Square drive systems

I have been thinking about setting up my .21 rigger with a square drive system. Do you guys that run them pick up any speed or is it mainly to save wear and tear on your engine bearings? Does it work best on smaller motors or are there benefits with boats of all sizes?

Bob:

I have run this system on many 20 boats and love it. I also ran it on my 67 boat with 1/4" cable and it was really good. I believe that I saw performance advantage on the 67 boat. Can't really say I did on the 21 boat but loved the way of maintenance and ease of removing the engine after running. I think that it must be better for bearing life.....

Thanks Marty,

That was actually my son Greg, but we are working together on this. I suggested he post the question about performance before we try a square drive. There is a fellow making cables squared at both ends now. I just need to know where to get the engine and stub shaft collets. Where do you get yours?

Seems like you need to run a shaft oiler, like the ones Steve Wood makes, since the stuff tube is open a the bottom. Is that what you do?

Bob

Bob:

I have never used the square on both ends so I can't comment on that. I used the solder on ferrule and really liked it.

Hey Bob,

Like Marty, I have run square drive for years with the soldered on Octura collet on Sport and 67 Scale boats. Looks to me that you would have to remove the square drive collet on the stub shaft to get the cable out of the hull, I prefer the flexibility of making up shafts as I need them rather than having to measure them and send them out to have the bitter end squared.

I use a stand pipe oiler for the cable, and two roller bearings in the strut which I grease wilt a small pin point grease gun.

I have used Square drive collets and one end squared cables from Lenny Blake at www.rumracingproducts,com for years. Only other one I have used came from Elite (black one in the square drive options pic) I got their address from Marty's site but that was quite a while ago now. Aeromarine makes a square drive insert to replace the regular insert for the compression style cables, but it is made out of brass and I wouldn't think it would hold up. Would still require the tightening of the Aeromarine collet to hold the insert in place - I don't care for the additional moving parts. CHEERS !!! Bob

I have all the stuff you need...I believe you will see performance advantages, especially with .150 cable on a 20 size boat... Think about it...slinging that .187 cable compared to .150... You have to give me a cable length, but you have no solder joints to fail...if that joint fails, guess what? You just lost your prop... I can turn around your order in one day and ship it out. Just takes a moment to measure and give a call or PM to order...EASY!!!

Plus, if you order the whole system, I will include a second cable, free

Bob,

Your statement about the solder joint is incorrect. The brass Octura ferrule is silver soldered to the one end squared cable and attached to a 3/16th case hardened stub shaft with two set screws. The prop is not lost. See attached pic in above post showing strut, stub shaft, ferrule with two set screws.

Where are .150 square ferrules available from?? Do you use 3/16" stub shaft compatable with most . 21 size props or something else? CHEERS, Bob

Ok...maybe the prop isn't lost, but could still fail. I have the ferrules made. I have .150 .187 and .250 ferrules. The .150 and.187 are bored 3/16 to accept a 3/16" stub shaft. .250 bored for 1/4" stub shaft.

Lets not forget the Teflon washers used as a thrust bearing, of sorts.

Have run this on my .21 rigger and it works great for that small eng.

I use a standard flex shaft that is squared at the drive end then use a standard brass bushing setup in the strut. I use a Teflon thrust washer between the drive dog and strut.

At the eng side I put a collar on the shaft to keep it from falling out . the drive collet is from K&B.

Real simple to maintain just loosen the collar and remove the shaft to grease.

This can be used with any boat with all the stuff already there. no reengineering of the whole drive line.

gust cut a standard cable to the right length and have it squared. the K&B nuts are real small and top quality.

Thy make them 3/16 and 1/4 .

Bob,

Not sure your .150" cable is faster, have you done any back to back tests to prove

that?

Just Wondering?

Mark Sholund

Hey David,

I don't grease mine but use an oiler. At the end of the day, I pull the flex shaft with attached ferrule , hose if off with WD 40 then drop it into a tube filled with ATF fluid between races.

I have never had a silver soldered Ferrule joint fail in the 22 years I have run this setup. Lost one prop on a Scale boat when the stub shaft broke where the prop nut threads started.

