My Proboat Blackjack 24 project progress

[fweasel]

I recently got back into the RC boat hobby after discovering how far things had progressed with lipo batteries and brushless motors. I bought a couple of UDI RC boats for the kids off Amazon, and am cutting my teeth on a Blackjack 24 I picked up on craigslist. Between the first few runs and a lot of threads I've read online, the typical Proboat shortcomings have played out and I'm taking care of them with aftermarket parts as needed.
armada.jpg

Shortly after the first run, I drilled out the cooling pick-up on the rear rudder. Next trip to the pond, there was a noticeable improvement in output from the side of the hull. I think I'll eventually install an additional pick-up on the bottom of the hull and cool the ESC and motor separately. I also shimmed the rudder push rod at the servo horn with a home made plastic washer and a little super glue. That firmed things up and took a fair amount of slop out of the rudder. I had used a collar style attachment on my old nitro tunnel hull rudder, but my box of spare parts are long gone so I worked with what I had.
cooling pick-up.jpgservo shim.jpg

When I got home after the second time out with the boat, I pulled the flex shaft to grease things up. Figured I was staying ahead of the game. Nope. Next trip out, lost the flex shaft and prop 10 seconds into the run. I ordered two new stock flex shafts (didn't know about the upgraded options yet) and a PRB282006 1.6"x2.5" stainless prop from Proboat. The new prop gave the boat a little extra speed and the motor and battery only appeared slightly warmer to the touch after a full run.

[fweasel]

When I tore things down after the next outing, I noticed increased slop in the drive line at the strut. It always seemed crazy that there was never any type of bearing or even a bushing back there and that this kind of wear was inevitable. That's when I found Kintect Racing. I ordered a new strut and flex shaft from Kintec to fix the worn stuffing tube and ridiculous side to side slop.
stock flex.jpgstrut.jpg

I installed Kintec's motor mount and upgraded coupler so I don't lose another flex shaft at the bottom of the lake. Think I need to add a 9mm wrench to the tool box because the new coupler is slightly smaller than the original, which used 2 10mm wrenches. Still trying to get the old hatch screws out of the deck so I can install this set of spring loaded pins. Looks like I need to grind myself a custom tool to get the old ones out, or I might just drill them out with a dremel.
motor mount.jpg

Weather looks good this weekend so I'll take the kids out to the lake and test out the latest round of upgrades on the Blackjack. I'm sure I'll need to do a bit of tweaking to the prop/strut height. Hopefully the water is smooth and I can get a good sense of the trim angle. I also just picked up a used Shockwave 26 V3 on eBay. It's already got a HobbyKing 120A ESC. I'll drill out the cooling pick-up, grease the flex shaft, and run a 3S battery through it before I start modifying anything else.

[fweasel]

This weeks modifications were mostly Shockwave related. I installed the same Kintec Racing motor mount and coupler in the Shockwave that I put in the Blackjack. I have so much more confidence every time I tighten up the coupler. You can tell its going to hold the flex shaft and not crack into two pieces!
shock_motor.jpg

I also wasn't aware that the prop shaft should be trimmed level with the bottom of the sponsons on my Blackjack. After I installed the new strut, it was set-up pretty low. Now I'm about a 1/16" above the sponsons. Should be faster and hopefully run a whole lot cooler.
Before:
BJ_orig_trim.jpg

After:
BJ_trim.jpg

Speaking of faster and cooler... Great deals from Craigslist and Amazon on these two new additions to the tackle box
Forerunner201.jpgtemp_gun.jpg

Headed back out on Sunday to run with the kids. Wish I lived in the suburbs with a retention pond in my back yard that I could walk to in 30seconds. Downtown living is tough on this hobby and driving to useful bodies of water.

