the hand mitering thread

[dbohemian]

Thanks Dave. Do you scribe a line directly with the jaws of the caliper, or do you use an actual scriber? I know it's not proper practice to use caliper jaws as scribers, but with cheapo calipers I do it anyway. I'm wondering if those squared off jaws actually let you make a scribe line in the layout fluid?

Alistair.

Once the first miter is created (lets say the DT/HT) I move the block to the very edge of the bottom side of the miter which is where the measurement from the computer is located. I use the other block which has not moved to re-key this second one while on the surface plate. I then set the caliper. Hold the tube in the vise because the caliper is heavy. Put the fixed jaw against the side of the block, rest the caliper on the back half of the vise and at this point with one hand you can use a sharp scribe to mark the other end from the movable jaw along the tube which should show nicely with some layout fluid or sharpie.

The jaws are square edges which does not really allow you to use the jaw tips for marking.

[Alistair]

Crystal clear Dave. Thanks for the detailed explanation.

Alistair.

[einreb]

For hobby folks only: Since it may be weeks (months?) between mitering tubing... I always make it a point to start with the BB shell lug miter on the seat tube since the tolerances aren't as big a deal and it allows me to get my mind in the right place... working my way around to the dt and then the tt being done last since the length and phase is more critical.

-Bernie

[Stijl Cycles]

How do you do this?

It's totally convoluted, but it works:
In the export miter dialogue I choose 0.0mm wall thickness (just to keep the miters clean of lots of lines I don't need)
I bring the PDF miter's template into Illustrator, select and copy to the clip board the top tube and down tube miters and past them into a separate file, or at least get all the miters desired into one file.
Export them as a DXF, open them in AutoCAD or Rhino (this works the best).
Decide what line is going to be my common (top of tube or bottom of tube), make two copies of the miter that needs altering, cut the bottom off of one, the top off the other and then assembly the two halves to match the common line chosen. I get rid of the all the other lines and text, just leaving the outline of the miter I want (including getting rid of the extra lines on top of lines).
I export it out (this is where Rhino shines) into a format that I can bring back into the vinyl cutter.
A point of note, be sure to keep the units and the scale the same each time you export and import between programs. If you export the file out as Picas and import in as Inches = no good.
If you do not have access to such programs... join me in my one man revolution to get Brent to change the way the Miters are exported.
export the

[shand]

If you already have the files in Illustrator why not just do the editing work there? I'm not sure I understand why you need to pull it into a CAD application??

[prolix21]

I've only got one frame under my belt, but having mitered with a mill and by hand I definitely prefer by hand. When I was on the mill I felt like I had lost a lot of control and I was moments away from a disaster. 50% of that was probably my inexperience with a mill, but there's a lot to be said for taking machinery out of the equation. Seems like you can ease into the miter a bit more slowly and catch errors more easily (without trashing a tube)

[pruckelshaus]

For hobby folks only: Since it may be weeks (months?) between mitering tubing... I always make it a point to start with the BB shell lug miter on the seat tube since the tolerances aren't as big a deal and it allows me to get my mind in the right place... working my way around to the dt and then the tt being done last since the length and phase is more critical.

-Bernie

I do exactly the same thing.

[adarn]

Since no one else has said it...

I print and cut out templates fron Nova's site, tape them on the tubes in the right place with scotch tape, then I hack saw some "V"s in there and finish it off with a file.

Sure I slip and mess it up sometimes, but another piece of scotch tape fixes that right up.

[Stijl Cycles]

If you already have the files in Illustrator why not just do the editing work there? I'm not sure I understand why you need to pull it into a CAD application??

Competency...

I am really not that skilled with AI, but have 15 years of CAD and Solid Modeling under my belt- Use the tools you know well and get the job done. If you have time to learn something along the way, apply it as you can.
I have a friend that does all his drafting in MS Word. I have no idea how he does it, but he is really good at it.

[shirk]

Okay so I've just re-read everything here and have a question.

Does anyone have any tricks to keeping hand miters in phase when not using the fixed tube blocks that Dave mentions in his post.

I started my first miters with the printouts from Nova, but I've tossed them. Last night I had to ovalize the 38mm DT to mate up to a 36mm HT so it was time to jump into the deep end and just rely on the bevel protractor/file/eye and work it to fit.

