Want to share a good idea on bending stuffing tube

[Kez]

I was watching How it is made the episode of how they made a trombone. To make those 180 degrees bends on the brass tubes, they first bend the tube on a bender. Inevitably, the process resulted in a slight kink. To take kink out, they inserted steel bearing balls the size of the ID of the tube and push them through the bend.

No mater how carefully I bend the stuffing tube, the brass tube will collasp slightly at the bend. I tried the same approach and used some steel balls 5.5mm in diameter and push them through the curve. It worked very well. 5.5mm balls is the right diameter for 1/4" brass tube. If you want to give this a try, make sure you put some grease in the tube. I used an old cable to push the balls through.

kez

 

[DON MAHER]

Great Idea, and will work to repair a tube that has been damaged.

Thanks Kez

Don

 

[Mike Hughes]

Another trick to put in my bag.

Thanks

Mike

 

[Tim_Duggan]

THat is a good idea - thanks for sharing!

 

[RaceCraftBearings]

Well your making a stuffing tube for the shaft you are going to install into it so the shaft you have on hand makes the perfect filler to use.

I even have a small flex cable I use to bend Fuel Tank brass. Been doing it with flexshaft for many years.

 

[camaroboy383]

its a great idea...now you get some drilled steel balls and run a small cable through it...run the cable through first then pull the bearing through....if you have a bunch of bearings line the cable with them and leave them inside while bending the tube using the balls on the cable as a mandrel...but the single ball on the end of a cable and drag it through would work fine...its obviously easier to do anything to brass tube if you anneal it first...

alden

 

[Tony Jacuzzi]

great idea where can you get steel ball bearings for the 3/16 and 1/4 inch shafts ?

 

[Paul Traufler]

Put tape over one end of the tubing, fill with plain old sand (or table salt) and bend like you would normal. The sand or salt will force the tubing to round bend not link.

 

[moparbarn]

good idea. i used to race vw's off road. we did the same thing to the intake manifolds, to eliminate kinks & flat spots. we called it ball honing. a spring bender that fits over the outside tube will eliminate kinks, also. many ways to skin a cat, great info.

 

[Jerry Wyss]

good idea. i used to race vw's off road. we did the same thing to the intake manifolds, to eliminate kinks & flat spots. we called it ball honing. a spring bender that fits over the outside tube will eliminate kinks, also. many ways to skin a cat, great info.

OR A DOG!

 

[camaroboy383]

tony you can get them at mcmastercarr.com in perdy much any material you wish...

alden

 

[Kez]

The way it works is to use many steel balls (not just one). Use enough steel balls to fill the curve section. You can then tap the balls through the bend from the straight section. Once the balls pass through the bend, the tube will have the same uniform ID throughout.

Alden, I am not sure if pulling a single ball through with a cable will work as the cable may bind.

I have not found the spring type bender to be useful particularly if you use the spring on the outside. I have tried inserting the spring inside the tube. It worked OK for a gentle curve but will still kink if the bend radius is small (like that of a 180 degrees header).

Tony, I used eight 5.5mm balls for the 1/4" tube. I removed those from an old bearing. I am sure you can find the correct size for the 1/4" cable from McMaster as Alden suggested.

kez

 

[camaroboy383]

kez,,,the cable im talkin about is like control link cable...if you have a kink that that wont go through,,,id suggest starting over....if you anneal the brass,, kinks will come way less....

mcmaster has any size ball u want,,,metric,,imperial,,hollow,,solid,,anything you want...

the 5.5mm steel balls come in a package of 50 for under $10.00....

 

[Nigtmare]

great idea where can you get steel ball bearings for the 3/16 and 1/4 inch shafts ?

Tony Canadian bearings have them.

Nick

p/s you may have too buy a bag of 25 tho :blink:

London

Canadian Bearings Ltd.

115 Midpark Rd.

London, ON

N6N 1B2

(519) 686-7600

 

[SeanKewley]

I anneal the tube first and then I cap one end and pour water in and freeze it. Once frozen bend away.

 

[moparbarn]

good idea. i used to race vw's off road. we did the same thing to the intake manifolds, to eliminate kinks & flat spots. we called it ball honing. a spring bender that fits over the outside tube will eliminate kinks, also. many ways to skin a cat, great info.

OR A DOG!

hush, you OLD DOG :lol: :lol: !!

 

[John Seybold]

Thanks for all the tips!