drilling a hole 12inches deep???

   / drilling a hole 12inches deep???
  • Thread Starter
#11  
Well, failure. I managed to drill all the way thru it with a pilot bit. drilled it about 4inches deep from each end with a 1 in drill bit, largest I own. Then decided to try using different size hole saws. This worked ok, but I didnt have the inbetween sizes I needed to go from 1in to 2 in. I finally decided to put this projectoff until I can just buy DOM tube of the right size. Cut to length weld in and done. I think I could have finished the bushing with what I had to work with, but after a day on this one, and still not done, and needing two such bushings, and knowing I needed at least one more hole saw to make it work, and having to make a extension. I got other things to do while I wait on the DOM.
 
   / drilling a hole 12inches deep??? #12  
If you have a welder and lathe you should be able to either make an extended drill bit or an extended drill bit holder for any drill bit. As well as extended boring bars.
 
   / drilling a hole 12inches deep??? #13  
What is this being used for? Maybe if you could describe the use or better yet take a picture, there might be an easier solution.
 
   / drilling a hole 12inches deep??? #14  
Now that you have a hole through it - the 1/4" - can use a boring bar and do light face cuts to rough it out. Facing cuts to the absolute center can get real tricky. Then go in and do a deep cleanup pass or two to smooth out the ID. Just have to be real careful and be int he right place when you go in and how far you travel in X & Y. Everything is blind so you have to go by the numbers unless you have a programmable lathe.

Be sure to turn the OD first so that when you turn it around you stay on center. I would turn the OD but leave some cleanup to be able to take out the exterior jaw marks due to the ID boring work.
 
   / drilling a hole 12inches deep???
  • Thread Starter
#15  
What I have is a piece of 2 1/2in solid round bar and I want a 2in hole all the way thru it. My lathe is a 1948 monarch that when I bought it didnt come with a lot of tooling. I bought the lathe several years ago just to make some pins for trackhoes, backhoes, and the like, and didnt need a lot of tooling to get that done. I am not a machinist and really dont have a lot of experience using machining tools. With that said. I learned a lot from this experience, mainly why real machinist charge what they do. Setup time and actual time cutting 12 in deep holes isnt as easy or as fast as one would think. My lathe has the older rocker post tool holder. When ever I tried using the boring bar extended out to reach 12 inches deep, it wouldnt stay put in the rocker post. No level of accuracy at all. I also dont have any kind of coolant setup, which means I would cut for a bit and then have to wait for things to cool down before continuing. For the amount of time already spent, (I really didnt think it would take as long as it did), and knowing it would take equally as much time to do a second bushing, I just threw in the towel. I am sure with proper tooling I can bore this hole, and a lot faster than the time already spent, but I just aint willing to buy a $150 drill bit for a one time project. Especially when I can by enough DOM tubing to do both bushings for about $60. Thats the easier solution I think. Although, I will most likely purchase a better tool post sometime in the future, been planning on getting the tool post for some time now. It seems when I need it, I dont have it, and when i dont need it, I dont think about it.

I have a buddy that is the head of the machine shop for Moog, He was going to take it to their shop, which has millions of dollars worth of equipment, and even they didnt have the proper tooling for a 2 inch hole 12 inches deep, not what they do since most of the stuff they do is very small, so I dont feel real bad about not getting this done. What I have found out is having a lathe without tooling is like having a tractor without any attachments, Looks good setting there, but not worth much without a plow to hook behind it.
 
   / drilling a hole 12inches deep??? #16  
What I have found out is having a lathe without tooling is like having a tractor without any attachments, Looks good setting there, but not worth much without a plow to hook behind it.

Well said. Tractors, lathes, mills, etc are just basic machines. Without the accessories they are not real useful. With them miracles can happen.
 
   / drilling a hole 12inches deep??? #17  
You need a long boring bar... And take it slow so it doesn't deflect. Shouldn't be to difficult. Good luck.
 
   / drilling a hole 12inches deep??? #18  
If you're interested, I have a spare 1-7/8" drill you can have. The flutes are right at 6" long, so you could get the majority of
your hole drilled, then use your boring bar.

Drill.jpg
Drill Size.jpg

Not sure of the taper, but you could possibly turn it to fit your tailstock...

Feel free to PM your address, and the USPS will be thrilled to deliver!

Tim
 
   / drilling a hole 12inches deep???
  • Thread Starter
#20  
 
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