BigPoser

Hey All,

Wondering which size hole saws I need for mitering 28.6, 31.7, 36, and for a BSA bottom bracket.

Also, is there a decently priced mitering jig that you can recommend?

Thanks.

Brandon

Andrew R Stewart 

1 1/8", 1 1/4", 1 3/8" for the tubes and 1.5" for the shell. As common a bit of filing touch up is likely. Any one hole saw will cut a bit to more then you want oversized frequently. You can reduce this by careful grinding away of the teeth outer surfaces, selective grinding helps to correct for out of round. Purposeful out of round can increase the miter diameter a tad.


As to a miter jig- I made my own based on Alex Meade's tube blocks and some extruded AL. Andy

dsaul

All of the hole saws, that I own, have the metric equivalent marked on them. 1 1/2"(38mm) works well for bottom brackets.

If you have a mill with a vise, no special jig is required. Paragon tube blocks and a digital angle gauge work very well. If you don't have a mill, JD2 makes some nice looking notchers. https://www.jd2.com/p-63-notchmaster.aspx

prototoast

I use the JD2 Notchmaster + Swag Offroad Reach Around (JD2 Notch Master Reach Around) + a digital angle gauge.

unterhausen

I need to try my lathe-based setup again now that I fixed the massive slop in my lathe cross slide

BigPoser

Thank you gentlemen! Yeah I don't have a mill at the moment, but that may be something that will come in time so for now a jig will have to work. I had thought of the cheap HF version just to get something and play with it a bit, however, I don't really know if that money would be well spent opposed to just putting it toward something nicer right from the start. This is something that will be more than a hobby and I don't want to re-buy a tool down the road.

So it's safe to assume that I need to look at the OD of the tubing and match that with the corresponding hole saw. Easy enough and what I thought.

Thanks!

Brandon

BigPoser

What this work well?

Eastwood Professional Tubing Notcher

Andrew R Stewart 

Sure, maybe, depends. Many of these notchers have their slop, offness and drift of the intended angle and centerline. Of course nothing that a well drawn file won't correct if the length fudge was big enough. Andy

BigPoser

Pretty much what I was thinking. I don't have a mill so I'm thinking I'll have to deal with a little bit of slop and drift from just about anything. Certainly don't want to go with the Harbor Freight option.

Thanks Andrew.

unterhausen

it's really not that hard or slow to miter by hand.

JohnDThompson 

Indeed. Unless you already own the machinery, it's not really worth it to mechanize the process if you're just doing a one-off frame or even a handful of frames a year. I use a nice investment cast lug or bottom bracket to scribe a mark on the tube and cut and file to meet the scribed line. Otherwise, there's software that can print a template onto paper, you trim the paper and tape it around the tube and cut and file to meet the paper:

MozBike.com: Giles' programs

Andrew R Stewart 

For a few decades I made my average of 1.1 frames a year using a bench grinder and files to miter with. I already had the Vernier Protractor but could also have used a hand drawn angle template. I tried various ways to power miter over the years. My 6" Atlas lather is too sloppy and too small to do well. The two Joint Jiggers I have used both cut the angle off a few degrees, needed to be aligned/shimmed to have the miter be on center and were as loose as the lathe was so had to cut really slowly. It was Doug Fattic's Bridgestone mill that convinced me I needed to up the anti so got a used mill. Now it doesn't take too much different an amount of time to do a miter but the process is far nicer to do. Andy

unterhausen

I use paper templates. Don't judge me bro

Someone recommended bahco files. Unless you live somewhere with better hardware stores than I do, you are going to have to mail order them. I would get 8, 10, 12, and 14" half round files and use the one closest to the diameter of the tube you are fitting.

Cynikal 

There is no better tool for paper templates than this. TubeNotcher Pattern Creator Tool

unterhausen

bikecad pro has a template tool, but I think there may be some relation to that one. Just make sure you print full size, otherwise it won't work right.

David Tollefson

The Nova site has a notcher/miter facility also: Miter Your Tubes with Tube Notcher ! :: Nova Cycles Supply Inc.

WheelNut2

Do not buy the harbor Freight tube notcher. I bought one last year and it is completely and utterly useless on bicycle tubing. Files and a paper template are much better.

fietsbob

Yes, half round files , are good..

Le Mechanic

It really depends on your budget. In a perfect world, a mill is the way to go. The paper template and cutting/filing work well, are cheap and relatively easy to do. I actually bought one of the Harbor Freight tube notchers and have gotten pretty decent results from it. I'm not gonna lie, it does require some "tinkering" to get it to work right, but I've found, for me, it works much quicker than the paper template method with the same results.

WheelNut2

What sort of tinkering was necessary?

Andrew R Stewart 

I don't know about WN2's tinkering but I found the jiggers I tried were off center and the angle would drift a couple degrees. I would run the miter a tad long and file back to center and on degree. On the first tube miter this is easy peasy. On the second it's as long as just filing by hand IME.


I was able to center one jigger I had for a while and began to learn to over set the angle to get close. Still I felt the need to follow up with a file every time more then I would have hoped going into it. Andy

Le Mechanic

Basically, the fixture that holds the tube was about 2mm too far in from the center of the hole saw. I just spaced it to the correct plane with some chainring spacer washers. Although not necessary, I also welded a plate to the bottom and got rid of the original mounting plate. That just made it easier to mount to my drill press, as well as increased the overall rigidity of the unit.
I made a youtube video a year or so ago about what I did and how it was holding up.