drilling a hole 12inches deep???

[muddstopper]

been trying to figure out how to drill a 2in hole, 12inches deep in some round stock. I have a lathe, but no drill bit that size. Dont have a drill bit that will reach that far except for some aircraft bits, 3/8 I think being the larges size. Thinking about making a drill bit extender and drilling starter hole and then going with boring bar, but my boring bar wont reach 12inches in a hole. I can probably flip the piece and drill/bore from each end, but even 6in deep is a lot of peck and drill and the biggest hole i can drill is 1in. Without resorting to buying an expensive gun drill that would only be used once, anybody have any suggestions. any way I do this, it seems its going to be a long process

 

[CNC Dan]

Tubing?

 

[ishiboo]

2" annular cutter in the lathe, flood cooling. Not sure what you can use to extend it once you're out of tailstock travel, but the bit itself will be kept aligned by the hole so it will not need to be real rigid, just push the bit and keep it from rotating.

 

[muddstopper]

I thought about the tubing, but steel supplier didnt have any correct size in stock. As for the annular cutter, I've never seen one that could drill 12in deep. And I dont have one anyways. I did consider drilling the hole to 1 in and then using hole saws to cut out to size, but it would mean constant swapping of hole saws of different sizes since the hole saws I have will only cut about 1 1/2 deep. If I can get the hole big enough for the boring bar to fit in then I can probably just swap ends to get the full 12in's

 

[ishiboo]

You want to drill a 2" hole 12" deep in steel with only what you have on hand? Good luck

As I said, with an annular cutter you would kneed to extend it once you're out of tailstock travel. It's as simple as a 3/4" ID DOM tube with two set screws drilled 90 degrees apart.

Hole saws at 2" in solid steel are a pain in the ***.

 

[bigdeano]

You could probably make a 2" drill bit by brazing a high speed tool bit crossways on the end if a shaft that will fit in your boring bar holder. Sharpen it so it works as a spade bit. You'll need your 3/8 pilot hole first, and a 2" starter hole to help center it. I've drilled 5" holes in aluminum with flat bottom spade drills, but they weren't homemade. Interesting machining challenge.

 

[BHD]

go to Enco, buy a Chinese bit, Enco - Guaranteed Lowest Prices on Machinery, Tools and Shop Supplies or MSC https://www.mscdirect.com/?cid=ppc-...41&006=27864417304&007=Search&008=&025=c&026= .

and then if you have a lathe make an extension holder on the shank so one can go up to 12 "

you will have to drill 1/2 may be 3/" of an inch and back it out,

pre drill with a smaller bit for a pilot(3/8 to1/2"). a 2" bit will have a hard time if there is not a pilot hole for the center of the bit,

and if this need some precision you may be better off getting some DOM tubing /shaft any machine shop worth it salt should be able to get for you. (DOM= Drawn Over Mandrel)

and or if the tube only needs some precision on the ends put in some bushings on a pipe, you say you have a lath.

 

[muddstopper]

I was able to predrill the full 12 inches with a 1/4in aircraft bit. Took a while, but it just barely reached thru. I have drilled one end out with a 1in drill bit filpped it and am now drilling the opposite end. The 1in drill isnt going to reach in the middle. I most likely will make and extention to accett the 1in drill bit that will get me a 1in hole all the way thru. My boreing bar is 3/4dia, I havent measured the lenght bt it should b long enough to reach if I flip the piece. I did have a bit of run out with the 1/4 drill bit, not a lot, but enough to be noticeable. I think once the hole is bored using the boring bar, it should true up. 'This hasnt got to be real precise, but I cant wallow around either.

I know i can buy the right size drill and dom tube, but I have to order it and I am wanting this bushing now.

 

[BHD]

you may be able to take a bar and drill a hole and put a bit in it and use a set screw, using the bar as a pilot guide and run it through may have to cut off the back of the bit,

much like a boaring bar but the front using the drilled hole as a pilot guide

basically and adjustable counter bore tool

https://www.mscdirect.com/browse/tn...Kits?searchterm=counter+bore&navid=4287920446

 

[downsizingnow48]

Buy the high quality thick wall tubing from McMaster Carr, Metals Depot, or other supplier. It will be cheaper than any bit. Other than that, why not use the lathe and a boring bar.

 

[muddstopper]

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.

 

[jwmorris]

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.

 

[Mysfyt]

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.

 

[Creamer]

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.

 

[muddstopper]

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.

 

[Creamer]

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.

 

[PapaPerk]

You need a long boring bar... And take it slow so it doesn't deflect. Shouldn't be to difficult. Good luck.

 

[parvodog]

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.




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

 

[Brad_Blazer]

Here's another vendor. They had the best shipped price I could find for a couple of pieces of DOM I recently ordered.
The Best Place To Buy Metals & Industrial Supplies Online | Buy Metals Online | Buy Industrial Supplies Online | Cut to Size | No Minimum Order | CNC Laser Cutting | CNC Machining

 

[muddstopper]

Here's another vendor. They had the best shipped price I could find for a couple of pieces of DOM I recently ordered.
The Best Place To Buy Metals & Industrial Supplies Online | Buy Metals Online | Buy Industrial Supplies Online | Cut to Size | No Minimum Order | CNC Laser Cutting | CNC Machining

2 ft of 2.5in od x 2in id =$31.40 +shipping, I wasted more time than that trying to cut it. Should of just ordered it to start with:banghead: