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View Full Version : Annular cutters on a drill press???



torker
10-05-2007, 02:40 AM
Hey guys...I need a short term solution for drilling bigger holes at a faster rate.
I've used plenty of mag drills with annular cutters but I'm wondering how one would go about using them on a drill press? My press has a MT2 spindle. Is there some kind of adapter that would use the knockout pin/center finder that the mag drills use?
I need a bigger machine but til I find one this little 16" job will have to work.
Right now I'm at about 6 minutes for a 7/8" hole(time includes drilling a 1/4" pilot hole) in 3/8" plate. Last job there where 72 of these. 6 minutes is far too long when my competitors are using punches. I know I can't beat a punch press but would like to speed this up as much as I can.
The next job could require 1" or bigger holes so I'd like to get this figured out.
I'm betting you all have some good ideas for me!
Thanks!
Russ

Willy
10-05-2007, 03:03 AM
Russ I can't help you out with the annular cutter adapter but I think we both will agree on the flexibility inherent in most 16 in. drill presses. On mine whenever I need to drill holes larger than 1/2 in., either hole saw or drill bit, I usually put a hydraulic jack under the table to add rigidity. It sure takes the hully gully out of the equation and allows me to drill faster. Got to be a lot easier on everything else also. Can you use the mill/drill for the operation? It would sure make for a more stable platform.

tattoomike68
10-05-2007, 03:22 AM
Russ im sure you know this but an ironworker that will punch holes will save you tons of time. Annular cutters are just fancy hole saws that are not cheap and are slow.

Iv seen 100 ton buffalo ironworkers sell at auctions for <$1,000 and it will punch a 1" hole in 1" plate. I guy like you pick one up and it will make you money. You will leave the drill press for the little and deep hole stuff. The punch makes the money and I bet you are not in it for job satisfaction.

BadDog
10-05-2007, 03:34 AM
Hey Russ, glad to see you back among us.

Can't help on annular cutters much. Pretty pricey, and generally in the realm of the mill. Obviously, other options that are not fast, but much cheaper, would be trepanned and hole saws. And I know I've gone through similar size plate faster than that with a hole saw on my old HF 16 drill press. Just use lots of oil, and preferably a chip clearing hole drilled inside tangent to the cut. It's that or flood/blow clear. Chips are what slow/kill a hole saw.

If the finish is not critical, I've used a plasma cutter with a guide. I had a project that needed something like 30+ holes in 1/4" HR plate. And just to make it interesting, it was way to awkward to get it onto a drill press or mill. I made some hole guides for the plasma cutter some time back. The small guide will cut a 1" hole by itself. Just a piece of light tubing with some tabs welded on. Tabs get clamped to tacked to the part, and the plasma cutter collar slides along the ID. Then it's got inserts for various other sizes like 3/4 and 1/2". Nobody would ever mistake them for drilled holes, but they are surprisingly smooth and work fine for general assembly holes (these were take-down long range riffle target stands for the local range).

And not to rub salt in the wound, but look for a drill press like I just brought home. It would be right down your alley. MT3, geared head down to 80 rpm, 1.5hp motor, weights 700 lb, BIG floating table rated for 600lb static load, and can push a 2" taper drill through steel I'm told. Something like that or one of those gear head Arboga or similar would be just the ticket for a shop like yours. Pretty much over kill for me, but hey, overkill is good; right?

Timleech
10-05-2007, 04:09 AM
Hey guys...I need a short term solution for drilling bigger holes at a faster rate.
I've used plenty of mag drills with annular cutters but I'm wondering how one would go about using them on a drill press? My press has a MT2 spindle. Is there some kind of adapter that would use the knockout pin/center finder that the mag drills use?

Russ

Available in the UK:-


http://cgi.ebay.co.uk/MT2-ROTABROACH-ARBOUR-Myford-Boxford-Harrison-lathe_W0QQitemZ290165295831

Tim

oldtiffie
10-05-2007, 06:42 AM
Hey Russ, glad to see you back among us.

