boreing the simple way

[nhbaler]

I need to bore a hole about 3/4 inch and put a bushing in itI dont have a lathe just a drill press,what kind of tooling should I get to do this with and yes I am a rookie just beginning to learn

 

[Terrywerm]

Check the actual OD of the bushing first. You might be able to get by with using a 3/4" drill bit. If that is the case, and depending on the size of your drill press, I would look for a set of Silver and Deming drill bits. They are usually not terribly expensive, and will probably give you the best bang for the buck if your drill press will handle them. I've got a five piece set which includes 9/16", 5/8", 3/4", 7/8", & 1", all with 1/2" shanks. I paid about $30 for the set about 30 years ago, so I expect you will pay more for them now, but I've used them an awful lot. Chances are the OD of the bushing will be right at .750" and the drill bit will tend to go oversize by a few thousandths so will not work.

I have cheated already in such a situation by drilling the hole, then peening the inside of the hole with a center punch. This raises the metal around each punch mark, and making a tighter fit for the bushing.

 

[mzayd3]

I have cheated already in such a situation by drilling the hole, then peening the inside of the hole with a center punch. This raises the metal around each punch mark, and making a tighter fit for the bushing.

Terry,
I am curious. How do you peen the inside of a bore?

 

[JimDawson]

Depending on the accuracy required, I would drill it about 0.015 undersize (47/64 drill bit), then ream to size. It will be dead on when finished. Center drill, then drill with a 1/4 for a pilot, then the 47/64, then ream. Slow down to about half drill speed when reaming if possible with your machine. Use cutting oil for all of the operations. Make sure the work piece is secured to the table for safety.

 

[nhbaler]

Thanks Terry for the info,but can I use one of those boring bars on my drill press? Like I said I am a rookie at this

 

[JimDawson]

It is possible to use a boring bar in a drill press if you have a way to adjust the tool bit depth accurately. The other requirements are that the work be clamped securely to the table, and the drill press is a reasonably stable machine.

Here is a reasonably good write up on boring bars. http://en.wikipedia.org/wiki/Boring_bar

A boring head and a set of bars would also work in a drill press. This one shows an R-8 shank, but you can get them with a 1/2 inch straight shank or a Morse Taper shank to fit your drill press spindle. These range in price from about $60 to several hundred depending on size and quality. Ebay might be a good source.

 

[Round in circles]

I need to bore a hole about 3/4 inch and put a bushing in itI dont have a lathe just a drill press,what kind of tooling should I get to do this with and yes I am a rookie just beginning to learn

How thick ( give dimensions ) & what style is the material that you are hoping to put the bush in ? IE hollow box, solid bar, flat bar thick sheet etc. etc. ?

 

[Terrywerm]

Terry,
I am curious. How do you peen the inside of a bore?

I must admit that I made a slight error in the use of the word 'peen' when I should have said 'stake'. Staking with a punch will raise up the material around the punch mark to tighten the fit.

 

[Terrywerm]

Thanks Terry for the info,but can I use one of those boring bars on my drill press? Like I said I am a rookie at this

Like Jim said, it is possible to use a boring head and boring bar in a drill press, but it may not work very well. Most drill presses are not strong enough for that kind of work and will flex too much, possibly ruining your workpiece. Using a drill bit and reamer would be a much better way to go on a DP, and would be cheaper than purchasing a boring head and boring bar as well.

 

[kwoodhands]

I need to bore a hole about 3/4 inch and put a bushing in itI dont have a lathe just a drill press,what kind of tooling should I get to do this with and yes I am a rookie just beginning to learn

Layout the centerline.Use a shop made pointer in the chuck.I make them from broken tool steel like taps or even a machine drill.Grind a long point on the tap so it is sharp. Chuck it up and center the work.Replace the point with a #5 center drill.
Then progressively larger drills.Unless your drill press is rigid and at least 1 hp a 3/4" hole will be difficult.You will need Silver & Deming drills ( turned down shanks) after 1/2". The larger drills are expensive,often flea markets can be a source of these drills.If the hole is a bit loose,Red Loktite will help. Iff it is a bit tight you may be able to freeze the bushing and heat the part with the hole with a heat gun.Then pressing the bushing in becomes easier.
If the hole is in steel use plumbers cutting oil for a lube.
mike