# Annular Cutter Fail



## Farmer Rod (Jul 9, 2014)

Hey All-

Just getting started here. Looking to build up some rad steel bikes. 
I read all the FAQ's, all 36 segments of Jay's wwtp saga, and scoured around the site quite a bit. Super good information. I hope that limits my posting of redundant questions. Having said that I have a question.

Today I was attempting some mitering and ran into an issue that I haven't seen come across this forum yet. Hoping someone could shed some light, or point me in the direction if I've missed it somewhere.

Trying the mill / annular cutter method. Using a mill vice and 3" cubes of Red Oak bored out for tubing blocks. Everything's solid, rigid, and lined up nice.

Using a (new) 38.1 cutter, and attempting to miter my 28.6 ST. 

The issue is that I'm getting about 3/4 of the way through the cut and the tubing wall catches on the cutter and folds in.
I've got it on the slowest (I think) rotation speed and manually applying downforce at an excruciatingly slow rate.

Thanks in advance. First post, first frame here. Looking forward to years of bicycle building related internet blabbermouthing with you folks.

Cheers.


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## Walt (Jan 23, 2004)

That type of cutter (or an end mill) does not tend to work well on thin tubing. Get a nice generic hole saw (pick your favorite/cheapest brand, or get crazy and try to find the highest tooth count you can - in my experience the cheap ones work fine) and get some arbors from Paragon and you will be golden.

-Walt


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## Farmer Rod (Jul 9, 2014)

Awesome. Thanks a bunch.
I'm on it.

Funny though isn't it? I would (did) think a super stiff precision cutter that doesn't oscillate would be better. 
Glad to hear I can (and should) go the cheap route. 

Thanks again.


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## Walt (Jan 23, 2004)

Cutting metal is so weird. Every metal is different. Every wall thickness and shape is different. What works on one thing will destroy another... I agree that intuitively, I think a cutter like you're using should be great. IRL, not so much. That's why hanging around with old crusty machine shop guys can be a gold mine of info. There's a trick and a technique for everything - for cutting bike tubes it's pretty much hole saws.

-Walt


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## BungedUP (Aug 18, 2003)

I highly HIGHLY (HIGHLY - did I say that?) recommend purchasing Starrett 6-pitch holesaws. They really work a lot better, with much longer longevity, than most other holesaws I've tried.


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## Farmer Rod (Jul 9, 2014)

Cheers, Thanks!


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## afwalker (Apr 26, 2012)

Sometimes too you'll be making a cut on a tube and the tube will be too wide to fit all the way inside the cutter. I use aircraft shears and snip through the tube to finish the cut.
cheers
andy walker
www.flickr.com/photos/afwalker50
Walker Bicycle Company | | Walker Bicycle Company


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## Farmer Rod (Jul 9, 2014)

That's with a hole saw Andy?

The tubing bottoms out inside the saw cup, you trim it for clearance.. Got it.
Thanks man.


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## Farmer Rod (Jul 9, 2014)

It's funny Walt. Me and a group of machine shop guys (and a tool shop owner) came up with this method.
Turns out we should've just asked a frame builder.

Lots of variables in the fab industry!

R8/drill chuck ordered, R8/annular cutter holder in the drawer.


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## Walt (Jan 23, 2004)

Obviously your friends aren't old/crusty enough! 

The Paragon R8 arbors are nice and stiff if you have trouble with the drill chuck method.

-Walt



Farmer Rod said:


> It's funny Walt. Me and a group of machine shop guys (and a tool shop owner) came up with this method.
> Turns out we should've just asked a frame builder.
> 
> Lots of variables in the fab industry!
> ...


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## dr.welby (Jan 6, 2004)

Some of the El Cheapo hole saw arbors are just a hair over 1/2" in diameter on the portion above the threads. A quick pass on the lathe and you can grab them in a collet instead of using the skinny part sized for a hand drill.


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## Farmer Rod (Jul 9, 2014)

Cheers, thanks for the tip.

Currently I plan to use an R8/ Drill chuck in the mill, with a Paragon arbor.

Oh dang. Those Paragon arbors have a 3/4" diameter shaft don't they. Think the chuck I just ordered is 5/8". Might be making my own arbor (or modifying one), until I can swing a collet.
Mill is new, and no real tooling yet, just trying to piece it together as I need it.

Thanks!


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## Fort Colin (Dec 1, 2013)

Instead of the drill chuck, why not just use a 3/4" R8 Collet in the mill?

I just got my Logan Lathe set up with 5C collet system. My Lenox arbors would fit into the 3/4" 5C collet and I now have some of the long Paragon ones to do the cut on the chain stays for the BB.


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## smudge (Jan 12, 2004)

If your mill has an R8 taper, do yourself a favor and get a 3/4" collet for it. It's cheaper than a drill chuck and will hold that arbor MUCH more securely than a drill chuck. Also, if you're using a 2-part chuck with a Jacobs taper, there's a pretty high likelihood that it'll separate at some point which won't be fun. 

Seriously, for best results, give yourself the best possible chance. Fine tooth hole saws, 3/4 collet and Paragon arbors. FYI, I use 1.25" arbors that I made in house that work with 1.25" 40 Taper endmill holders and they're markedly noticeably stiffer than the 3/4" arbors. I'm not saying they're necessary, but they're definitely noticeable, especially if you're in a situation where you have to hang them out.


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## Farmer Rod (Jul 9, 2014)

Great info, thanks guys.
Drill chuck already on the way, spot in drawer cleaned out for it.

I have some ordering to do.

In terms of the Paragon Arbors, when would you use the longer ones?


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## Fort Colin (Dec 1, 2013)

In general, the less tool you have hanging out of the mill, the less the tool can wander and flex you will have.

