WIRE DRIVES

[gil sonsino]

Once FE guys use wire drives at very high rpm's (50.000rpm) why not stick to them with small nitro blocks? I do know they can be used even with small bends!

Gill

 

[hugh hargett]

Gil , playing around one day I noticed that a 5mm to.078 electric collet will fit right onto a small nitro motor .15-21 without any problems with a nice snug and true fit. It is quite possible. Havent seen it yet, but I have 3 car nitro motors I cant seem to even give away, so enventually I will buy some small monos,under 30 inches, and do just what youre speaking of.

Hugh

 

[gil sonsino]

I do know that Glen Quarles(Novarossi USA) has use them in some of his boats sucessfully but no more details.Make a collet is not a problem but I would like to know how they hold the power as they have much less drag than flexshafts.I'm about to build another Jae .45 for saw and wonder this is a good way to improve things.

Gill

 

[hugh hargett]

I dont know if the bend needed for a Jae will be good for a wire. Too much bend and they will put alot of side load on your bearings/bushings. Note I do have a .078 wire in my dumas 20 pak and im expecting it to hold up under 3500 watts or 4 and 3/4 horses. I have a good bend in it but I made it very long(motor far foward) to ease the side load pressure. I think It will hold up just fine on say a 21. Mind you Im not up to date on what kinda horses guys are putting out with .21's theses days. Gil i do not like the loctite method . How would you secure your prop shaft to the wire?

 

[gil sonsino]

Hugh I plan to build the new boat with no bends on the drive line as it will be for saw .I never tried wire drives on my boats that's why I'm asking for this option on nitro boats as I see less drag to power .Most of new .21 engines deliver something around 2,8 hp.If I would try wires I would use low temp siver solder instead of loctite.

Gill

 

[Glenn Quarles]

Gill, yes I have been using the wires for years. That is the only thing I will put in a .12 boat. My latest .21 boat also has a wire that Charle Perdue made for me. He has really perfect the wiredrive in the bigger boats. They work great, have much less driveline drag, and are holding up fine with the bigger motors. You will want to put some bend in the wire!!! You need to force the wire to bend one way or it will whip all over the place! The bend in the stuffing tube in very important...it must match the natural bend the wire takes from the motor collet to the front of the strut! You will also want to run ball bearings in the strut. I think Charles is using something like .125 wire in his .45 boat (I have .062" in the .12 and .078" in the .21). There are no commercially available collets for ther bigger wire sizes that I know of (I stock the one for the .062").

Glenn

 

[HOTWATER]

Do it guys!! A gradual shallow bend should not hurt at all. Get in touch with Jeff wohlt www.rcraceboat.com

he will be able to help you out with collars, wires and any questions you may have...he is the "wire drive guru"...

-Kent

 

[TinoAlmanza]

I ran a hull with stuffing tube that came out of the hull about an inch then open wire to the strut. It was the fastest boat I owned. I got the idea from a post by one of the overseas SAW racers.

 

[HOTWATER]

Yep...and you can also seal that gap between the end of the stuffing tube and the strut with shrink tubing to seal out any water from entering and going up the stuffing tube...

-Kent

 

[gil sonsino]

Thanks guys it's time to roll over the sleeves and start new things.

Gill

 

[Martin Hamilton]

Wire drive is the way to go with ball bearings in the strut,i run one in an electric JAE Mini Sprint hydro with .048" piano wire into a 1.2mm collet coupling.You must have a curved stuffing tube to stop the wire whipping but not to much as youll put side load on the motor bearings & strut bearings.Iknow a lot like to run their flexes just in the brass stuffing tube & no teflon liner as the flexes can tear up the liners & destroy flexes but ive found with wire drive they like to run with the teflon liner in & the wire shouldnt tear up the liner either as theirs so much clearance between the wire & liner. Apart fron the one place the wire is touching the liner ie the lowest point of the bend in the stuffing tube+ the wires smooth unlike the stiraled flex.Some setups wont take wire drives it all depends on engine position & height + length to the strut & depth of strut determining also how much curve you end up with in the stuffing tube. On some electric boats the motor is more towards the rear of the boat so as to get heavy batteries & speed controller in the front of the boat this makes it almost impossible to use wire drives but nitro guys shouldnt have this problem as your motors are further foward. You get much less friction with wire + a lot less rotational weight over flexes. Martin.

