 AM
The dedicated 41mm boring machine is now back to being a horizontal mill!

I have only had this mill for three weeks. I did not know the hand wheel on the back of the spindle unthreaded and that is how the drawbar is removed.

I put a wrench on the nut of the handwheel and another wrench on the reducer in the spindle. My plan was to try to twist the reducer to free it. The reducer did not turn in the spindle but the handwheel unthreaded and and I could then take the drawbar out. In the big box of "stuff" there was another drawbar with a smaller threaded end. I thought it maybe belonged to another machine. But it threaded into the back of the reducer and pushed it out with no problem. Good lesson learned.

But this machine is really good for drilling big holes. I mainly bought it to use as a saw for pipe. And for notching pipe to build fence on my horse pastures.

05-13-2010, 02:47 PM
You're welcome!

Black Forest
05-13-2010, 03:47 PM
Thank you for the suggestions.