Dog and Bone Drive

[Ghosty]

Hi All,
Been building a new drive system for a new boat I will be building, the dogs are machined out of 316 SS bar, and the bone is hiding in the m12 316 SS bolt behind the bones. The one shown in the boat is one I machined up several years ago, it has a 3" spacing, the new one will only be 1" spacing.

Cheers
Andrew

 

[Ghosty]

Have the bone machined, now just to finish off.
Cheers
Andrew

 

[Ghosty]

Hi All,
Finished
Cheers
Andrew

 

[Cogsy]

Very cool. I'm not familiar with that type of coupling and just assumed it was something along the lines of a spline but now I see it's more like a uni-joint and allows for misalignment. Nice!

 

[Ghosty]

Very cool. I'm not familiar with that type of coupling and just assumed it was something along the lines of a spline but now I see it's more like a uni-joint and allows for misalignment. Nice!

They are use in a lot of RC cars as axels for the drive, I use this setup as the engine is rubber mounted and the gear box is hard mounted and is the easy way to do the drive setup.

Cheers
Andrew

 

[Brian Rupnow]

Thank you for that, Andrew. I have worked in engineering for 53 years and never seen that coupling design before.---Brian

 

[lohring]

At one time that was the standard drive for RC race boats. Today nearly everyone uses flexible cable or wire drives. They allow more adjustment with less power loss at an angle. The current RC boat record holder at 177 mph two way average runs a 2.5 mm wire drive. Its motor turns around 70,000 rpm and the boat has made one way passes over 180 mph.

Lohring Miller

 

[Ghosty]

This is the gearbox drive setup. Output is by twin counter rotating 1/4" flex drives.
I also use the same drives in my jet boats
Cheers
Andrew

 

[tornitore45]

Beautiful models.

 

[Ghosty]

Thank you for that, Andrew. I have worked in engineering for 53 years and never seen that coupling design before.---Brian

Brian, we are never too young to see or learn new things
Cheers
Andrew

 

[payner]

Andrew. First off very nicely done , now quick question.
I used to race nitro boats and was always under the impression that you put the "bones " at 90 degrees as you have done , I have now migrated to model trains and one of the aftermarket suppliers says the " bones " should be installed on the same plane when making a driveshaft.
Any thoughts / ideas
Bill

 

[Ghosty]

Andrew. First off very nicely done , now quick question.
I used to race nitro boats and was always under the impression that you put the "bones " at 90 degrees as you have done , I have now migrated to model trains and one of the aftermarket suppliers says the " bones " should be installed on the same plane when making a driveshaft.
Any thoughts / ideas
Bill

With these they are turning at 18+K rpm, I have found that when they are on the same plane, when they wear you get a lot of vibration, with them at 90deg, I have not had the same problem. I also use an alignment piece to help with the setup, seen in the photo, the alloy bar at the top of the photo.
Cheers
Andrew