 

[Martin Hamilton]

The mention of open wire drives,I run tethered hydros(ic engines)in the UK for more than 40 years the open wire drive is the standarded system used & has been for many many years longer than ive been involved.But we use thick piano wire that is straight with a ball type coupling connecting to the stub shaft in the strut. 3.5cc use 1/8" piano wire up to 10cc around 3/16" every thing is custom made hardend & tempered.In the strut we use bronze bushings & not ball bearings as the struts would be to large diameter with ball bearings + the ball bearings dont take the loads put on them (i used to run ball bearings 30-40 years ago with success but went to bronze but we dont have lube problems on the bronze as theirs an oil way in the strut that holds a small amount of oil & we only run for around 30 seconds + starting & launching. Martin.

 

[gil sonsino]

Good info Martin and thanks for your explanation.The boat I'm building is a JAE 45 FE for SAW with a big electric motor 5692 so I intend to keep everyting aligned with the possibilty of a 4mm wire drive..let's see ! In the early 70's all my boats are equipped with rigid treated shafts and bearings on struts so it won't be difficult do make some tests with different dia. wires.

Gill

 

[hugh hargett]

Gil if you are going to run .062 wire you may opt fot a 3/16 stuffing box and teflon for .098 cable. I think to be on the safer side of things you run a .078 - .092 wire. Have a look at this thread too: http://www.intlwaters.com/index.php?showtopic=49386&st=15

 

[gil sonsino]

Hugh I think .92 is the safer side as I will run 8S.Thanks

Gill

 

[hugh hargett]

We got a bit off topic there but chris runs extremely strong and he has a take on wires versus cables thats worthy of consideration. Not trying to turn you away just sharing some others experiences. I too like wires. I run both though. I like wires but Id feel alot better if some one came up with tapered ferrule for them. I worry about the heat on the wire with the the silver solder and I dont really like the locktite. I do have a p hydro with loctite thats has held so far on about 1.5hp.

 

[Martin Hamilton]

You realise how strong the bond is on Loctite 603 when you have to remove the wire from the stub as i had to recently. Heat is the only way to break the bond even then i struggled to get the wire out even once id broken the bond & it was turning it was still very tight twisting & pulling at the same time. Bearing in mind this was on a very small diam .045" wire. Re brazing/silver solder on piano wire you have to be very carefull with the high temps required as you will soften the spring steel wire.

 

[Martin Hamilton]

If your going to use a wire drive with ball bearings in the strut fit 2 ball bearings in the strut at the prop end to take the torque loads otherwise youll knock the bearings out pretty quick. On smaller motors you can use 1 ball bearing at the front end of the strut, larger more powerfull motors need 2 ball bearings at the front & 2 at the rear of the strut.

 

[gil sonsino]

Martin yes I will be using 2 or 3 ball bearings in the strut and one in the midle of the stuffing box to avoid the wire flexing.I made some tests with this set up and looks it holds this power...... power of a 1700Kv motor on 8S is huge! It would be nice have some pics of this system....

Gill

 

[hugh hargett]

You realise how strong the bond is on Loctite 603 when you have to remove the wire from the stub as i had to recently. Heat is the only way to break the bond even then i struggled to get the wire out even once id broken the bond & it was turning it was still very tight twisting & pulling at the same time. Bearing in mind this was on a very small diam .045" wire. Re brazing/silver solder on piano wire you have to be very carefull with the high temps required as you will soften the spring steel wire.

Noted Martin thanks

Gil as we spoke before as long as the bend is gradual or the wire is long the side load on the bearings can be minimized. Also if you can find a better grade wire than k&s do so, coz you have to search through the box to find good straight pieces.

Martin what id want is a two pieces of stainless tubing one3/16 with a 1/8 id the another 1/8 with an id of my wire then through-hole to the wire and lock it in place with the set screw of the drive dog and a set-screw propnut 180 opposite of one another, But the best thing would be a wire ferrule.

Also could the wire be dipped in oil after recieving heat from the soldering process?