Thread: Long stroke drill press

Hi,

I have a project in mind where I need to drill a lot of holes through 50mm SHS. I'm planning to bolt two lengths together for the drilling operation as I need the holes to align.

I've been looking at the belt driven units. Apart from Carbatec and Hafco are there any others that have a stroke of greater than 100mm?

thanks
Andrew

I am not aware of the specs of any drills right now, but can you not just clamp your workpieces together, drill through the top and at least part way through the bottom piece, then unclamp to finish the holes? What's your location tolerance for? Bolts?

Greg

One of your issues here will be finding drill bits long enough. Bit length depends on the hole diameter but to get drills 100mm long you would have to go to an industrial supplier and pay for the privilege of that extra length.
If an employer asked me to do something similar to what you have described, I would probably look at using a drilling jig first so that I had repeatable hole positions, even if it meant flipping pieces over rather than drilling through 2 sides of RHS - therefore I wouldn't have to drill through two pieces to have them located properly.

Michael

I want to make one of these.



Basically a 1/2" shaft needs to pass through two uprights spaced 24" apart. Through the bench area the holes are spaced at 1" intervals.

If the holes aren't perpendicular or aligned in the Z or X axis then the pin isn't going to pass through all four holes. It needs to be accurate or use a sufficient tolerance.

I don't have the experience to be able to specify the tolerance. If you can that would be a help. I'm guessing a 5/8" hole. That said I intend to use metric because that's how steel is sold.

The three options I could think of was
1) bolt them together get a press that's true, use a fence, mark the holes up, center punch, then clamp and drill. Requires 100mm + stroke
2) bolt them together and drill through the first three surfaces and then unbolt the uprights and finish the last hole.
3) make a jig with a pin so that I just progress the tube one hole at a time.

My concern with 3 is that I might get a cumulative error due to any tolerance used that will put me out by the time I get to the end of the tube.

My intention during welding was to use the pins as an alignment tool.

I don't have a drill press.

Andrew

Originally Posted by chalmers888

I want to make one of these.



Basically a 1/2" shaft needs to pass through two uprights spaced 24" apart. Through the bench area the holes are spaced at 1" intervals.

If the holes aren't perpendicular or aligned in the Z or X axis then the pin isn't going to pass through all four holes. It needs to be accurate or use a sufficient tolerance.

I don't have the experience to be able to specify the tolerance. If you can that would be a help. I'm guessing a 5/8" hole. That said I intend to use metric because that's how steel is sold.

The three options I could think of was
1) bolt them together get a press that's true, use a fence, mark the holes up, center punch, then clamp and drill. Requires 100mm + stroke
2) bolt them together and drill through the first three surfaces and then unbolt the uprights and finish the last hole.
3) make a jig with a pin so that I just progress the tube one hole at a time.

My concern with 3 is that I might get a cumulative error due to any tolerance used that will put me out by the time I get to the end of the tube.

My intention during welding was to use the pins as an alignment tool.

I don't have a drill press.

Andrew

5/8 would be overkill I would think. The holes would definetely line up unless the welding was seriously second rate. It is also at lot more difficult to drill 5/8 than 1/2. I would suggest a 13mm drill bit for the final hole. I would predrill with a 3 or 4mm drill first. This will make it easier. The main force from drilling a hole is from the web of the drill. Predrill with a drill bit just slightly bigger than the thickness of the web and this will reduce the effort required considerably.

I would clamp 2 pieces together accurately aligned at the base, use two jigs to centre punch the position exactly centre for the 2 diff spacings and at the required seperations ( 1 jig 2 holes). Drill using a standard drill press with the table accurately set square to the quill, right thru the first RHS and the first side of the second one. Then finish the hole thru the second RHS after. I have a support for my drill press which is clamped via a bracket under the table. CS bolts thru the table to do the clamping. A length of 30mm RHS is clamped against the bottom edge to keep it level with the table. I think you will need something like this. If you only use the jig for the marking it will not matter if there is a slight variation of seperation.

When welding you will need to use more than pins to provide alignment. Clamp top and bottom of the uprights and use pins. You should also ensure that the uprights are kept parallel by clamping across the face of both at top and bottom, tack at every possible position and the weld. There may be better methods to weld. Ie order of welds to follow to limit distortion.

A drill press would be almost a necessity for this job. Since I bought one I hate drilling steel with anything else. More accurate, easier by far and less wear and damage to drill bits, not to mention damage to yourself.

Dean

Have you considered pre punched? Just a suggestion, as I am not sure what is available in this stuff. They do say hole centres are unrestricted on this page.

PUNCHED RAIL

Nev

Nev, what manner of black magic is that? I've never seen the stuff before. Worth a call.

I'd considered laser etc but the setup just kills it. I'd not thought of punching. I wonder how hard it is to program.


Dean, thanks.

Some pre punched stuff is used for fencing. Spacing is a bit wide for what you want though. I'm not all that familar with the stuff, so a little searching and a phone call or two should help find what's available and whether it is suitable for what you want.

Nev

Jet have the longest stroke that I have found in 240 volt drill presses, over 100mm on my 17 inch, I think I can fudge another inch if I take off the stop nuts on the depth stop. The newer continuously variable speed presses from Jet & Powermatic may go deeper.

Other than that you should go around the second hand machinery dealers, a friend has a couple of old industrial 415 volt drill presses with 150mm+ of stroke, but you would need either 415v 3 phase power or a new motor (& the hassle of fitting it). You might even get lucky & find a 1940-50's press with a long stroke in 240v, but 240v machines are popular with hobby workers, so command a higher price & sell quickly.

I hadn't considered the JET. More $ than the Arboga EM825 mill on ebay recently.

I do have 3 phase.

I'm still waiting for the steel supplier to go back to work to find out about punching.

I know hare & forbes have some used machinery. Do you know of any others in Sydney?

Andrew

Plenty of second hand places, look here Used & New Heavy Industrial Machines, Machinery & Equipment for sale at Australia's No.1 Online Machinery Market.
Sorry, been on a French forum and my English is struggling.....to many bad translations! (its all BT's fault)