Strut bushings

[Rcsurfrider]

what are people using for strut bushings these days? My ovalmaster uses ⅛ strut. Im currently using the diy bras tube cross drilled system with a bronze bushing I scalped from a motor. Need a new one now so?
Cheers

[Rcsurfrider]

Strut bushings

So guess Im just building the same bushing again.
I use oilite motor bushing from a 540 motor. I used to pop em out and put bearings in all the time so a few kicking around.
I press it into a brass ¼ k&S tubing after turning it down on my lathe to fit tightly then use sleeve retainer as press it in. The other pieces will also be glued in and cross drilled after gluing . I will use cooling fluid during drilling so I don't destroy the sleeve retainer bond. I will have small teflon washing between the drive dog and strut bushing end.





All done

[CraigP]

Bushing_Assembly_Inside.jpgBushing_Components.jpgStrut_Assembly.jpgStrut_Bushing_Assembly.jpgStrut_Components.jpgLooks like you and I are going down the same path... I have a Speedmaster 21 strut on my 34" Hydro with a flex shaft, no liner. The problem with the parts they give you, is that there is no way to allow for the 0.175" of space you need between the strut and the prop shaft dog, to take up the shortening of the flex shaft under heavy load. The bushing that came with the strut seems to be suited for a straight shaft, where you can use thrust bearings and collars to set up the proper end-to-end clearance. I ran the boat with the space cut down to 0.075", and the boat started to plow on the bow, due to the shaft moving the strut to positive thrust angle. I set it up to the right clearance, and the bushing nail head just falls out of the back of the strut, making for horrible side-to-side play! I solved it by modifying the components as the pictures show. I placed the original strut bushing into a piece of 1/4" copper tube and soldered at the appropriate place. I put a hole into the side of the copper tube to put a 6-32 grub screw in to seal the hole and keep the strut bushing assembly in place. After the run, I just take out this screw and squirt some lubricant in there. Now the shaft can move up as it needs, and the strut bushing stays wear it should. It ran like a champ!

[RandyatBBY]

I have always used Ball Bearings, this is my newest setup in a Stainless steel strut.

[Rcsurfrider]

[ATTACH=CONFIG]152561[/ATTACH][ATTACH=CONFIG]152562[/ATTACH][ATTACH=CONFIG]152563[/ATTACH][ATTACH=CONFIG]152564[/ATTACH][ATTACH=CONFIG]152565[/ATTACH]Looks like you and I are going down the same path... I have a Speedmaster 21 strut on my 34" Hydro with a flex shaft, no liner. The problem with the parts they give you, is that there is no way to allow for the 0.175" of space you need between the strut and the prop shaft dog, to take up the shortening of the flex shaft under heavy load. The bushing that came with the strut seems to be suited for a straight shaft, where you can use thrust bearings and collars to set up the proper end-to-end clearance. I ran the boat with the space cut down to 0.075", and the boat started to plow on the bow, due to the shaft moving the strut to positive thrust angle. I set it up to the right clearance, and the bushing nail head just falls out of the back of the strut, making for horrible side-to-side play! I solved it by modifying the components as the pictures show. I placed the original strut bushing into a piece of 1/4" copper tube and soldered at the appropriate place. I put a hole into the side of the copper tube to put a 6-32 grub screw in to seal the hole and keep the strut bushing assembly in place. After the run, I just take out this screw and squirt some lubricant in there. Now the shaft can move up as it needs, and the strut bushing stays wear it should. It ran like a champ!

Really nice design with the set screw.
My bushing is press fit (firmly) and set with med thread locker.
The main bronze oilite bearing is external on the bushing.
You need to heat it up with a pencil torch to break the thread locker to remove .
But it's only 1/8 shaft and .098 cable.

[Rcsurfrider]

I have always used Ball Bearings, this is my newest setup in a Stainless steel strut.

Randy that is sweet.
What size bearings did you find to use for that?
My ovalmaster is 1/8 shaft and .098 cable , but the b24 I plan on building up will be 3/16 shaft. Bearings would be nice. Although the TFL outdrive could be really cool too..
I guess it depends if I want a regular system for steerable strap system which may or may not be the best fit for the whole even though it looks scale appropriate?

[CraigP]

Randy, I was wanting to do the same thing, but couldn't find bearings. There's a bunch f metric stuff that is close, but was lazy to machine anything! So the shaft can move freely in the copper tube and the tube is held in place by the inner races of all the bearings in line? Did you have to bore out the hole in the strut to accommodate the bearings? Very nicely done!

[CraigP]

RC, is that a flex shaft or straight shaft? I don't see any take up space between the strut and the prop dog... That was the problem I was trying to fix... my flex shaft winds up at least 0.15" under heavy acceleration.

[Rcsurfrider]

RC, is that a flex shaft or straight shaft? I don't see any take up space between the strut and the prop dog... That was the problem I was trying to fix... my flex shaft winds up at least 0.15" under heavy acceleration.

It's flex shaft, the There is plastic washer that has a bend in it like a ) it flattens when the cable tightens. I have checked to make sure there is some slack but it is hard to see.

[CraigP]

Yes I see that... But my flex shaft is winding up much more than that. It accelerates really hard on 8s. I like that bearing setup you got! It's neat to see different people's solutions to problems. It's what I like about this forum...

[CraigP]

Randy, what distance do you set your prop dog from the back of the strut?

[kfxguy]

The bearings you need for a .187 flex is a r156 (there's different variations of that number depending on if it's sealed or not). I get mine from boca.

[ray schrauwen]

Interesting....

[ray schrauwen]

[ATTACH=CONFIG]152561[/ATTACH][ATTACH=CONFIG]152562[/ATTACH][ATTACH=CONFIG]152563[/ATTACH][ATTACH=CONFIG]152564[/ATTACH][ATTACH=CONFIG]152565[/ATTACH]Looks like you and I are going down the same path... I have a Speedmaster 21 strut on my 34" Hydro with a flex shaft, no liner. The problem with the parts they give you, is that there is no way to allow for the 0.175" of space you need between the strut and the prop shaft dog, to take up the shortening of the flex shaft under heavy load. The bushing that came with the strut seems to be suited for a straight shaft, where you can use thrust bearings and collars to set up the proper end-to-end clearance. I ran the boat with the space cut down to 0.075", and the boat started to plow on the bow, due to the shaft moving the strut to positive thrust angle. I set it up to the right clearance, and the bushing nail head just falls out of the back of the strut, making for horrible side-to-side play! I solved it by modifying the components as the pictures show. I placed the original strut bushing into a piece of 1/4" copper tube and soldered at the appropriate place. I put a hole into the side of the copper tube to put a 6-32 grub screw in to seal the hole and keep the strut bushing assembly in place. After the run, I just take out this screw and squirt some lubricant in there. Now the shaft can move up as it needs, and the strut bushing stays wear it should. It ran like a champ!

I have always wondered if the collar on the end of the speedmaster bushing should be inside the aluminium strut Oron the outside?

I've been running them on the outside for years and may change this now after seeing your post.

Thanks.

[Rcsurfrider]

Yes I see that... But my flex shaft is winding up much more than that. It accelerates really hard on 8s. I like that bearing setup you got! It's neat to see different people's solutions to problems. It's what I like about this forum...

8S I bet it does. I ight have to revisit my gap on the drive dog now that I look at it closer. Have not run yet since I made the new bushing.
My ovam21 is running a vintage 2002 Lightning Man Neo 05 motor not quite the same power plant although very torquey motor. It is difficult to turn the shaft by the prop it cogs so much, still a very fast boat especially with x438 prop on 2s.