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If the finish is not critical, I've used a plasma cutter with a guide. I had a project that needed something like 30+ holes in 1/4" HR plate. And just to make it interesting, it was way to awkward to get it onto a drill press or mill. I made some hole guides for the plasma cutter some time back. The small guide will cut a 1" hole by itself. Just a piece of light tubing with some tabs welded on. Tabs get clamped to tacked to the part, and the plasma cutter collar slides along the ID. Then it's got inserts for various other sizes like 3/4 and 1/2". Nobody would ever mistake them for drilled holes, but they are surprisingly smooth and work fine for general assembly holes (these were take-down long range riffle target stands for the local range).



Yep BD - I'd support that.

Providing you've got the power supply and air supply, plasma is the way to go. Its portable (take it to the job) and light ("torch"/"cutting head") and relatively easy to use. Accuracy is quite surprising as well (with practice) and is not expensive. Preparation can be virtually nil providing the "earth/return" clamp can get a good connection. Machines are not too costly and are quite versatile. They will cut anything/metal that is "conductive" - hi/lo carbon/tool steel, aluminium, brass. bronze, copper, stainless - you name it. I'd suggest not "blowing" the job through for a start - a drilled 1/4">3/8" (preferred) "pilot/starter" hole will be fine.

Finish and size are surprisingly good - within limits. I've yet to get a consistently satisfactory line by "hand" - I always use guides.

IIRC John Stevenson gets his dividing plates that his wife sells on the net laser-cut and that's how they go out. As is well known - and expected - John's standards are very high and if laser cut is good enough for him its just about good enough for anyone - and its obviously cost-effective to "farm it out" instead of doing it "in house". Plasma is not that far behind laser in competent hands.

There are some excellent magnetic clamping/positioning plates "out there" that are quick to use either "as is" or in conjunction with a jig or fixture and they are not all that expensive either. I have some and I swear by them.

I only use my plasma cutter on a very "occasional" basis.

Mosside
10-05-2007, 06:47 AM
I've seen them in the KBC catalog. On a small press I think annular cutter would be a little faster than a drill untill it got dull. I've never had to sharpen one so I'm not sure how hard that is.

Doug

torker
10-05-2007, 09:09 AM
Glad I asked! Yes I'd like to have an Ironworker with a big punch. I've sat in front of one of them for far too many hours. Has to be the most boring job in the world...til now. As a shop owner looking at it all of a sudden a punch press looks very exciting. But that won't be happening for awhile. I have to be carefull what I rush out and buy.
You woke me up with the plasma idea. I'm actually buying a newer, heavier machine that will sever 1". I'll just keep my old Lincoln for a spare. After six years of abuse it finally broke down and is in the repair place in Cowgary.
The ring/jig...at first I wondered how we would center this little contraption then it dawned on me that all one would have to do is machine a plug with a sharp center on it that would drop in the jig and would locate a center punch mark. Now I'm thinking about a minute for each hole. I'm liking that idea.
Back to the annular cutter idea, I'll check out KBC then. With the mag drills on heavy structural iron I've drilled several hundred holes with the same cutter. You have to use coolant. I'm sure my drill press has a lot more power than a mag drill so it may work out.
These annular cutters can be sent out for sharpening for a reasonable sum. A pain though.
Willy....my mill/drill would work if I could slow the spindle down to at least a blur. It's far too fast for the larger drills that they say you can use on them. Plus I generally have something setup in it...it's one of my most used machines.
Oh how I'd like a big radial drill. We used to stack plates up as high as the drill would go through then stand and watch the big brute spit out little steel culverts...a thing of beauty!
A fellow here was kind enough to point out to me that he recently bought a 6' radial drill for $50 and that it was NOT for sale. Thankyou!
Thanks guys! I have a couple of options now. I'm liking the plasma idea.
Russ

DR
10-05-2007, 01:11 PM
KBC has good prices on annular cutters. Be aware they aren't up to the quality of American made Rotobroach brand though.

