Welding Tips and Tricks

I'm looking for a better solution when running hole saws on a mill or large drill press. Typically 1" to 1.5" hole saws for cutting copes into tubing of the same size range and wall thicknesses of about .060" to .083", so somewhat on the thin side. Chucking up a typical hole saw arbor introduces a fair amount of error and/or chatter.

So... anybody know of a good solution to better use hole saws on a mill? Perhaps a more rigid arbor/mandrel setup that can allow the hole saws to mount on a beefier mandrel that can then be slid into a collet?

Also, does anyone have a source for hole saws with a higher tooth count. The TPI on all hole saws I can find is really a bit low for use on tubing. You'd think they would make them in different TPI, but I can never find any.

How exactly are you chucking up the hole saw? Standard drill chuck?

Last I checked years ago, Starrett was the only source for high tooth count hole saws. Pricey. How many teeth do your current hole saws have? What RPM you running them at? Ive used standard bimetal hole saws on 16ga tubing, but generally have to run them fast, due to said low tooth count, which is about 16-18 along the whole circumference.

I haven't notched tubing, but I have drilled into tubing using a holesaw in a mill. Of course the tube has to be very secure, don't recall rpm but maybe 200 - 300 and plenty of coolant and slow feed rate.

Back on topic, maybe something like this would help, and not too expensive at Trick Tools

Oscar wrote:How exactly are you chucking up the hole saw? Standard drill chuck?

Last I checked years ago, Starrett was the only source for high tooth count hole saws. Pricey. How many teeth do your current hole saws have? What RPM you running them at? Ive used standard bimetal hole saws on 16ga tubing, but generally have to run them fast, due to said low tooth count, which is about 16-18 along the whole circumference.

Yup, just a beefy jacobs chuck. Don't know the exact tooth count (already left the shop, otherwise I would find out), but they are the standard Lenox bimetal hole saws, so a fairly aggressive TPI. Running them between 60 and 100 RPMs. I'll try it out running faster.

I just know it could be so much better....surprised there are not more accessible solutions for this since it seems a lot of folks use hole saws for tubing copes, and it's generally known to be a PITA. Might try to make my own hole saw mandrel that can fit directly into a collet and with a way to more rigidly mount the hole saw to the mandrel.

LtBadd wrote:I haven't notched tubing, but I have drilled into tubing using a holesaw in a mill. Of course the tube has to be very secure, low rpm and plenty of coolant and slow feed rate.

Back on topic, maybe something like this would help, and not too expensive at Trick Tools

I've used those, and they're not great. Haven't used that exact one from trick Tools, but a couple others that were the same exact concept.

The tubing is quite secure in the mill vise sandwiched between two long machinist's V blocks. Rock solid. The weak link in the setup is the hole saw mandrels.

Yea standard Lenox hole saws are 6-8 tpi, same as mine. Try running them about 300-400 RPMs with a thick cutting oil, at least 40wt.

You can always make your own. I had contemplated making my own, but the project i was gonna use them on got put on hold. It was something like 0.028" wall.

If you have any good swap meets near you, or used machinery / surplus dealers, see if you can pick up some used end mills for the sizes you need.

If you have to plunge cut, there's annular cutters like the 12,000 Series here;

https://www.hougen.com/downloads/Hougen ... _Chart.pdf

The discount tool outfits sell similar for magnetic drills, etc, but you know where they'll be made................

But then the low tooth count could be a problem with that style.

kiwi2wheels wrote:If you have any good swap meets near you, or used machinery / surplus dealers, see if you can pick up some used end mills for the sizes you need.

If you have to plunge cut, there's annular cutters like the 12,000 Series here;

https://www.hougen.com/downloads/Hougen ... _Chart.pdf

The discount tool outfits sell similar for magnetic drills, etc, but you know where they'll be made................

I had thought about end mills or annulars, but since I would need 4 or 5 different sizes, and most of them over 1.25", the cost was a turnoff, especially since copes tend to be hard on tooling. I'd hate to destroy a $100 tool after only a handful of cuts. But if it's a good solution, then probably worth it. I should pick some up just to test it. Might also be able to just bill the customer for the tooling if it makes the job easier/faster/better/cheaper and they agree to it.

Shell mill or annular cutter, Spartan. Sure, they cost a good deal more, but they cut like butter and can be sharpened. Decent HSS cutters are not that expensive. High quality hole saws that are carbide tipped cost nearly as much.

cj737 wrote:Shell mill or annular cutter, Spartan. Sure, they cost a good deal more, but they cut like butter and can be sharpened. Decent HSS cutters are not that expensive. High quality hole saws that are carbide tipped cost nearly as much.

This^^^^

I would shop on Ebay for used mills in good shape. A Shell mill could work but not ideal for your mill, IMO, depends on the holder you have. This is where a horizontal mill rocks...

The hole saw will work, but I personally wouldn't use it, I would use it on the drill press. In that regard you won't get worse results on the mill with a hole saw, however, you won't get the precision a mill provides by using it, and if you bind something hard you may wack the mill out of tram.