Roger your thoughts about .187 vs .150 flex cables Mark S. CHEERS !!! Bob

Guys, I'm sure what has worked for you for years is fine. This system is good too...it's been around district 9 since the 80's and now I'm providing it to the whole rc boat world. You don't "re-ingineer" the drive cable. It's a good system, particularly when a new boater is not good at soldering cables to ferrules. I have not done a "side by side" test, but the drag would have be to less with smaller cable. Suit your self and stick with what works for you. If I can help you with a drive system, I'd be happy to do so.

To expand on my thought here...I'm providing an alternative to the clamping style hex and one piece cable with a welded stub. Not so much the old school octura brass ferrule. I'm honestly surprised octura is still around, glad though that they are. You won't lose a prop with that system, but with a cable clamp style hex and welded stub shaft, you could possibly lose your prop if the cable breaks...again, if I can help you, great. Thanks, Bob

Dasboatman said:

Hey Bob,

Like Marty, I have run square drive for years with the soldered on Octura collet on Sport and 67 Scale boats. Looks to me that you would have to remove the square drive collet on the stub shaft to get the cable out of the hull, I prefer the flexibility of making up shafts as I need them rather than having to measure them and send them out to have the bitter end squared.

I use a stand pipe oiler for the cable, and two roller bearings in the strut which I grease wilt a small pin point grease gun.

I have used Square drive collets and one end squared cables from Lenny Blake at www.rumracingproducts,com for years. Only other one I have used came from Elite (black one in the square drive options pic) I got their address from Marty's site but that was quite a while ago now. Aeromarine makes a square drive insert to replace the regular insert for the compression style cables, but it is made out of brass and I wouldn't think it would hold up. Would still require the tightening of the Aeromarine collet to hold the insert in place - I don't care for the additional moving parts. CHEERS !!! Bob

Click to expand...

Hey Bob:

In the one image showing underneath boat, shaft-log, Octura flex-ferrule and strut, how are you able to remove flex-shaft? There's no space between shaft log and strut. Curious?

David, both the octura ferrule and my square drive ferrule are joined to the stub shaft with set screws...loosen set screws and shaft assembly slides out the trailing edge of the strut blade.

Bob T.

Here is a tip for all of you using the soldered on system. Solder on the tapered end using StaBrite and then when cool put a short length of 3/16" rod in the collet and tighten the set screws. Put that end in a lathe or drill and take a short piece of brass tubing to hole the shaft while spinning. Place a torch on the soldered joint and it will go perfectly smooth when you melt the solder. Let cool and you have a really smooth and straight flex shaft.

Thanks Martin. I was going to ask that very question.

Olly

David,

I leave a little bit of forward play on the square drive end so the flex cable can move forward maybe 1/8" or so. I file flats on the stub shaft to line up with the two set screws in the Octura ferrule. To assemble: clean the inside of the Ferrule, flats end of stub shaft, remove and clean two set screws and the two threaded holes of the Ferrule. Eye ball the flats lined up with set screw holes, place a drop of blue Locktite in the threaded hole, run in a set screw ensuring that it picks up the flat and tighten it. Second drop of Locktite in second hole and tighten set screw.

At the end of testing or after a race, back out the set screws, twist the stub shaft using prop as lever arm, and back the stub shaft out the rear of the strut. You should be able to get the ferrule outside the diameter of the strut bottom and pull the flex shaft with attached ferrule out the rear of the stuffing tube. Flush the roller bearings in strut, flex cable with WD40, dry off the WD and lubricate the roller bearings. Drop the flex cable into a PVC tube sealed at one end and filled with Automatic Transmission Fluid (ATF) put a PVC cap over the other end and keep that end vertical or you'll have a slimy red oil slick where it spills.

Sounds like a lot of work, but lots easier than pulling a compression style cable collet, greasing the shaft and putting it back together after every run. CHEERS !!! Bob

Hey Marty,

You technique beat the Sam Hill out of the jig I have been using for years. Certainly follows the K.I.S.S. Principle. Thanks for sharing, Mate. CHEERS !!! Bob

]Guys,

I am setting up my first square drive on a 101 hydro using a hardened steel stub shaft running in needle bearings. My question is, what is best to use for thrust washers? I have some ball race bearings and I also have what looks like a moly impregnated plastic (teflon?) washer with two steel washers. See pics. What do you find works the best on bigger boats?