Run in stand/dyno build.

[BobHorowitz]

Nice

 

[Terry Keeley]

Pin now 0.200" with flats, up from 0.160". Also saw that Speedmaster had 5/16" collets and nuts so I upped the shaft size while I was at it.

 

[RaceMechaniX]

Terry, does the pin float or is it pressed into the main shaft?

 

[Terry Keeley]

Terry, does the pin float or is it pressed into the main shaft?

Press fit. Dunno why CMB's floats other than it's easier to make?

 

[RaceMechaniX]

Terry, I assume it is to allow more angular misalignment between the two parts and reduce wear on the pin. When the drive pin is free to rotate along its own axis it will self align to the flats in the female coupler. When the pin is locked, the flats rock instead of slide and will wear into the sliding surfaces. Your set-up is pretty close to dead nuts aligned so hopefully it's not an issue, but I suspect with engine vibration, crank flexing, etc, you will see some more wear compared to if the pin were floating. Just my 2 cents.

-Tyler

 

[Terry Keeley]

Burned two gallons (15 runs) yesterday, so far so good but I only got to 18K.

Looks like a wide contact area, maybe that'll be the fix?

 

[Terry Keeley]

Think I'm ready for the dyno wheel finally. The large R12 bearing that holds the female U-joint was fit too tight and the cheap Flee-bay oilers were causing problems, both fixed and now she's smooth as silk.

My buddy Rudy said it would be cool to see some slow-mo video to see how the crank moves around...

 

[Terry Keeley]

I was able to zoom in on the flywheel area, man that crank flexes!

The whole stand is moving around!

 

[Terry Keeley]

Getting ready for the next phase...

 

[Alan Elzer]

Lookin good Terry

 

[Terry Keeley]

Did an initial test of my fan setup, not easy running a motor indoors in the suburbs, lol.

Camera angle is bad on the video but you get the idea.

I gotta vent the Byron fan away from the exhaust fan, won't be a problem with the dyno wheel of course.

 

[John Beardslee]

Did an initial test of my fan setup, not easy running a motor indoors in the suburbs, lol.

Camera angle is bad on the video but you get the idea.

I gotta vent the Byron fan away from the exhaust fan, won't be a problem with the dyno wheel of course.

John Bridge used an automotive muffler mounted in a basement window, replaced the glass with sheet metal.

 

[dave roach]

One thing about it that fun is getting well lubed.Terry That pipe is that going to you bed room.LOL

 

[Terry Keeley]

One thing about it that fun is getting well lubed.Terry That pipe is that going to you bed room.LOL

Plugged the hose into one of the sewer vents and blew it right out the roof!

 

[Grimracer]

it will.. no question.. oil your shop..

Keep us posted

Grim

 

[Ricky Neal]

This is a great thread full of some great info, I have been trying to figure out how I can build a dyno for my hydro engines and this will help a lot. Thank you.

I do not run RC hydro's at the moment and instead, I run tethered hydro's. - I have not read every part of this thread but saw that you had issues with couplings failing, This is something I have had while running tethered hydros but I have recently been using the below design and so far it seems very promising.





This is just the first prototype and for this, I used a 1/5 scale RC car CV joint (This is from a FG Marder) its just case hardened steel that I cut in half and drilled to take a 1/8 piano wire shaft. the balls are normal ball bearings and due to the specific tolerances once they are pushed in are able to rotate inside the bore without falling out.

The cup is silver steel, this was a prototype but I have since machined a hex on the outside so that I can tighten them onto the crankshaft. they are also hardened and tempered. For reference, the main bore of the cup is 12.5mm and the ball bearings are 5mm, OD is 18mm

At the other end of the shaft, I made my own cup and skeg shaft - See below.





These are pictures of prototypes again but are useful for an explanation. The ID of this smaller cup is 6mm and the balls used are 2.5mm, literally half the size of the other end. Again, once machined the cup and skeg shaft are hardened and tempered.

I have used this on a .60 Picco speed powered hydro with no issues at all so far though I am still trying to perfect the tolerance for the ball fits on the smaller shaft.

By design, this is a very balanced set up with very little slop/play compared to the more usual single pin through a ball design that is typically used.

Regards

Ricky

 

[Terry Keeley]

Very interesting, I never saw a connector like that before.

Can I ask what coupling(s) you were running? Where did they fail?

What part of the world are you in that still runs tether boats?

 

[Ricky Neal]

Very interesting, I never saw a connector like that before.

Can I ask what coupling(s) you were running? Where did they fail?

What part of the world are you in that still runs tether boats?

The couplings we use in tether hydro’s are normally all bespoke home made designs but are very similar to what you have shown above. They often fail at the in that goes through the ball much like yours did. We have also had some of the cups fail as well.

I am based in the UK, we still run competitive tethered hydro’s. We often compete in Eastern Europe countries as they are also still running tethered hydro’s and very competitively as well.

The euros/worlds is mostly held in Bulgaria now but we have competitors from all over the world.

We utilise some interesting props and engines. Here are some pictures for reference.

 

[RaceMechaniX]

Welcome to IW Ricky, those are some very nice looking tether boats. Do you have an online gallery with more pics or a page within onthewire.co.uk?

 

[Terry Keeley]

Very interesting, especially since it looks like you make most of your own stuff.

Do you make your own props too?

What fuel do you run?