cutting a fishmouth joint

Googling around I see a variety of methods for cutting a fishmouth
joint.
One method is to use a cut-off wheel to make a 'V' cut, then grind to
shape.
What are they using to grind the 'V' to fit correctly? - Mike
Reply to
Michael Horowitz
Loading thread data ...
[...]
I use WinMiter too, and it works great. After I mark the fishmouth on the tubing with a Sharpie I use a 4.5" angle grinder to cut it out freehand. I wear a set of heavy gloves that have saved me numerous times.
I have a joint jigger clone that I bought years ago, but I burned up a bunch of hole saws and never really got it to work right. I've always wanted to try a lathe with a side mill to make precision fishmouths, but I don't have a lathe or know how to work one.
Dave
formatting link

Reply to
dlwilson
snipped-for-privacy@evcom.net wrote in news: snipped-for-privacy@o13g2000cwo.googlegroups.com:
Grant, I've found Winmiter to be a treasure. I don't bother cutting the curver on the template and tracing the edge on the tubes. I just cut a straight line across the peaks, tape it on the tube. and grind to the line on the paper.
Reply to
Ken Moffett
Well, just this morning I layed out 4 fishmouth joints on 2" pipe using one piece of paper, which I still own. This is schedule 80 pipe, it would take a good long time to grind to that line. I cut it out with a plasma cutter and used a grinder by hand to clean up. Biggest gap is maybe 1/32", fine for my purposes. I'll weld it with 6011 and then cover with 7018.
GWE
Reply to
Grant Erwin
Grant Erwin wrote in news: snipped-for-privacy@corp.supernews.com:
formatting link
.html
Another trick with Winmiter is to make a double fishmouth to join a pipe at a right angle to the intersection of two other pipes. I did this to make a patio-umbrella stand from 9' of 2" EMT. I cut two 3' pieces and two 1-1/2' pieces. The two 1-1/2' sectiones were fishmouthed on one end with the paper templates and the angle grinder. These were O-A welded, at right angles, to the middle of one of the 3' sections, to make an "X". This was layed flat to make the horizontal base. I needed to mount the other 3' section vertically from the middle of the "X". This required two fishmouths at 90 degrees from each other, because of saddling the four intersecting legs of the base. So I printed two templates, overlapped them on a light box (sunny window), shifted the top one 1/4 of the template-width to the left, and traced the lines from the bottom sheet onto the top sheet. This gave me a template for a double-intersect(?) fishmouth.
Reply to
Ken Moffett
I have "Winmiter" and "Tubemiter". Both these are freeware.
Pipe diameters can be entered into "Tubemiter" only by metric (mm) values.
"Winmiter" allows for input in either mm or inches.
However, "Tubemiter" uniquely allows for the WALL THICKNESS of the pipe. If "Winmiter" allows for this I'm not aware of it.
Yesterday I used "Tubemiter" for the first time to cut parts for an anvil stand out of 2 1/2" pipe.
I printed out a template, cut it out with scissors, and wrapped it around the pipe. I used a center punch to scribe the line in the rust on the pipe. Put it in the chop saw mitered to 45 degrees. Cut to the line. Changed the miter fence to a square cut. Cut of the "points" of the cut by just "eyeballing" it.
To my surprise, each of the three fish mouths was darned close to a perfect fit. To my even greater surprise, all of the tripod legs were of the same length. Of course, if I'd attempted to build a FOUR legged stand, NONE of 'em would have been even close.
The interesting thing about "Tubemiter" is that it uses the additional parameter (wall thickness) to generate TWO curved lines. The difference between these reminds me of the "wing tip" on "wing tip" shoes. Apparently it represents the material that has to be removed to get the joint to fit up.
In other words, if you were to taper the INSIDE of the pipe wall to fit the joint, the outer wall would represent the outer line in the template, and the inner wall would match the shape of the inner line.
I've had very little experience with either of these programs. But I think I like "Tubemiter" a tad better.
V
Reply to
Vernon
Just multiply by 25.4 and you have mm from inchs.
BTW, You can use a PDF print driver to capture the output.
Reply to
cl
Me too. Only wish it supported inches, and that you could export the image to something useful (JPG, ...?) and that it knew about pipe & tube sizes e.g. 2" Sch. 80 pipe. Heck, I might even be willing to pay a little for such a program.
GWE
Reply to
Grant Erwin
Ok - where did you find it ?
Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder
Vern> I have "Winmiter" and "Tubemiter". Both these are freeware.
Reply to
Martin H. Eastburn
Martin,
I don't remember where I found it. But it was on the internet. Search Google for "tubemiter". If you can't find it email me at vtuck at tucklings dot com and I'll see if I can find it again.
V
Reply to
Vernon
Great -
Found it ! and more naturally -
There is a text file lower down - might be useful.
formatting link
near the bottom of the page.
Tubemiter.exe by Giles Puckett (123k) tubemit3.txt by Pucket(2k) *.html format (4k)
The header of the page : [ forced wraping ]
Sanders, Snyder & Tetz
set of Useful bike specific TOOLS in spreadsheet format.
Webmater note: This is a very useful set of spreadsheets and represents many, many days of work by the authors.
We are supplying a set of spreadsheet tools that will give a user the ability to quantify bicycle related issues such as determining your own power capabilities, power vs speed, power to climb hills, CdA (aerodynamic drag), Crr (rolling resistance), and many more. We have set up separate spreadsheets to reduce informational overload, and a set of associated descriptive texts. We also have included instructional texts to help guide the user in making proper measurements.
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder
Vern> Martin,
Reply to
Martin H. Eastburn

Site Timeline

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.