The mill you just got is not ideal to cope tube, because it requires a pretty big cutter with long flutes in order to cope a 1-1./2" tube. Not trying to talk you out of it, just that the mill you got will have a difficult time holding rigidity with a 1-1/2" cutter.

I would just use a hole saw in a drill press and use an angle grinder to clean it up, you can get clean fit ups with it.

That said, couldn't hurt to try the hole saw in the mill.

Lastly, think about making one of those fixtures that will allow you to use a hole saw to cope pipe, check the one at Eastwood, you could probably make one yourself or just buy it, I think they cost about $300. I would probably use the hole saw in a drill press before the mill if you already have the hole saw. My $0.02.

EDIT: like this:

https://www.eastwood.com/professional-t ... tcher.html

TraditionalToolworks wrote:

cj737 wrote:Shell mill or annular cutter, Spartan. Sure, they cost a good deal more, but they cut like butter and can be sharpened. Decent HSS cutters are not that expensive. High quality hole saws that are carbide tipped cost nearly as much.

This^^^^

I would shop on Ebay for used mills in good shape. A Shell mill could work but not ideal for your mill, IMO, depends on the holder you have. This is where a horizontal mill rocks...

The hole saw will work, but I personally wouldn't use it, I would use it on the drill press. In that regard you won't get worse results on the mill with a hole saw, however, you won't get the precision a mill provides by using it, and if you bind something hard you may wack the mill out of tram.

The mill you just got is not ideal to cope tube, because it requires a pretty big cutter with long flutes in order to cope a 1-1./2" tube. Not trying to talk you out of it, just that the mill you got will have a difficult time holding rigidity with a 1-1/2" cutter.

I would just use a hole saw in a drill press and use an angle grinder to clean it up, you can get clean fit ups with it.

That said, couldn't hurt to try the hole saw in the mill.

Lastly, think about making one of those fixtures that will allow you to use a hole saw to cope pipe, check the one at Eastwood, you could probably make one yourself or just buy it, I think they cost about $300. I would probably use the hole saw in a drill press before the mill if you already have the hole saw. My $0.02.

EDIT: like this:

https://www.eastwood.com/professional-t ... tcher.html

Good advice for sure. I'm leaning towards the mill over the drill press, as you can probably imagine, due to the precise maneuverability of the tubing, especially with the DRO. It just makes positioning so easy. It's also nice to have the big, long table to reference off of for tubes that are already bent in order to square up the clocks between the copes on each end.

I'll play around with it all and see what works. But the drill press just seems so sad now that I have the mill.

Spartan wrote:Good advice for sure. I'm leaning towards the mill over the drill press, as you can probably imagine, due to the precise maneuverability of the tubing, especially with the DRO. It just makes positioning so easy. It's also nice to have the big, long table to reference off of for tubes that are already bent in order to square up the clocks between the copes on each end.

Agree 100%, just don't be too surprised if the hole saw is not as accurate as you would like, it should be more accurate than a drill press, but a hole saw in general is not a precision cutter and was not intended for a mill, AFAIK. I have a DRO for my Deckel I bought, but haven't put it on yet, I need to do that.

Spartan wrote:I'll play around with it all and see what works. But the drill press just seems so sad now that I have the mill.

One thing that may or may not make a difference is how long the quill is on your mill. My Deckel mill has a very small quill, like 2" so I use the Z axis feed more often than not for drilling. I often tap by hand on the mill, using the mill as a guide. I normally don't power tap on my Deckel, but have on the Nichols as it has a head on dovetail ways that slides with a lever, really nice for tapping.

I have a tapping head for my drill press also. I don't mind the drill press, very handy machine.

Coping tubing is hard on any cutter especially doing stainless - anything over about2" I usually plasma cut but under that I do on the mill - usually use RotaBroach cutters as they are more rigid but have used hole saws - I never had any luck using a chuck & standard hole saw arbors as they flop about all over - I simply made up an arbor for the mill that has2 protruding drive pegs & is threaded internally so you bolt the cutter to it - works OK - I never found decent high TPI cutters but have a variety which are vary pitch & they are fine on roll bar stuff - not great on exhaust though.

I've seen some "new" type of rotary cutters on FB. Don't know enough about them to say Get'em. From the video they seem to be the nuts for makin holes in flat stuff. Can't right now tell you the name.
how about trying to wake up Zank,,,he messes with tubing all the time.

noddybrian wrote:I simply made up an arbor for the mill that has2 protruding drive pegs & is threaded internally so you bolt the cutter to it - works OK -

That's EXACTLY what I was thinking about doing. May be the best option. The tubing all needs to be TIG welded, so plasma cutters and grinders are being avoided, at least for now. We're getting by...I just know it can be better, so I want to get there.

BillE.Dee wrote:I've seen some "new" type of rotary cutters on FB. Don't know enough about them to say Get'em. From the video they seem to be the nuts for makin holes in flat stuff. Can't right now tell you the name.
how about trying to wake up Zank,,,he messes with tubing all the time.

You've piqued my interest here, BillE.Dee.