Dartman1074

This is my first time of installing a stuffing tube, It maybe an easy task for most but I am a little worried. Is there and easy way of installing it how about bending it? I have a tubing bender is that needed? I found one crackerbox someone did on here and I seen a few pictures but It doesnt look all that easy.. I have the zippkits I box. Thank you for any help.

martno1fan

Hi mate all you need to do is work out where it needs bending then install the flex into the tube and bend it over your knee nice and slow so as not to kink it.Having the flex inside will stop the tubing colapsing ,works for me just take your time.Two ways to have the bend one is a gradual single bend or a slight s curve which is suposed to be a little more efficient ,ive used both methods and both work well.Heres a pic of an s bend on a hydro but same principles apply,just make sure when you install the tube you cut a slot in the transom to allow up and down adjustments and use silicone to seal it up,the other end is held via a tube holder,t bar or home made it doesn matter.
Mart

Dartman1074

Thank you, I tried to do it and got a kink in it so I am going to order a new one and try the way you have said to do with the flex inside.. Thank you again..

martno1fan

Use k&s tubing its the right wall thickness so its easy to bend ,sory i didnt reply quick enough to save you kinking that tube .

noisy

hi...if its a brass tube .. where i want the bend heat the tube then put into cold water this will make the tube pliable and it will bend easy...i just heat with my gas torch....bob

Dartman1074

Where can I get the k&s Tubing from? the one I had the wall seemed kinda thin and there was a linner inside also. Thanx again for your help

BMAD01

Dman, I see you are going to need a subsurface drive on the Ibox. With the stuffing tube thru the hull, in fact anywhere - I like to have the stuffing tube easily replaceable. To do this you need a short piece of 11/32" OD tubing (3 or 4") to run thru the hull. Your 5/16" OD stuffing tube will slide thru that making the tube replaceable in case it ever needs to be replaced. Here are a few pics of how I did it on my Stryker. Your boat won't be that much different. The tube thru the hull will allow you to bend the stuffing tube a little bit at a time until you get the perfect fit. I bend my tubes with the flex inside a bit at a time by hand, checking the bend and fit frequently. Have to do another post with more pics. Brian

BMAD01

The rest... Your boat is wood. You can build a frame out of 1/4" square and build a box around the 11/32" tube, then fill it with epoxy to hold it in. Just rough up the tube so's the epoc can grab onto the tube. Good luck, Brian

Paul M

Great job on the instructions, Brian. Where were you when I was doing MY first one

I have a couple suggestions that might help.

1) buy several pieces of tubing and plan not to use the first one or two. That will take the pressure off and make it more fun. It's not that expensive.

2) With my first couple (I've built 6 so that makes me an expert) - I took measurements and drew a little diagram like Mart's and then bent my tube to the diagram. Then you just tweak it a little after it's in place. You just need to take a couple height measurements and a couple length measurements. If you're interested, let me know and I can go into more detail.

3) The short 11/32 tube Brian mentioned is a MUST

4) If you make sure the flex is in the tube when you bend it, it will not kink

5) Heating the tube with a torch makes things ALOT easier. Heat only where you want the tube to bend

6) Only do gradual bends- otherwise the flex will not turn freely and this will bleed off speed and prematurely wear out the stuffing tube and the flex. It can even cause the flex to break.

Hope it helps. Have FUN!!

martno1fan

I dont know what you guys do to your tubes but i allways bend them by hand and ive not messed one up so far .Now watch me go mess my next one up after that statement .Great pics Brian,i know you like red but i was hoping for a few pics of the black (green) one .
Mart

BMAD01

Obviously that boat had another setup in it. It used to have a Quickdraw engine and a butch block. They both went away and the motor got moved forewards for this rebuild. I have never, nor will I ever heat up the stuffing tube to bend it. Just do it a bit at a time and recheck often. That way it comes out right on the first time. Brian

Dman, You can get K+S tubing from [email protected]

martno1fan

I think they sell that k&s tubing at your local DIY store over there i forget the name [sm=72_72.gif]

Dartman1074

Thank you again guys. I will be ordering the parts again and hopfully it all goes well

Dartman1074

Also do I need the linner inside the tube? or can it be just 1/4 inch tubing. I still have the old tube" that has the linner inside with a short peice of 1/4inch so it would fit in the skeg" I can make the short peice out of the bottom of the hull and then the 1/4 into that and back to the skeg

Paul M

Why do you have a problem with heating the tubes, Brian? I've done it on all of mine and never had any troubles, but maybe I've just been lucky.

BMAD01

Dman, I'm gonna throw a bunch of numbers at you, so read carefully. Your stuffing tube should be made from 5/16" od (outside diameter) tubing. That tubing has in ID (inside diameter) of .285". Your flexshaft has an OD of .250". Slide the flex inside the 5/16" tubing and there is .035" clearance. (.0175/side) Enough room for a good grease job. NO LINER NEEDED![:'(][:'(][:'(] The od of the 5/16" tubing is .3125". The id of the 11/32" tubing thru the hull is .314". Slide your 5/16" stuffing tube thru it and there is a .0015" slip fit. Perfect!
Don't start mixing used tubing parts with new ones. Put the old stuff in the garbage hopper and replace everything. This does not cost much at all to do, so just do it right the first time and be done with it. NO LINER! Brian

Paul, I don't like putting the torch to the tubing because I don't like messing around with the temper of the metal. If you bend it cold, the tubing is just as it was when you started and you haven't messed with anything. Some guys like to act like their metalergests (not you of course) and heat/cool the tubing. I just leave it alone and do it cold. Guess what? I've never had a problem either!

Paul M

Thanks Brian. Given your machinist back ground, I figured it would be some thing like that. Makes sense, but like I said until it causes me issues, I'll probably continue to torch my stuffig tubes

I agree on the liner. It isn't needed and is just something else to mess up and/or wear out

martno1fan

Hey Paul just remember dont bend that heated up tube over your knee [X(] [sm=spinnyeyes.gif] .
Mart

monsterbrad

Here is another tip for bending the steel tubes.
Drill a clearance hole in a 2x4 clamp the piece of board in a vice and slowly make the bend you need by sticking the tube into the hole in the board.
You can heat the tube also but make sure you have good gloves on.
This is the way I did it.

Jamming

You can also put a piece of duct tape over one end fill it with sand and bend it in a circle if you want and it wont kink.

Paul M

Exactly. Ouch

mechnique

Hi,
New to RC boating understand all of the procedure BUT what seals the inner tube to the epoxied outer tube - heat shrink?

noisy

hi..down here we dont use an inner tube...i just use the brass tube outer...but i use a tube greaser..just before i drop the boat into the water a couple pumps with a grease gun and away it goes ...in over 20 years newer destroyed a stuffing tube.....