1 of a kind 37" CF Dragboat

[srislash]

Are you going to do an S bend DJ or just the curve?

[olwarbirds]

Shawn, since the AOA is a bit limited due too tub depth, I will probably need to do a S bend. This will be a first for me. I usually make my stuffing tubes easy to remove for cleaning or replacement by using a piece of tube one size larger epoxied in hull, then I slide stuffing tube into it. A S bend if I understand how its done, would not allow me to do this. correct ? A link or photo of how to do a S bend will be a big help to me...

[srislash]

To tell you the truth DJ, it has been quite awhile since I have done one myself, most of my stuff runs reasonably straight. If you were wanting to have it removable you could do the next two sizes tubing up. The big size being real short and fastened to hull and the middle size being a bit longer with a collar soldered to the top side (possibly with a set screw) so it could not fall out the bottom. You pull the middle tube upward and this should give enough play in the larger tube to get the tube out.
Orrr... you could clean the tube with fuzzy hobby wire(name is not coming to me) and varsol

[flraptor07]

To tell you the truth DJ, it has been quite awhile since I have done one myself, most of my stuff runs reasonably straight. If you were wanting to have it removable you could do the next two sizes tubing up. The big size being real short and fastened to hull and the middle size being a bit longer with a collar soldered to the top side (possibly with a set screw) so it could not fall out the bottom. You pull the middle tube upward and this should give enough play in the larger tube to get the tube out.
Orrr... you could clean the tube with fuzzy hobby wire(name is not coming to me) and varsol

That would be a "Pipe Cleaner"

[flraptor07]

Shawn, since the AOA is a bit limited due too tub depth, I will probably need to do a S bend. This will be a first for me. I usually make my stuffing tubes easy to remove for cleaning or replacement by using a piece of tube one size larger epoxied in hull, then I slide stuffing tube into it. A S bend if I understand how its done, would not allow me to do this. correct ? A link or photo of how to do a S bend will be a big help to me...

I usually run S bends on most of my builds, less flex cable whip and they run quieter. The way I do them is heat the tube to almost glowing and let it cool naturally, that makes it more plyable. Then I fill it with fine sand, pack it tight, cap the ends and bend away.. Empty the sand when done and clean well..

[srislash]

That would be a "Pipe Cleaner"

Thanks Chris. Just had a brain fart thinking about the fancy tube dealy. ;-)

The sand is the way I do my bends as well.

[olwarbirds]

hahaha you guys are great... using sand good thing to point out, we use to do that back in my nitro boat days. So looong ago I had forgot about it. Bending is not a prob for me its how you do the S bend, could someone pls post a pic of a stuffing tube done in a S bend...mine would be a very crooked S, it would come straight out of offset strut then curve to port then curve up to go in hull then curve back down to keep AOA low... Yikes !!! that even sounds scary... am I thinking this right ?

[srislash]

It doesn't have to be buddy. If it is an S bend then you keep the motor parrallel with hull bottom as well as with strut. You also don't want the motor offset so much that the port side sits underwater. I see the hard part being whee the hole for tube goes thru.

[olwarbirds]

I did alot of measuring and laid it all out. The offset difference is actually 3/4" ...so the bends in stuffing tube wont be that severe. I will start mounting hardware tomorrow evening. I need to order that KR-XLong motor mount, I think having the motor and mount just setting in place will help me get this lined up perfect first time...

[srislash]

I had a look at my 'Doug Thwaits' rigger and the S is not that severe either DJ. Not even really sure how even the curves are with each other. Hard to tell when mounted. I always assumed the curves should match(but opposite) for efficiency. Like when setting up U joints on a vehicle.

[srislash]

And to add to that last statement here is a link to the debate http://www.rumrunnerracing.com/fefor...p/t-29567.html

[flraptor07]

You can kinda get a idea of how it's bent here, the outside is pretty much the same but longer. DSC02843.jpg

[olwarbirds]

Tks Shawn, interesting read... Dang Chris, you do build nice looking layouts brother, your hotrodding showing thru your boats too...does that servo have a chrome cover on it ?...tks guys, I get it better now...do you run liners ? I normally dont, but this is my first boat that I'm going to be using a .250 flex in... DJ

[srislash]

I kind of got away from them myself, I meant to run them on the R-42 but... I am going to on the HPR. Just to quiet it down and I hear it is better for high rpm.

[jcald2000]

Teflon liners will tie themselves into a ball in a high powered race boat over say 4s power.
I have witnessed 3 doing just that, costing shaft, strut tube and in one case the bottom of the boat.