Proper Use of Sleeve Bushings

[DISAR]

Jeff -

Ok, I have the speedmaster 21 strut, 3/16 flex and prop shaft, 1/4" stuffing tube without teflon. The 1/4 tube slides into the strut nicely for about 3/8" as you said and heatshrink in the connection.
So for this case your bushing is made of 7/32" tube (entering slightly the 1/4") with a piece of 9/32" tube at the end. Is that right?

[Doug Smock]

Dimitrios,
If you'll dress the 1/4" tube a bit (sand it with 400 grit) it will slide completely through the strut and you'll be able to use it as it was intended.

Doug

[Jeff Wohlt]

Nitro....they need the support (IC motors) and use the larger struts...they were designed that way. I can show you also where they ran the hole out the back and it is open for water to come in so they could adjust there struts.

This comes down to a few nitro struts made to run FE. That is about it. Nothing to do with teflon bearings as most do not run those anymore anyway. They wear and do not give the support a true bushing does the length of the shaft. How many records have been set using Fullers hardware?

The reason our bushing is not meant to spin inside the strut is because it will wear the strut hole larger. Jays method is spinning brass in brass.

So please do not let this confuse you as it is two different methods. One for large dia noses and the the normal smaller 3/16" nose.

[Jeff Wohlt]

Dimitrios,

My speedmaster strut does have a bushing in it and I did not put it there. The 1/4" should go thru unless something else is in there.

[Steven Vaccaro]

Cool topic.

Jay is 100% correct about Speedmaster struts. The bushing slides into the 1/4" stuffing tube the goes into the strut, if you run it that way. Also note that the distance between the drive dog and strut has to be less than the width of the collar on the flanged Speedmaster bushing. Otherwise it can come out of the strut and cause issue(found out the hard way ).

I run a Speedmaster 21 strut with a flanged bushing and with a smaller 7/32" stuffing tube. So I dont have the option of allowing the bushing to spin within a 1/4" stuffing tube. So I do put a dab of CA on the bushing. It does work. Otherwise if I didnt put the glue the bushing will wear out quickly(found out the hard way).

As far as Teflon bushings go. I have been selling the Solinger system for years with lead teflon bushings. Everyone so far loves them. The bushings do need replacing from time to time.

[Jeff Wohlt]

All nitro designed struts do the same. Stuffing tube goes all the way thru.

The teflon coated bushing as Paul and most other struts use do very well when wet. The layer of water is the key. Paul and I have had this discussion and he really is on it as I looked some things up about our conversation and is was right on. Just do not run on the bench much.

My dad was an engine mech for big war ships thru the last WW and Korea...he will tell you water was the best lube. Beats me but I have to believe him since he is my dad and now 83 and was on ships from 17-28 years old. Many lied about their age to go to war...go figure. People that wanted to go fight!!

Solinger, Fuller, Hughey and many more have used these for years. Most of the problem was I had struts with one teflon bushing at the end....so I used to cram two to three down it to support the shaft better. Now I just make a replaceable strut bushing for all my rigs. I need the stuffing tube as small as I can get it. Do not run a 130 or 150 in a 1/4" brass tube without teflon...it is too larger and will whip like hell.

We are talking two different types here. Both are very simple. I prefer the smaller stuffing tube but again, I use mainly wires. If you run 150 cable you can run 7/32 stuffing tubes and shim the nose down with KS. Bigger the stuffing tube the more drag is has for open stuffing tubes such as hydros and single motor cats running one motor.

I love the smaller stuffing tube. With .062 I run a 1/8" stuffing tube. I also turn noses on the lathe to fit the unit.

So, The Vegas, UL, SV, speedmaster and a couple others are made to slide the strut up the stuffing tube. I just prefer a smaller stuffing tube for less drag.

Okay, good stuff but I am burned out on this one.

[paulwilliams]

My dad was an engine mech for big war ships thru the last WW and Korea...he will tell you water was the best lube. Beats me but I have to believe him since he is my dad and now 83 and was on ships from 17-28 years old.

Central heating pump impellers run in a water bearing. If the thermostat fails on the boiler and boils the water too hot, the impeller will expand and jam in the housing.

The pump turbines on NASA's rocket engines are lubricated with the very thing they pump: liquid oxygen @ ~ -250 Celsius!

Modern car engines run for 100,000+ miles with minimal servicing and wear, partly thanks to modern CNC manufacturing, but mainly because modern lubricants are so good.

It's an interesting subject.

Paul

[Jeff Wohlt]

Not sure this is a fact but I heard in the early years the PC harddrives had a water bearing of some sort.

[Flying Scotsman]

A cautionary note this info does not apply to a stinger setup. EDIT OK, I threw this out for an answer, so you young pundits. Right or Wrong .......Dr.House Torrance

Douggie

[Jeff Wohlt]

Well the bushing does fit in the stinger strut just fine. As noted ANY strut with a 1/4" hole will fit either. Depends how you want to set you boat up. I try and use as little of stuffing tube as I can. Not sure what the other stuff means.

[DISAR]

I had a closer look at my strut and bushing yesterday and I can say that for the Speedmaster 21 strut the 1/4" stuffing-brass tube slides in all the way and the bushing slides in the stuffing tube nicely. Therefore what Fluid advised is correct when using the 1/4" stuffing tube. In addition, I noticed that the bushing is just a brass tube 7/32" with holes and a piece of 1/4" soldered in the end. Very easy to make.

[DISAR]

Cool topic.

I run a Speedmaster 21 strut with a flanged bushing and with a smaller 7/32" stuffing tube. So I dont have the option of allowing the bushing to spin within a 1/4" stuffing tube. So I do put a dab of CA on the bushing. It does work. Otherwise if I didnt put the glue the bushing will wear out quickly(found out the hard way).

When running with a 7/32" stuffing tube you can cut it before the strut and solder a piece of 1/4" that will go into the strut, provided that there is enough space before the strut.

[Shooter]

Is it a problem when the strut bushing slides axially? Mine not only rotates, but slides back and forth within the gap that I allow between the drive dog and strut end? It usually ends up at the drive dog end because of the pitch of the flex cable windings. Does anyone else experience this? Is this a problem? Thanks.

[properchopper]

Is it a problem when the strut bushing slides axially? Mine not only rotates, but slides back and forth within the gap that I allow between the drive dog and strut end? It usually ends up at the drive dog end because of the pitch of the flex cable windings. Does anyone else experience this? Is this a problem? Thanks.

Shooter, I'm experiencing the same situation on one of my boats that was set up by the person I bought it from. My thinking is that it shouldn't be a problem; if any forward force exerted on the bushing is created by flex windup it will just push the bushing back forward given that the bushing is free enough to slide in either direction. I do lube after every day's run, BTW.

OTOH, I just set up a hydro with one of Jeff's .078 wire drives which includes his ball-bearing strut and believe this is a great way to reduce parasitic driveline drag.
I grease & lube after each day's run as well and am just thrilled with this setup.

[Shooter]

Thanks. I guess what I am really concerned about now is the fact that the flange on the bushing can come completely out of the strut which eliminates the centering feature. I think I just need to head up to the hobby shop and take a look at a new one. I'm not even sure if the flange should be into the strut or not. Anyways, when the flange slips out, the bushing is cocked slightly in the strut. This can't be any good?? huh??

Where did you get the ball bearing strut? Thanks.