Jeff Wholt is building the smaller 3/16" stuff for .12 and 21 boats. Google Wholt RC boats
Brent Byers on Jim's is building 1/8" wire drives with 1/4" stub shafts.
The rest of us are making our own.
What boat size do you have in mind Doc?
Doc, in my 12 boat I have no bearing in the shaft log with a 0.062" wire and it works great.
On my first 21, I made a machined a bushing out of oilite material and slid it down to the middle of the shaft log. I put a counter sink in the strut end of the bushing so the wire will "find the hole" when first inserted. The problem was how to hold the bushing in place. I drilled a hole in the log close to the center point (inside the radio box), made a drill dimple in the bushing and then glued it in with JB Weld and sealed it all up. I wish I knew of a better way to hold the bushing in place that would allow for easy removal in case I want to switch to a flex shaft for some reason.
Having said all that, the two JAE 21s we are building are both GT versions, but we cut off the bait boxes to make them more like a G2. With the shorter wire, we may not need a bushing in the log. In fact the wire is about the same length as my 12's wire and it works great with no bushing. The downside of the shorter boat with the larger wire is that the bend is sharper than it would be with the full length GT tub. Upside is that we may not need a bushing. Have not tested any of this in the 21 boats yet.
Anybody have any ideas on how to simply hold the bushing in?
Bob, years ago when we ran solid shafts we used needle bearings in the shaft log
We held them in place using another brass tube that fit the ID of the shafts log between the bearing thus holding them in place. Easy to change bearings
BTW one can put TOO MANY BEARINGS IN THE SHAFT LOG.
Any thing that rotates has a SINE WAVE.
If the shaft is held to ridged the SINE WAVE energy will be dissipated at the prop snapping the stub/prop off.
The shaft becomes like a bull whip
I saw this phenomenon happen several times in the days of solid shafts. Even MR GEE solid shafts
Today Doc many of us run 1/4" Teflon tube sections spaced every couple of inches to support the wire inside the larger brass stuffing tube.
This is not the thin wall Teflon tube, but a thick wall variant that acts like a bushing to support the wire.
In all my wire drive boats, I use the thin wall Teflon tube as a long spacer in between the thick Teflon bushings to keep the bushings in place.
So long-short-long-short-long-short and so on.
here is a McMaster link to some 1/4 OD 1/8 ID tubing. https://www.mcmaster.com/1817t11
It's PEEK Doc. Poly ether ether ketone. If you want the highest performing plastic ask Bullard to machine you some Vespel bushings. You can also buy those from McMaster. https://www.mcmaster.com/vespel-polyimide-bushings
I am using both bushed and ball bearings. Bushed for the smaller struts with small wire like .062 and .078. Larger wire get bearings as the radial load from the wire trying to straighten out puts a lot of load/friction into a busing.