Bending a short stuffing tube?

[kevinlew211]

just use a longer tube, bend it with your bare hand and cut out the 2" part you need

[ray schrauwen]

Knowing that I'll have maybe 2" of stuffing tube in my mono, while I'm waiting for parts I thought I'd practice bending the

After a few attempts, this is what seemed to work best:

• Cut a piece of brass tube about 4" long.
• Anneal the brass tube.
• Insert a K&S bending spring inside the tube.
• Insert the tube into the hole in the transom.
• Using the exposed part of the spring, I pulled up and the tube bent as I pulled up
• Remove the tube from the boat, remove the spring and dremel the tube to the right length.
• Deburred the tube and put it back into the transom hole.
• Line up the motor and tweaked the tube to align it perfect.

Does that sound about right or is there a simpler way?

Also, I see an advantage of not rehardening the brass tube so to make any final adjustments easier. If I plan on using a teflon liner, how important is it to reharden the brass tube.

Thanks in advance.

Those springs go on the inside??? No wonder they never worked for me...

[rickwess]

Those springs go on the inside??? No wonder they never worked for me...

I've was sacrificing some more brass tubing last night. There is a spring from that K&S kit the fits snugly into the 9/32" tube. I've found that I don't need to anneal the brass if I use the spring on the inside and use the tube bender tool to make the bend.

[srislash]

Well you got that licked, now for bending tube for in hull water pickups. ;-)

BTW- table salt or fine sand inside also can help.

[Tech Head]

I use a flex shaft inside the stuffing tube to make a bend. Just make sure it's a snug fit.

[Fella1340]

I found using a regular tube Bender, simular to one for brake lines that the tube would distort. More when I did it by hand. I liked the idea of softening the tube and maintaining the outside tube diameter when I do a bend. This is just what worked for me, the tubing was quite old so it may have work hardened somewhat over the years. I will have to get something that is meant to work with brass tubing, any ideas on what works best?

[Southwest]

Fella- I agree what you typed. I soften with a drill bit in brass and heat up and gently bend and keep diameter all the way thru bend with ease and no kinks and let cool . Now if you use liner, the liner will find the kinks when inserting it.

[785boats]

I'm with RaceMechaniX & Tech Head on this.
I've never heated brass tubing to bend it. Just insert a bit of flex shaft of the right size, with a bit of liner if required, & bend it with your fingers & thumbs. Gently. Then cut off the excess to suit.
I've even used some of that Plastruct or Evergreen styrene rod. Just find the tightest fitting rod for your size tube at your local hobby shop.

https://www.google.com.au/search?q=plastruct+rod&espv=210&es_sm=93&source=lnms&tbm=isch&sa=X&ei=31SrUo54ipmJB-WogKgJ&ved=0CAkQ_AUoAQ&biw=1726&bih=930#es_sm=93&espv=210&q=Evergreen+styrene+rod&tbm=isch&facrc=_&imgdii=_&imgrc=cHOxjD8VMFTPvM%3A%3BsqPOVWnRjbCZlM%3Bhttp%253A%252F%252Fdollkm.info%252Fgadgets%252Fimgland.php%253Ffl%253Dg4r4q4m4b4q254q464v214h414x4v5w5g5p4k4n2g5j4r5o2n4j474c4e4z4i4o5b4x526r4k5y524z3d4l4a4l4v5n306m4j5u434o4d3k4h5p5k5l4o264z5b444q2u204x2u2o263r23413z3r5p4m5%3Bhttp%253A%252F%252Fdollkm.info%252Fevergreen-scale-models-213-styrene-rod-100dia-5-trains-ho-modern-miscellaneous.aspx%3B500%3B231

[tlandauer]

I feel strongly about not annealing the brass tube. I have been using the flex cable with liner and the bending is a no brainer. The trick is to have a snug fit. That is why the .187 cable with a liner that is meant for a .150 works the best for a 1/4" tube. I use my hand like above mentioned.

[Fella1340]

Rick, one of your posts mentioned not rehardning the brass after you complete, with or without a liner is just fine. I think the worst thing you could do is reharding with a torch and toss it in the water. Its likely to end up brittle from quenching. I work with lot of tool steels, most ends up heat treated and stress relieved. While brass is easier to work around and is quite forgiving for just about all our uses in rc. The brass would have to be heated at a for a set time and temperature, might involve a specified cool down time as well. Now we have all the brass uniformly softened. Then you can start the heatreating process to bring the brass back to its original state. I couldnt be bothered to get out a big book with all the big words in it. One thing I am positive on (almost:) that older brass Ooo seems to.work harden over time making bending without deforming the tube very hard. Just rattling in toolbox when the car starts, lawnmover and of coarse the vibrations that surround us really.seems to.do a number on it. I have been buying from a hobbystore that was established in the 1940's. The brass tubing is ancient as well. I am going to find a new source and save myself some trouble. So does anybody think not performing the heating amd quenching after softening is a horrific idea and a recepe for disaster? I hope most people dont care, what has worked for 15 years obviously works" I was told today at the hobbyshop. I found it interesting being new to.rc boats and a valid concern if you have no experience. Any.way you.do it shouldnt have an adverse effect. overheating tube could work out real bad. Likely on the wallet! So that was way to long. It almost put me to sleep. Sorry about that. Maybe somebody will chime in and wake us up and tell us how it must be.done! (wouldnt mind hearing correct heat treating for.brass. Perhaps it is as friendly.as O1 tool steel. You can make a great knife from it, harden and oil quench the blade. I like using heat markers for temperature though the masters that have been doing it all there lives go by colour and the work is razor sharp. Gotta stop, way off topic and nobody cares. I should have just said"run your flex in a softened tube because I like metal and alloys and been done with it.
Jeff

[rickwess]

Thanks guys. This has been a great discussion. See post #18 were using the spring and a tube bender, I can bend the tube as needed.

My challenge was the short tube and the desire to use a 1/4" reduction at the end of the 9/32" tube so the tube will fit inside the stinger mounting base. I found a tube that was pre-reduced (if that is a word) so I couldn't do the bend in the middle of the piece and then cut out what I needed. I needed to start bending at the reduce end, really 1/2" from the reduced end.