I would go the long arbors when you can not complete the cut with the short arbor. I can use a short arbor if I cutting tubes for the main triangle, but I have to go to a long arbor to get through both chainstays in one pass on my setup.


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## TrailMaker (Sep 16, 2007)

And another thing...

I always use the fine down feed wheel on the mill. The regular quill down feed is far too coarse and fast, and the saw teeth will grab and auger into the tube, gnarring it to smithereens or hammering the hole saw. Just no way to get a reliable cut that way. I don't use the slowest motor speed either. My lowest speed is 290, but that is too grabby. I use 5-800rpm. VERY light feed, let the teeth do the work, nice and patient. No problems.


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## smudge (Jan 12, 2004)

Farmer Rod said:


> Great info, thanks guys.
> Drill chuck already on the way, spot in drawer cleaned out for it.
> 
> I have some ordering to do.
> ...


Just because it's on the way doesn't mean it's the right tool. As I wrote before, if it's a chuck pressed onto a Jacobs shank, it'll come off eventually. Hole saws are in essence an interrupted cut which can sometimes mean that the cutter gets kind of a rotational shock...this is worst about 2/3 of the way through a DT/TT miter. A jacobs taper will eventually come off and it'll ruin your tube and probably the cutter. It's cheaper to just buy the damn collet now.

When I was (an instructor) at UBI, they used the long ones to cut the BB miter on the chainstays. Mark makes them out of cold rolled rod and they work OK when you're using soft steel and have your feed/speed dialed but they're often pretty wambley because they do have some runout and in some harder materials, or if your setup is wonky, you'll find out in a hurry that they're only 90% up to the task. Others use them when cutting the ST miter on seat stays if you have to cut them from the bottom up. Depending on the diameter of your quill and how much you stick out your stays, you might have to use a longer arbor.

You'll figure all this **** out on your own eventually, but you asked the question so it's in your best interest to follow the advice you're given here.


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## BungedUP (Aug 18, 2003)

smudge said:


> A jacobs taper will eventually come off and it'll ruin your tube and probably the cutter. It's cheaper to just buy the damn collet now.


While I agree that the collet is the better tool holder (by far), I have to disagree that a Jacob's taper cannot securely hold a chuck to it's arbor. In fact, I have found the opposite to be true - arbors with Jacob's tapers can be extraordinarily difficult to separate from tools, when they go together cleanly. Now Morse tapers on the other hand - they allow easy separation, and can separate unexpectedly. Not trying to be contrary...

-Peter


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## Farmer Rod (Jul 9, 2014)

Yes, thanks smudge... 

I stated in my post that I "had a spot in the drawer for it", meaning when it shows up it'll go in the drawer as I don't plan to use it.
And "I have some ordering to do", meaning I need to order a collet and some Paragon arbors.
Sorry if I wasn't clear on that.

I both appreciate all of your input, and am implementing what I'm learning here.



Thanks again.


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## todwil (Feb 1, 2007)

Alright 20 post and not one pic of carnage or failure!?


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## Farmer Rod (Jul 9, 2014)




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## afwalker (Apr 26, 2012)

I used to like the fine tooth hole saws from Ultra at Missouri Precision, but the factory shut down and there's only a few sizes left. Starrett's and Lenox are my prefered now.
Missouri Precision Tools, Inc.: Rockhard HSS BiMetal Fine Tooth Hole Saws
Folks speak highly of the Strawberry annular cutters, he has those made locally, but they are pricey,   Tube Cutters - Threaded
I've recently tried some Aircraft annular cutters and they work quite well, about $40 for the fine tooth ones. I modified my PMW arbors so they work on both ends by threading the other end on a lathe. Not an 1.25" arbor, but good enough and I'm liking the versatility. FINE TOOTH HOLE SAWS ATI ATI413 series hole saws | Spenro.com http://www.atitools.com/ATICatalog2010PDFs/ATI_Other_Products_2010.pdf
The long arbors help on angled cuts like seat stays. I use both lengths.
Notice the annular cutter is not deep enough to cut in one pass, have to stop in the middle and use tin snips to cut the top half of the cut, then finish cutting all the way through the tube. The cut is nice, but not much better than a plain hole saw and the tiny slivers are quite hard to get out of your fingers.







cheers
andy walker
www.flickr.com/photos/afwalker50


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## Farmer Rod (Jul 9, 2014)

Thanks Andy! Man, super good info. Really appreciate it.
Right now I'm using a Lenox and everything seems to be working fine.
Don't get those slivers on yer toilet seat! Ha!
Thanks again man.


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## lionrampant (Sep 28, 2010)

Does anyone have a feed rate that they suggest? I'm using hole saws with the Paragon Arbors. My mill doesn't have a manual Z-axis.


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## TrailMaker (Sep 16, 2007)

lionrampant said:


> Does anyone have a feed rate that they suggest?


S*L*O*W*! Experiment as required to find that golden pace.


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## Philbobb (May 12, 2014)

lionrampant said:


> Does anyone have a feed rate that they suggest? I'm using hole saws with the Paragon Arbors. My mill doesn't have a manual Z-axis.


On my CNC with a Starret straight 6 pitch 1-1/2" hole saw I run 150 rpm at 0.8 inches/minute. 200rpm does fine and I feel comfortable with 1in/minute, but it has a higher pitch squeal that annoys me.


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## huckxc (May 11, 2012)

Great thread!

Makes me want cut out a birds mouth from 12" pipe, using the blue book and oxy/acetylene.


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## Farmer Rod (Jul 9, 2014)

Totally. I haven't done that since pipe welding school.
I miss that smell!

That little blue book is priceless.


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## Farmer Rod (Jul 9, 2014)

Follow up...
It works, all of it. R8 arbor, Lenox hole saw.. Buzzes right through it, flawless.
Success! 

Thanks everyone for the info.


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