We had a job using 2" cutters in 1/2 x 4" angle iron. It was a tough partial hole cut, Rotobroaches would do about 50 holes if careful. Switched to KBC brand and the first 2 broke on first cut. This was in a CNC mill so conditions were identical.

Since KBC's were a third the price we tried backing way off on feed and had better luck. All in all, considering the lower price the KBC were a better deal even with the slower cutting.

I would say in less then ideal conditions/setup none of the larger annular cutters will last long. The smaller diameter ones may not be as fragile.

BTW, KBC replaced the two broken ones free of charge. In general I've had good luck with them. Same free replacement on a broken boring bar.

platypus2020
10-05-2007, 02:26 PM
I use annular cutters in a drill press all the time, Jancy, and Hogan both make an arbor either MT#2 and MT#3, and R-8, so they can be used in a mill. They cut very fast and don't require massive force to cut the holes, and they leave a great finish in the hole.

Jack

fishfrnzy
10-06-2007, 09:42 PM
Russ,

I have three customers that are using the hougen or champion annular cutters. They told me it was 500-700 with the coolant thru the spindle center supposed to be impotant for floating out the chips. One reports 40 seconds to drill 1" dia in 3/4 plate, was at 4 mins. Another does 1-1/2" holes in 1" th T1 plate in 3-4 mins with old(looks like the twentys) drill press, he says its about 6-7x faster than with regualar drill and stepping up. Hope this helps.

torker
10-07-2007, 09:06 AM
Thanks guys! OK, I have to know this...how do you pop the slug out of the cutter if you are using an adapter? The mag drills I've used all have the pilot pin in them that pushes the slug out as you raise the quill. I'm not quite seeing how you'd do this with an adapter on a drill press.
Thanks!
Russ

DR
10-07-2007, 02:53 PM
Thanks guys! OK, I have to know this...how do you pop the slug out of the cutter if you are using an adapter? The mag drills I've used all have the pilot pin in them that pushes the slug out as you raise the quill. I'm not quite seeing how you'd do this with an adapter on a drill press.
Thanks!
Russ

As I recall, usually the slug just dropped out with the 2" ones we used, no pilot or ejector. We did verify it wasn't still there before going on to the next hole.

Regarding rpm of the cutters.....I would keep it to around 75 sfm with lubricant and less without. For reference, a 3/8" cutter at 1000 rpm is 100 sfm. So, a 7/8 should be in the 350-400 range or less. Do not run them too fast!!!

BTW, we have a Hogan adapter with 1" shank and a sleeve type side inlet coolant. The inside of the cutter fills with fluid until break through. Slug and part are barely warm to touch.

Timleech
10-07-2007, 03:26 PM
Thanks guys! OK, I have to know this...how do you pop the slug out of the cutter if you are using an adapter? The mag drills I've used all have the pilot pin in them that pushes the slug out as you raise the quill. I'm not quite seeing how you'd do this with an adapter on a drill press.
Thanks!
Russ

Some MT adapters do have provision for a pin, or a built-in pin. Trouble there is it won't work with long cutters. I've got a home made one (from a drill shank) which has no provision, it can sometimes be a pain getting the slugs out.

Tim

platypus2020
10-07-2007, 06:30 PM
Thanks guys! OK, I have to know this...how do you pop the slug out of the cutter if you are using an adapter? The mag drills I've used all have the pilot pin in them that pushes the slug out as you raise the quill. I'm not quite seeing how you'd do this with an adapter on a drill press.
Thanks!
Russ

The MT and R-8 adapters have the previsions for the spring loaded center pin, to eject the slug, I do thousands of holes a year, and never have a problem.

According to Jancy and Hogan, the magic number is 382 rpm for a 1", all you do is divide the diameter into 382 to get the correct rpm. (example 382/.75= 509 rpm for a 3/4" cutter)

Jack