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Hi Todd,Quote:
Originally Posted by ToddFarr
Just free handing it. The photo is deceiving in that my hands are generally closer to the wheel when not taking a photo, etc. The wheel cuts through the thin wall tubing easily and so there isn't much back pressure. I work mostly with stainless tubes and there's a little more pressure with that, but still not bad, especially since mitering 953 tubes with only a file is a no go from my perspective.
Dave
I don't have a dog in this fight, but is there not a third path?
Attachment 50043
Commonly used by the people who build stainless exhaust systems. Adjustable for tube diameter and angle.
I have one of those. I got it directly from the Chinese maker about 15 years ago while living in Hong Kong. It is basically useless for frame building. Nothing but the BB shell will fit in it.Quote:
Originally Posted by illcomm33
What it works well for is small precision parts. You need to calibrate the bed if you work piece catches while turning otherwise you get runout. It will also cut threads pretty well if you have the gear set.
In Europe it is impossible to get tooth belts because the stock belts have an odd pitch. I made new tooth wheels so metric standard drive belts will fit.
This one seems to not have a motor speed control. My version has an electronic speed control.
Here's me milling square holes:
http://farm2.staticflickr.com/1204/6...46ba8629_z.jpg
I have one of those, but I haven't used it for frame tubing yet. I worry the v clamp will dent the thin wall tubing. I thought of making a hardwood or aluminum inset to prevent this but I have been working on much more important things (non functioning heating system in my home) rather than making bicycles.Quote:
Originally Posted by Mark Kelly
Got a link for where to purchase said item?Quote:
Originally Posted by Mark Kelly
https://jointjigger.websitesource.ne...x.php?cPath=21
I have the purple one.
I've tried a few mitering processes over the years and come back to hand jobs each time. The light weight bench top lathe with the milling vice (Atlas 6") worked about as well as the Joing Jigger did. Both had a lot of slop, didn't hold the tube securely and the resulting angle that was cut drifted from the intended. Both were tried with added tube clamping with not better results. With the common hole saws' tooth count (6-10 TPI) the teeth can snag and catch on the thin wall tube. I had best results with running the hole saw at a significantly higher speed, still the miter was not fit up ready. For a roughing out these methods are fine enough but, and I'm not very fast, I can rough out a miter in a few minutes with a hack saw and a bench grinder. I would not reccomend a Joint Jigger without reservations. Andy.
My experiences with them were less than stellar as well. For a long time I hand mitered. I even have a few frames up in the rafters that I cannot believe I actually hand mitered (full aero time trial stuff). I tried the jig a notcher, the drill press, a bridgport that I had set up for everything and it did nothing well. I even made a abrasive mitering tool that actually worked pretty well on main triangle tubing but not seat stays and the like (that is something I still want to re-design someday).Quote:
Originally Posted by Andrew R Stewart
For me, if one is going to make the leap into machine mitering it has to be all or nothing in order to give the speed, accuracy and repeatability necessary to make financial and time saving sense. Now I have a dedicated Hardinge horizontal mill that is never used for anything other than main tube mitering along with an older style Anvil fixture and it really works wonderfully. I am in the process of setting up a Nichols mill to do this same thing and the Hardinge will be for seat/chainstays. Just an offhand note, sometimes you can find a mill for a fabulous price. They are out there. My Nichols is in really great shape and I paid 300 dollars for it, although that is probably the best deal I ever got on something it still goes to show they are available.
This subject thread has taken some interesting turns and I'd like to be one that encourages rather than discourages - for the young and impressionable new builder seeking advice - learning how to use mills and lathes. It is a great way to help understand how metal parts are made and go together. One of the first things I did when I got back from my apprenticeship in England was to take some machine shop courses. I would never ever want to undo that learning. It is a skill set that makes me a more complete builder. Certainly these tools aren't the first things a builder should get (although a case could be made that it is better to start out making fixtures than buying ones) but having and using them are an advantage. The kind of steel custom bike most likely to be made in today's market is some kind of utilitarian bicycle with many accessories. Making stems, racks and kickstand plates are part of the skill set one needs to have when building something besides a racing style of bike (and to compete with other builders making similar utilitarian bicycles). Using only a hacksaw and hand drill isn't the most efficient or effective way to get some jobs done.
I've had a number of people apprentice with me over the years. One of the first things I do to establish foundation knowledge is to teach them how to use a Bridgeport mill and South Bend lathe. It isn't just learning how to calculate cutter surface speed for a particular metal, its about problem solving. It is the ability to figure out the sequence to do something in a logical way. This kind of training is how to think to see the big overall picture so one can be a manager knowing how things should be done and not just be the grunt on the floor doing the same thing over and over again. In other words learning how to use machine tools teaches one how to think logically. We can all use more of that.
I'm not saying hand mitering doesn't make sense for some people, is just shouldn't be seen as an advantage for everyone. It isn't a superior way, it is just another way if one eventually gets good at it. There are advantages to using my Bridgeport to miter tubes. For one thing I'm going to be spot on accurate in every detail, the miter is going to be in the center of the tube at the correct angle at the right diameter. The other end of the top tube is going to be exactly at the right length, in phase with the first miter as well as be in the center at the right angle with the right diameter of scollop. I like that. I can show a novice how to do it and in less than a half hour so they too can be getting perfect miters. Instead of doing 5000 practice miters to get it right (that is an exaggeration to make a point), they can be filing lugs or dropout connections or practice brazing to get the hang of how to use their hands. I might add not all machine mitering practices are the same. There are big variations and some can be faster and more accurate than others.
