Behind prop water pickup 4 Q-Sport hydro Questions

[ray schrauwen]

Even though I have to dial the Q-sport in more I am adding a second water pickup behind the prop.

I'd like some advice on this, maybe call Brian B. on the phone or PM him to see how he makes his.

I don't know how much of a radius I should do and how strong it needs to be? I have some thick wall K&S brass with 1/8 ID which is the ID of the esc tubes etc but, it's thicker and going to be harder to bend.
I've decided to mount the final curved end to the actual strut with 4-40 bolts threaded into the strut. I'll solder a bent piece of 1/16" flat brass to the tube for the bolt to hold onto and have the tube come from the top if that's a good idea.

I'd like to know what proximity the end of the pickup should be in relation to the prop, distance from prop etc...

I did modify the SF200 8S esc with a second water cooled heat sink on top and programmed it to 10* timing for Y wind instead of all auto like I used at Elk's Lodge. I need the SF240 for my big mono.
I think some heat is coming from the stuffing tube and as soon as that's out I'll know how to cut down on some friction. A combination of not the correct timing on esc, too big of props, rushing and a few other things contribute to the 'hot' setup I was running. I'll switch out the TFL coupler for an H&M too just in case. I've got a longer motor cooler too now that Steve carries them. Almost forgot, I also received a few cap banks today to add to the SF200 as it was just stock. Got that puppy up to 175F and it's still o.k. on the bench so, cross my fingers

All advice appreciated. Thx!

[ray schrauwen]

Just found one heat generator, the motor was taking all thrust on the rear bearing. Need thrust bearing at motor or strut. Where to get this.....???

[RaceMechaniX]

Ray,

Although water blast pick-ups work OK, they are not as consistent as rudder pick-ups. You are better off Y'ing a single pick-up or getting a dual pick-up rudder.

If you are dead set on using a prop blast pick-up it should be a 180 Deg bend type, not the 90 Deg pointing straight down into the water type. Use 1/8 or 5/32" tubing. The trick to bending a smoother radius is to take a bunch of small diameter solder, twist it together and feed through the tube so it takes up most of the space. It does not need to be tight. Dip the solder in oil or WD40 if it wants to stick inserting into the pipe. Then find a circular object with the correct radius to bend around. Pull the solder out after the tube is bent. Make sure to deburr the incoming edge and/or just a body reamer to add a slight chamfer on the inside.

The water pick-up for a CCW prop should be on the right side of the centerline and up about 3/4" of the prop radius. You want the pick-up to collect water as the prop exits the water.

The pics below show the pick-up too far back (intentional for a SAW rigger) from the prop, but the height is correct.

TG

828731871_dsc00252.jpgP1010037.jpg

[T.S.Davis]

The trick to bending tube is to tape the ends and fill the tube with sugar. No kinks ever. Dump it and rinse with water.

[ray schrauwen]

Cool, thank Tyler and Terry.

I found a major heat source, almost wore through the stuffing tube in 4th heat. After 3rd heat and hitting Bob, the stuffing tube got crushed and was bound like crazy, can't even get the cable in ! OMG., I'm surprised the motor still works, hopefully. I can only imagine the speed I'll pick up because it looked slowest in the 4th heat.

I think I'll try a Y. Do I use 2 water exits or rejoin them??

[ray schrauwen]

That first picture is awesome. the rooster coming off the bottom blade like that and a tight cone, nice.

[T.S.Davis]

Ack....double post.

[jcald2000]

Ray, a Y fitting will flow the majority of the water to the side with the least resistance, not a good option.
The prop pick ups are very inconsistence because water off the prop changes with going over waves, with the lean of the hydro- they do lean and the depth of the prop. I could not find consistence setup.

Dual water pick up rudder is what I use now with no problems.

[properchopper]

Ray, I agree that a "Y" will favor the path of least resistance. I'm using propwash pickups for my second cooling on my spec motors. This easy-to-make pickup on my FE30 developed enough pressure to blow the line off the bulkhead fitting (which to be fair had some internal corrosion) and shot the water stream up a good 6"-8" during a heat. I was advised by my pit-man (one Mr. Tyler G.) to bring it in to preserve the now uncooled motor but I motored on wanting to finish the heat. The smell is almost gone from inside the hull as of now.

DSC06007.jpg

Same setup on the Snotley Screw

DSC06011.jpg

[ray schrauwen]

Thanks guys. X-Ney on the Y-Ney splitter then. I'll rig up a prop wash pickup.

[Fluid]

Why do you think you need additional cooling? KISS and run one to the ESC then to the motor. Very little heat is removed from the ESC, it has little mass compared to the motor.


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