I think I need a set of v-blocks, I have a reasonable piece of marble counter top that is fine for my surface plate. This way I can at least hold things steady on my flat surface to see if stuff is in or out of phase.

[e-RICHIE]

I hand miter in phase by hand, and always have atmo. When I am showing the second cut who's boss, it is facing up vertically in my vice. The first cut is at the bottom, and positioned using an off-cut of the pipe t mates to. I rotate the pipe in the wood block so that the lower miter is facing straight ahead. Then, using my stance, body English, and muscle memory, I whale on the second cut in the same direction as what I've sited down below.

[Mark Walberg]

I hand miter in phase by hand, and always have atmo. When I am showing the second cut who's boss, it is facing up vertically in my vice. The first cut is at the bottom, and positioned using an off-cut of the pipe t mates to. I rotate the pipe in the wood block so that the lower miter is facing straight ahead. Then, using my stance, body English, and muscle memory, I whale on the second cut in the same direction as what I've sited down below.

This is what I do, too. Not that Richard needs an endorsement from me. I mitered a top tube this way last weekend. It is easy getting the miters in phase this way. The eye is pretty good at this. No extra tools needed, just a file and the tubes.

[e-RICHIE]

I gotta add this (mostly because the questions come from noobs and hobbyists...) atmo - you have to learn with no tools, or a minimum of tools, before you can even begin to notice what's happening when you add precision or measuring devices to the equation. You want these tasks to become intuitive, trust me on that. Mitering a tube by hand, one side or both, can be a three minute ordeal if you think it through.

[shirk]

Sounds good. Eye baller it and show it who's boss.

That is how I did the first one, just wasn't sure if I was yet to learn some other jedi trick of the masters.

I posted a pic on facebook last night of ovalizing a tube and then front triangle layout on my drafting table and a friend asked me today about if I had any special cutting jig for the miters. Nope just a hacksaw and hand files per instructions from the masters. Get-r-done with next none.

[WadePatton]

In the spirit of hand-mitres/copes/fishgapes in these days of ultra-precision computer design and modeling,

a few mm's here and there in "fitted" tube dimensions won't "blow" your careful design work.

Stated otherwisely, be a slave to good joinery, not a calculated tube length.

Eye Baller it and show it who's Boss.

touché

[Andrew R Stewart]

My teachers would have me do the first miter then cut and begin the other (second) miter with eyeballing it but allowing a couple of MM's extra tube length. Then by holding pieces of tube at each end and seeing how the miters' alignment was fine adjusting the second miter to bring the two into phase.

Scribing a center line along the tube's length can help minimize the amount of off phase of the rough cut/miter. Andy.

[Jake Rosenfeld]

.

Scribing a center line along the tube's length can help minimize the amount of off phase of the rough cut/miter. Andy.

And this can be done easily by holding two tubes together on a table and wiping a sharpie down the crack

[bencooper]

I got some U-section aluminium, and attached a ruler to it - great for measuring tubes and drawing straight lines on them, that's how I line up mitres.

[suzyj]

I got some U-section aluminium, and attached a ruler to it - great for measuring tubes and drawing straight lines on them, that's how I line up mitres.

10mm aluminium angle section from the hardware store. Cheap as chips and plenty accurate. Draw a line down the tube and use that to line up your mitres and bang your bidon boss holes into.

[Will Neide]

10mm aluminium angle section from the hardware store. Cheap as chips and plenty accurate. Draw a line down the tube and use that to line up your mitres and bang your bidon boss holes into.

This is what I do as well.

All my tubes get marked with centerlines this way. I'll occasionally mark the top tube with a center line on each side of the tube. Make your centerline with a the aluminum straight edge, then put my tubing blocks on the tube so the seam lines up with the center line and then mark the opposite seam (180 degree mark) and make another straight line with the aluminum angle. I always mark my lines "top" and "bottom" if making two lines. Before I cut my tubes, the center lines are marked, butt lines are marked, and sometimes small notes reminding myself which end is "head tube" or "seat tube" end.

I usually use cutoff wheels, grinders, and templates. Pretty quick, accurate, and painless. I have a tube notcher as well, but have been using it less and less since cutoff wheels and grinders works so quickly.