Separate from using heavy machines for bicycle mitering, I really want a milling machine and lathe for other purposes. Threading, splining, redrilling rotor bolt patterns etc would be the uses I would have for them. Also, when you consider things like carpal tunnel syndrome, which I have and already had two surgeries for, reducing the stress on the wrists is a good thing. If I had the machinery, I could weld the same day as I mitre, which I cannot do now as my hands are too shaky and numb after a day on the tools. Its a good thing I have no desire to build things for a living, but just as a hobby. Making my own tooling is something that really interests me as well.
This is a good point. Luckily it seems that many people can do repetitive, manual tasks for life and not have a single issue while others are greatly affected by use/overuse issues. Some things may be hard for a framebuilder to keep up for 20-30-40 years without pain. I know when I sand or polish a lot my hands are really sore and I have looked for ways to reduce the effort while keeping the quality up. Pain and preventing further injuries may be justification enough to use a tool to help.Quote:
Originally Posted by Willie1
Okay.
I too do not really have anything at stake in this thread, but , as experience has taught me this:
dont buy that desktop shit. it's shit. It just is. It seems it is only made to fail.
Like winter riding, there are really only two schools that work in the coping, mitering, notching world :
get a mill. A real mill. A Bridgeport or similar. Get the ANVIL set up. That is one hell of a way to cut tubes. This is one way of doing it, and it requires money and some machining experience. Those skills are always transferable down the line. This may be "cost prohibitive " to some, but, well it takes money to make it efficient. These can also help if you do develop pain in the hands, arthritis , what have you.
Method 2:
get some blocks, a vise and some files.I did this method for years.It works, and is building a skill set that is essential in frame building. It also comes in handy in other areas of life and work.
I do believe that everyone wanting to build frames should do this for a year. It's the "wax on wax off " frame builder skill building time.
Seriously, please don't buy stuff like that, it will only give you problems done the line, and , if you solely rely on machines to do your work, then your skills will ebb and fade.
Keep it real, and long live the file!!
Another eight and we'll have a minyan atmo.
AS long as the year means working daily towards an end...Quote:
Originally Posted by liberacefanboy
Yep. I dont send people out into the shop to JUST FILE. There has to be a goal to every exorcize, or, well its just not worth it. Giving someone a coupla tubes and a file is not enough anymore. Proper use of the file must first be taught, then when the understanding of USING the toll one can truly understand its use.Quote:
Originally Posted by e-RICHIE
Understanding the use brings you closer to the end. Thats how I see it.
Well Jack do you wanna learn to build a frame OR do you wanna learn how to build frames atmo?Quote:
Originally Posted by liberacefanboy
Richard Sachs: Sustaining As A Process | RICHARD SACHS CYCLES
I have to agree with the old skool here to some extent and this also goes to some degree in another direction altogether
GET READY FOR A RAMBLE
A cheap chinky chonk machine ? theres an entire team of hobbyists on the web who turn them into great little machines
Over here in the UK myford lathes were regarded as the defacto standard for hobbyist engineering types In er proper engineering these folks lust after harrison bridgeport colchester etc etc ,the demise of lots of these company's saw these things go up in price and "like any old iron is somewhat revered" theres still a snobbish attitude towards old machinery being better than the taiwanese shit.
Amazing things are still done on these knackered machines but recentley these old school engineering types who are for a lot of the part apprentice trained (journeyman types) and what you might consider have gained considerable industry experience are turning to china town machines
their myfords are knackered worn out ,kaput...restoration projects in the making but heres the thing even on an old worn out machine a skilled turner will produce an absolutely bang on piece of work
Now they turn to the unworn unspeakable dreaded chinese mini lathe ,however in the same way they can get an old worn out machine to produce the part they can do the bang tidy work also on these things too? WHAT GIVES its an argument thats been done over and over on the machinist forums
I read people worried about their accuracy of surface tables etc on here and if you ever get hold of a book called the foundations of accuracy its an interesting read ,and will put all your worries to bed in terms of how accurate things need to be, it wont make you a machinist but might make you think outside the norm
you can have a fancy tube laser worth half a million quid sat there ready to cut the tube in a little under 2 seconds if you get the skill and experience down you can mitre that tube before windows has had chance to start up to program the profile
my point Experience and practicality (as doug mentioned above) counts a whole load more than the tools in the box
Nice.Quote:
Originally Posted by Mike Mcdermid
All I really have to add is that as a finished product, a straight bicycle frame doesn't give a hoot about the path you took from A (raw tube) to B (mitered tube). As long as it's a clean miter and everything is in phase, the frame will be fine. You should play around with as many different ways to get from A to B as you can and figure out one that works well for you.
If you're interested in developing better file skills - the bikeCAD templates that dave anderson referenced are a really great way to get there. Likewise, you really don't need to buy a full size 2-tonne vertical mill to make a bicycle frame. A decent mill-drill with some tube blocks and a tilt-vise or rotary table will get you there just fine. I'm pretty sure many of the west coast mtb guys (and garro too) use this set up precisely because it's economical, effective, and doesn't require a large footprint in the shop. If you have the money, inclination, and garage/shop space for a huge machine then go for it; buy a nice one, it'll hold its value, you'll probably learn how to do a bunch of stuff on it that is way more useful than making bikes.
EDIT - actually, come to think of it I think garro/hunter/sadoff/etc use a shaft vise and rotary table combo.
Can a moderator erase the inherent racism here?Quote:
Originally Posted by Mike Mcdermid
Before this thread veers off topic....
Keep in mind that just getting a machine is only solving half the problem: you still need to hold the tube. This means you'll either need to buy some form of mitering system (very expensive, and too big for such a small lathe) or make something (still expensive, plus a bucketload of time)
When shopping for my lathe I kept hearing "you'll spend at least the same amount again on tooling" and it's totally true - make sure you factor this into your tool-buying.