Bending a stuffing box tube

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Hi. I am new to RC boats and can't find any info on getting stuffing box tubes bent to a required profile. I saw a video showing that a flex shaft works best in a gentle "S" bend rather than a single curve. Yes ... No ... ??
I am building a 48" V bottom "Fountain" hull with a Castle 2028 motor. Just starting the research.
Thx

[fweasel]

I anneal the brass tube by heating it with a propane torch in the area I need to bend just until I can barely see the color change, you do not need it cherry red, then cool immediately with cold water. The tube will bend quite easily by hand after this process. I then heat the tube again and let i air cool. You'll be fine with just a gradual single curve bend. With more aggressive shapes, some recommend filling the tube with sand before you bend it to prevent kinking.

[Old School]

Firstly, I cut a profile in timber thicker than the diameter of the tube. I then attach the profiled piece to a block of wood and clamp in a vice (vyce for those north of the equator). A piece of dowel is inserted in each end of the open tube to hold while heating the tube. I use a gas torch designed for chefs to make creme broulle, etc, to heat the tube. When the colour has changed, holding the dowels at either end of the tube I bend it around the formed profile.

To maintain the original hardness of the tube then immediately quench in cold water. If you allow to air cool then the brass remains in its soft annealed state of hardness.

[fweasel]

...

[TRUCKPULL]

Sorry guys - Brass

Heat - then quench in water makes it soft for bending.

Heat - then air cool makes it hard again.

https://www.offshoreelectrics.com/bend-brass-tubing.php


Larry

[Stillwet]

https://www.micromark.com/5-piece-Spring-Type-Tube-Bender-Set

https://www.harborfreight.com/tubing-bender-3755.html
these are just references since they have many different sizes. i have them as small as 3/32" through 1"

[NativePaul]

I find that the thin walled brass tube found on K&S or Albion Alloys racks in model shops is easy enough to bend over my thumbs without annealing it or using tools.

But if you do want to anneal it Larry has the right method, it works the other way round to steel, which is the process Old School is describing.

[Prodrvr]

Spring type tube bender...best tools I ever bought. No annealing necessary with brass tube. I use seamless stainless steel tube for my flex shafts.

[royalcasa]

This was my first time bending stuffing tubes, Twin Cheetah. I bought pipe bender and spring tube bending, I didn’t get the results that I was looking for with this items. I am sure I was the problem, what I did have success with is my hands and fingers . I started by cutting a 10” length tube then filled it with sand and bending it with my hands and thumbs, I got great results. I took me three attempts to get the bends I needed.

[[email protected]]

Thanks to all. Now to practice with a scrap piece.

[Shooter]

Make sure you put a line on it with a marker/ruler. That way you know you are bending in the same plane every time while adjusting it...or bend it while against a flat surface. It's an iterative process of gradual bends and checking......until it's perfectly aligned. I usually put the flexshaft in the tube and the collet on the motor shaft without the set screw. It should spin freely on the shaft without binding if your alignment is correct.