[Joel] is setting up a really nice workshop. Included in his list of machinery are the staples of any workshop; a lathe, miter saw, containers full of organized screws, and a manual mill converted to a CNC machine. [Joel] wanted an oiling system for his mill, and like any good maker decided to fabricate his own. This required bending very small diameter brass tubes, something doable by hand (or without sand, at least). He decided to solve this problem with a DIY tube bending tool that allows him to bend tiny brass tubing without the walls collapsing.
[Joel] broke out his lathe and machined two brass rollers with a groove to hold his 3/16″ tubing. One of these brass rollers is attached to a handle, while the other is attached to a block that gets clamped into [Joel]’s bench vise. After threading some tubing through the rollers, [Joel] is able to bend it precisely with only a tiny bit of collapsing on small-radius bends.
Hmmm… I’d like to see the details, but either the link is wrong, or the sites been Hackaday’d
Yeah, can’t access it either.
It’s up, but slow. Keep hitting F5. That’ll make things better.
LOL… should be better now
A much simpler way is to fill the tube with a frozen mixture of detergent and water prior to bending, similar to how they make bends in brass instruments. It’s pretty much the exact same material too, thin-walled, small-diameter brass tubing.
I was going to suggest the same thing. I just watched an episode of “How It’s Made” where they used that technique to bend trumpet and trombone bodies.
For anyone interested…
http://www.youtube.com/watch?v=8NAaRQUTp9g#t=197
Sorry, I had linked to 3:17 ( ish ) where they actually start filling the tube, freezing and bending.
Thanks!
If you think filling and bending is simpler then you have not tried a real tube bender, it literally takes seconds to do perfect and accurate bends
http://www.youtube.com/watch?v=W6usvOZ9yIw
something like a trumpet is different the walls are too thin compared to the OD to just bend
I still appreciate these simple purposed hacks.
Too bad we don’t have a bending unit…
or fill it with sand before bending…
An old-timer trick for small-diameter tubing is to use salt, as it can be dissolved out with water..
I’ve never worked brass. Can you heat the metal to make it bend easier?
I have a couple of commercial small diameter tubing benders. They’re handy when I have to make custom brake lines.
raer has the right idea. Filling it with sand is the common technique for bending microwave waveguides, where you REALLY need to minimize cross-sectional changes.
And for the diameter in question, pcf11 is right. 3/16 is common enough for a brake tubing bender.
Don’t get me wrong, this is an awesome hack. And I love the job Joel did. But it can be done off the shelf for about $10-$20, with a lot less hassle.
Unless you’re working with rediculously thick walled tubing, nylon rollers are perfectly adequate for this sort of thing. Also, 3/16 is a standard brake line size, so there’s no shortage of affordable commercially available solutions to chose from.
Step 1: Spend $2,000 on a lathe. LOL
I was thinking a constant air pressure inside might help to keep it from collapsing.
Nope.
You need something that won’t compress or flow. Otherwise the pressure at the bend will just redistribute to the rest of the tube, doing approximately nothing.
Simple enough. The spring based ones work well too as well as filling the tube with salt.
On the oiler side the guy really should be using Bijur metering units to send the oil to the ways. It will get even flow to all the ways. They are pretty cheap, the restrictors are cheapest from the Monarch Lathe service department and you can buy tees and manifolds off ebay all day.
Interesting, I’ll look into those. I intend to use my custom-made fittings (http://jmillerid.com/wordpress/2012/06/cnc-mill-oiling-system-concepts/) to adjust the flow at each node, but I can imagine it will be a time-consuming process.
…”something doable by hand (or without sand, at least)”.
Was this maybe supposed to be ‘something NOT doable by hand (NOT without sand, at least)’?
Personally I think the statement in general feels clumsy and could likely use an all-around revision…
doesn’t bending pipe with these type of tools weaken the metal in the bends? I seem to remember reading that if you’re going to use any metal in structural applications you should use heat bending methods.
It will weaken the material slightly, but I’ve never seen brass tube of this size used in a structural application. Bending metals with heat although easier, can weaken the material much more if the right heating and cooling processes aren’t used. Some alloys require multiple heating and slow cooling to restore original grain structure.
I use 1/4″” / 3mm copper and brass to make flash steam boilers for toy boats. I have always found that annealing the copper does the job. Heat the pipe to dark red in a flame (a gas cooker works OK) and then quench in cold water. The tube will then bend easily around wooden dowels and blocks. It will work harden so for compound bends you might need to re-anneal. The pipe does flatten a small bit but nothing to slow the flow.
If it’s not powered by a 6502, then it can’t be as good as the real Bender.
We actually supply these brass and copper tubing for hobbies, call us up for any questions regarding sizes and shipping for any hobby jobs.
I would suggest blanking 1 end with duct tape and pour water in the tube and blank again the other end. Put it in freezer
,when fully frozen you start bending it. Others are pouring molten lead prior for bending and later on removed the lead by heating.
Thanks for your advice here! If you’ve ever had a broom handle made from light metal tubing, chances are you’ve had it bend. That’s why I looked into this, when you try to straighten out the broom handle, it is structurally damaged and cannot be repaired. I imagine the problem is similar with larger tubing as well. It’s good to see how the professionals do it.