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gunsmith
08-19-2005, 07:22 PM
This was a first for me. I purchased an "annular cutter that was too cheap to resist on ebay. Not disapointed. What a way to cut large holes in steel. Right through 1" plate and never a moan. A 2.5" hole in just over a couple of minutes. Fantastic. There will be more of these in my future. Are they made in different grades? I plan on cutting a lot of stainless.

bobbybeef
08-19-2005, 08:19 PM
I use a bimetal circular hole cutter to cut circles in 1/4" brass sheet to make clock wheels. works a treat. the biggest I have used in a minimill is 3 and a 1/2".Real slow on the speed. I reckon about 80 rpm.
I take the guide drill out of the bimetal holder because it is too big for the clock spindle.The brass sheet is clamped down on a piece of plywood real tight.Very slow feed. I guess I could go higher on the speed and feed but why wreck a good job for two minutes.Have not tried it on steel yet but dont see why it would not go there.
Regards,
bobbybeef.

panchula
08-19-2005, 08:51 PM
Annular cutters are a great thing. One brand I'm familiar with is the Hougen Rotabroach.

http://www.hougen.com Made here in Michigan.

-Mike

[This message has been edited by panchula (edited 08-19-2005).]

wierdscience
08-19-2005, 09:09 PM
Have been using them for years.One tip I can give you is keep them cool.When they cut they heat up,when you stop cutting they cool off quick,if you don't get the slug out quick sometimes they will contract and crack.

In the lathe I stick a coil spring in the inside so when the cut is finished the slug pops out.

Oh,and they are also made by the good folks at Bison,KBC lists them fairly reasonable.

DR
08-19-2005, 09:35 PM
Annular cutters are great if you have a rigid setup. Those 3/4" diameter, short shanks aren't the easiest thing to hold securely. I sprung for the special 1" diameter arbor made for the purpose.

I've boughten the Polish Dolfa (sp?) brand from KBC. Not as good as the real thing, Rotabroach, but the price is right.

We used to do a job with a bunch of 2" holes in 3/8 x 4" angle. After going through a couple $164 Rotobroach's I tried the Polish import. Broke the first one, when I re-ordered from KBC the guy asked how I liked them. He replaced the broken one and gave me another, no cost.

That's been my experience with KBC, they've replaced any imported tooling that's broken prematurely.

gunsmith
08-20-2005, 07:05 PM
Ya a thumbs up for KBC. I've had no problems with them either. Weird: thats a good idea with the coil spring. The one I purchased has a 1"x 2" long shank and I made my own chuck for it to operate in my turret lathe. I still can't get over the ease that it cut heavy steel. It is definatly far superior to any and even the best hole saws. I do have to check out the requirements for stainles however. I have seen that "Hougen" brand mentioned. Thanks for the site, they probably have the answers I am looking for.

Weston Bye
08-20-2005, 07:57 PM
"Annular cutters are a great thing. One brand I'm familiar with is the Hougen Rotabroach.

http://www.hougen.com Made here in Michigan."

Another vote for Hougen. Back when I was building a lot of control panels and wiring machine tools, I used their hole saws in a Milwaukee Magnum. Drilled literally thousands of holes over a period of 18 years.

Wes

wierdscience
08-20-2005, 10:13 PM
<font face="Verdana, Arial" size="2">Originally posted by gunsmith:
Ya a thumbs up for KBC. I've had no problems with them either. Weird: thats a good idea with the coil spring. The one I purchased has a 1"x 2" long shank and I made my own chuck for it to operate in my turret lathe. I still can't get over the ease that it cut heavy steel. It is definatly far superior to any and even the best hole saws. I do have to check out the requirements for stainles however. I have seen that "Hougen" brand mentioned. Thanks for the site, they probably have the answers I am looking for.</font>

Stainless they work fine,I do run the coolant mix a little heavier on the oil side like 20:1.I use them on a regular basis in the mill drilling recessed brnah holes that later get half couplings welded in.Hougen's are better than Bison,just pricey.If you have a B&D outlet store neaby,check the're discount bin.I found a 2",1-13/16" and a 1-15/16" x 2" cut for $20 each.Marked B&D indutrial,but made by Hougen.