Tubing notcher

Hi Bruce,

Funny meeting you here!

I've tried all of the above at one time or another. Not on stainless - but 4130.

The only one that really works well is the end mill solution.

I finally decided to do them by hand (grinding wheel) with the aid of a computer program called WinMitre.

This program prints out a cutting template for the joint. Cut out the template and mark the tubes to be trimmed and go at it.

Problem I ran into was how to mark the tubes so that the heat from grinding didn't destroy the marks.

Finally transfered the common patterns to thin aluminum sheet and used one of those vibrating markers to etch the cutting lines on the tubes. That works ok, but it's a pain to make hard tooling for a bunnch of different joints.

FWIW...

Richard

A simpler solution.

Check the section of Pipe and Tube Connectors.

I've got a couple of pipe layout programs that work all right but I wanted something a bit more automated. I'll have about 20, more or less, stanchions that will need to have a fish mouth ground on the top end, flat on the bottom and a hole through them half way up, and they will have to be pretty close to the same length.

I've ground my share of tubing (had an old apprentice master that reckoned if he could see light through the tubes they needed more filing :-) and really don't want to do that any more.

There is one other device I've seen here, but not examined closely. It appears to be a horizontal belt sander with a guide holding the tube into the front roller which seems to be removable, I assume to change tubing sizes. How well it works I don't know but the knife makers all seem to use belt sanders so they must cut all right. (and I've got an old belt sander I never use =:-)

I was really hoping somebody was going to say, "Heh! Get yourself one of those $35.00 Harbor Freight dingus' and you'll be able to do that job in ten minutes." Been hoping some rich relative would leave me a million dollars too.......

Bruce in Bangkok (brucepaigeATgmailDOTcom)

Had a look at their page and it all looks like interior railings. This stuff is for a boat and has to look "yachty". Maybe don;t make sense but that is the way they are.

Bruce in Bangkok (brucepaigeATgmailDOTcom)

The hole saw units are inexpensive and do a nice job. Downside is that they are slow, consumable costs are fairly high (tear up or wear out the hole saws), and modifying a cut for the best fit is back to grinder/file. Haven't tried these on stainless but you will need a GOOD grade of hole saw.

The belt sander units work fine, more money than the hole saw variety. You need a hard rubber mandrel about 1/8" smaller than the tube it will mate to. If you are doing 1" rails, this gets to be a fairly small mandrel. You can adjust the fitup with ease.

Using a roughing cutter (don't use a regular 2 or 4 flute mill!!) in a Bridgeport is nice.

The notchers work fine but they leave some square edges at the tips of the fish mouth. And they don't like odd angle fitups where the depths and shape vary from one side to another.

Winmiter and similar programs work fine for one offs but get fussy for these small tubes.

We do small race car frames with 1" and 1.25' tube. My guys have switched from the Bridgeport to the hole saw method, mostly because the Bridgeport is 200' away from the fab area and there are some access issues. Another local team uses the belt sander setup in a shop built rig. I've seen the notchers used at a high volume tube fabrication plant, great for heavy wall tube/pipe where the thick wall lets you be sloppy with fitup. For thin wall notchers take some time to get the setup just right, not good for one offs.

Ya pays your m> I'm looking at a project to install 316L stainless hand rails on a 35

There ought to be a free lunch somewhere. =:-(

The thing is that for boat rails you want either the smallest bead you can get, with minimum ripple, in which case you can get by just hitting it with a soft buffer and clean the color off the bead, but if you do larger beads then you have to grind them into smooth fillets and then polish them. It's gotta be pretty!

Are you using low carbon or something like 4130 for chassis? And how many cuts can your guys get out of one hole saw?

Bruce in Bangkok (brucepaigeATgmailDOTcom)

I hate to say it but I suspect that the hole saw is going to be the way to go. It was quite a while ago that I did my apprenticeship and had hoped that some of this rocket science you're always hearing about would have rubbed off on tubing fit up by now. :-)

Bruce in Bangkok (brucepaigeATgmailDOTcom)

wrote in message news: snipped-for-privacy@4ax.com...

yeah, wow, good luck. i bought a harbor freight tubing notcher and i thought it sucked so bad i sent it back, haven't had the balls yet to cough up the one hundred and sixty something bucks to get the "ol' joint jigger" version.

i'm hoping it's better than the harbor freight one. i was afraid the harbor freight and ol' joint jigger are made on the same line in the same factory in china. i called ol' joint jigger and they say there's roller bearings in their arbor, whereas the harbor freight version is just a plain bearing. there was too much play in the arbor and so the hole saw kinda chattered all over the place on the tube. i suppose it also was a combination of not having a hole saw with fine enough teeth and my impatient feed speed. when you said stainless *I* shuddered, i'd think stainless in a harbor freight tubing notcher would be a merciless nightmare but then again i was trying to cut a larger diameter tube with a larger hole saw, maybe it works better w/ smaller diameter stuff. good luck. i posted this message because i wanted to say, kind of as a joke, recently i saw a program on tv about the harley davidson factory in milwaukee, they have a computer controlled LASER cutter for cutting PRECISION fishmouths on the ends of their tubes, impressive! it's fast and accurate. (much envy) (the idea was that their new V Rod design has exposed tubing so the welds have to be PRETTY.)

b.w.

btw, bruce in bangkok huh? jeez. hope life there is good for you. good luck w/ your project.

-snip-

oh, btw, i saw someplace, sorry i can't remember where, hole saws with very fine teeth, not the common "home depot" version (you prolly don't have home depots in thailand) in a aircraft builders supply catalog. they looked like they were milled not stamped. maybe someone here knows where to get GREAT (not just "good") quality very fine toothed hole saws to fit on a tubing notcher.

b.w.

Now that is the sort of progress I'm looking for. Push the button and ZAP, a perfect fish mouth joint. Wonder what the shipping to Thailand would be..... =:-)

Bruce in Bangkok (brucepaigeATgmailDOTcom)

I've seen mention of these also. I believe that they are HSS too. Of course, if there are any in this part of the world they are in the back room of some Chinese hardware store and Grand Pa just died and the kids don;t know where anything is.

I'm being a bit facetious here but I was actually in a hardware shop, last week, where this had happened. Looking for a HSS tool bit, and was told that they knew that they had some but couldn't quite put their finger on them right now and could I come back in a couple of days.

Bruce in Bangkok (brucepaigeATgmailDOTcom)

Watched a really nice tubing cutter at work at a trade show last year. Sounds like it's just what you need.

Couldn't have been more that a million or so dollars.

But it came with a couple days of onsite training included!!

Me too!

Not in this lifetime.

Not unless I want to find a way to make it pay....

Cheers Trevor Jones