Annular cutters/Rotabroach?

[Jason280]

I picked up a few Hougen 1/2" Rotabroaches, but don't know much about these style cutters. I know they are designed to be used with Hougen mag drills, but I am really more interested in how they compare with standard twist drill bits. As it stands right now, I won't be able to use them with my drill press until I turn down an adapter, but curious if they would be worth the effort. I still would have to pick up a pilot, but they're not too expensive.

Are they worth fabricating an adapter? I drill a decent amount of 1/2" holes, but have a good supply of USA made HSS & Cobalt 1/2" bits.

 

[dr_clyde]

They are the cats *** for drilling holes on thick plate. That shank is for a mag dill, but you may be able to fit it in a Weldon style adapter. Hougen may sell an adapter.

 

[wvrrcarknocker]

We use them in a mag drill to drill holes in truck frames for various upfitting tasks. They work well, and last a good long time, several hundred holes at least.

 

[Strouty]

I would not make an adapter, let me get you my address.

 

[sk farmer]

they will drill circles around a standard drill bit, pun intended.

if you only have a few you may be as well to sell or trade them rather than make an adapter. commercial ones can be had if need be as well.

 

[Strouty]

All kidding aside, Dr_Clyde is right. A weldon shank adapter should work for them. They spin at pretty slow speed regardless of the size. My mag drill is a single speed and I can cut up to 2" I think. If you make an adapter, you need to have a provision for the center pin, it is used to center the bit and to push the slug out. The weldon adapter should be set up for it. You will need to get a center pin if you don't have one. I guess you could make something up, but I don't think they are that pricey.

 

[JoeFin]

I my opinion - not worth the effort to build an adaptor

Yep they are Great in a Mag Drill when your up on the steel and need to punch some holes.

But if your in a SHOP as in drill press then why do you have dull drill bits? I have a Cincinnati Tool & Cutter Grinder and my drills, and every thing else that cuts is sharp. Sharp enough to punch 1/2" holes through 1/4" as fast as you can load the drill press.

But now take a second look at those Annular cutters. Real Nice hard Cobalt Steel - the type that needs a lubricant to keep them cool. Too hard to file and too complex to sharpen on the bench grinder.

No - I'll take sharp bits for the drill press over those any day

 

[fnieto]

Annular cutters work well on mag drills and milling machine. If you decide to utilize them on a drill press you will need to secure the work piece firmly. The cutters will break if the work piece slips. The holes produced are perfect with these cutters. Ebay had some weldon adapters for around $80-100.

Lubricant is a must (cutting fluid).

 

[Worsedog]

I have a set that will go only a 1/4" deep, but they are the cat's ***. Perfect holes with light feed pressure and they make awesome spot weld cutters as well.

 

[Jason280]

Interesting. I don't mind fabbing up an adapter, seems like they would be fairly useful...still need to order a pilot if I am going to keep them, though.

 

[dr_clyde]

My only concern would be RPM. They don't need to turn fast, and your drill press may not have the available lower RPM to properly cut.

 

[Strouty]

The mag drills spin as low as 250 RPMs and I have seen some close to 700, but that was a drill with more than one speed.

 

[astroracer]

I've used the short ones in my drill press for years. Making holes in sheet metal to 1/2 plate. The work DOES need to be constrained well, especially the heavier stuff. I can't remember what speed I use. I'll have to look.
Mark

 

[Jason280]

I'm pretty sure my drill press will drop down to around 220-300 rpm's, so speed shouldn't be an issue.

 

[Mohawk Dave]

Ever since I went to annular cutters, I really don't use drills anymore. Cutters kick so much ***.

If you have a DP that is HD enough, buy the Hougen adapter....http://www.ebay.com/itm/Hougen-1101...540?pt=LH_DefaultDomain_0&hash=item3aa89942b4

Just make sure you use cutting oil or the Hougen slick stik stuff.

And there is 2 major platforms of cutters. the 12xxx series, and the 17xxx series. You have the 12xxx series which is more "common". As do I.

You mention you have good drills, however, a drill does not make a perfectly round hole, which is why reamers are present. (We're talking 100s/1000s/of an inch). However, the cutters cut round everytime. and have less surface on the OD to drag, and they cool better.

 

[Jason280]

Thanks for the link. I found one of those a couple days back, but figured I could turn one down on the lathe for a bot cheaper. Any suggestions on a good cutting fluid?

 

[Mohawk Dave]

Thanks for the link. I found one of those a couple days back, but figured I could turn one down on the lathe for a bot cheaper. Any suggestions on a good cutting fluid?

I don't know if I'd turn one myself. Reason being is the 2 notches need to be perfect otherwise you won't be concentric. You can try, but even if you are off a little and can not tell by eye or feel, it will kill the cutters in a hurry.

As far as fluid goes, I bought the Hougen slick stick, but the old timer that I buy my mag drills from says he's never burned a cutter and he uses anything...cutting fluid if it's around, if not oil, trans fluid, WD-40, whatever, he just said the cooler the better.

He's been doing big structural steel for decades and KNOWS what he's talking about.

 

[dr_clyde]

My go to cutting fluid is TRIM E206. Very versatile, I keep it in a squirt bottle, as well as in the saws, lathe, and mills. I'd use that, or some other comparable soluble oil. You're looking for primarily coolant, with some cutting oil, not the other way around.

 

[Jason280]

Score! Life is good....

http://www.garagejournal.com/forum/showthread.php?t=292348

 

[DekeT]

http://www.victornet.com/alphabetic/Annular-Cutter-Holders/1861.html