[fweasel]

Sunday was a good day at the pond. My son and I tried out a new spot I found online. It was a forest preserve pond (cricket creek, Villa Park) designated for RC boat usage, water was like glass. The Blackjack ran much drier after raising the strut, but has some bounce flat out in the straights. I brought it in after a few laps to check the temps and added a little negative trim to the prop. Motor and ESC were about 130*. The rest of the run was the same as the first and the trim adjustment didn't seem to change the bounce. No speed was recorded today, forgot the GPS at home. The previous weekend the boat run much flatter with no bounce, this was with the strut much lower. I have no data, but I assume it was a slower run with the prop running deeper in the water.
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[fweasel]

My family is out of town visiting family, so I headed out to the lake after work tonight. I did a little file work on the rudder trying to eliminate the flat bottom surface while my last battery was charging. I didn't get as much material removed as I had hoped, so I plan to take the rudder off and put it on the grinder later this week. I made no other set-up changes for today's runs, just trying to get some more temperature and speed data. Motor temps were 130-140* and the ESC was about 125*. I think I'm going to plumb a second water pick-up at the bottom of a sponson to cool the motor and ESC separately. Got the GPS installed today, but forgot to start it for the first battery. Second battery I remembered to start it and I got a max speed of 31.5mph in pretty ideal conditions. Aside from cooling, the only setup change I plan on making before my next run will be to finish the rudder reshape. I should get my stainless prop back from dasboata next week, interested to see if there's a bump in speed over the plastic version with the same size and pitch.
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[LuckY07]

Shortly after the first run, I drilled out the cooling pick-up on the rear rudder. Next trip to the pond, there was a noticeable improvement in output from the side of the hull. I think I'll eventually install an additional pick-up on the bottom of the hull and cool the ESC and motor separately.
cooling pick-up.jpg

When you say you drilled out the cooling pick-up on the rear rudder, did you drill a hole completely through the rudder (perpendicular)
or did you just open the hole up and make it larger?

Your pic almost makes it look like you drilled through the rudder.

[fweasel]

I found the drill bit the same size as the hole on the side of the rudder, then got the next larger bit and redrilled the hole to open it up. Drill in at the same angle as the original and don't go too deep or you'll drill through the back of the rudder.

[LuckY07]

I found the drill bit the same size as the hole on the side of the rudder, then got the next larger bit and redrilled the hole to open it up. Drill in at the same angle as the original and don't go too deep or you'll drill through the back of the rudder.

So you didn't actually drill through the rudder? Your pic looks like you can see through the hole.

[fweasel]

So you didn't actually drill through the rudder? Your pic looks like you can see through the hole.

No, you're just making the existing hole larger in diameter. I like to start with the smaller drill bit that fits inside all the way so you can realize what the proper angle is. Then I step up one bit, and drill in on the same angle. I either use a small rat tail file or the spinning bit to elongate the teardrop shaped scoop along the surface of the rudder. The drill bit usually does the job if you just apply some sideways pressure towards the rudder surface.

[kfxguy]

The gap you have in the last pic between the drive dog and strut is WAY to tight.

[LuckY07]

The gap you have in the last pic between the drive dog and strut is WAY to tight.

That's not my pic but I do have a question on that gap.

For the Voracity 36, I know the gap between the drive dog and strut should = the diameter of the flex shaft.

But my question is: Do I still need that Teflon washer between the drive dog and strut?

I plan on running the OSE HD flex shaft from now on in case that matters.

I assume the stock and OSE flex shaft is 1 piece?

[fweasel]

The gap you have in the last pic between the drive dog and strut is WAY to tight.

You're right, it wasn't adjusted properly there. I run with 1/8" gap between the dog and the strut bushing.

[LuckY07]

You're right, it wasn't adjusted properly there. I run with 1/8" gap between the dog and the strut bushing.

Why don't you use a teflon washer between the dog and strut along with the 1/8" gap? Doesn't the washer help?

[fweasel]

Why don't you use a teflon washer between the dog and strut along with the 1/8" gap? Doesn't the washer help?

On my boat, I've never seen any wear to indicate that the drive dog and bushing were making contact.