twin super cat

[Jesse J]

Since our club is chill enough and nobody comes out with a tape measure, I will take advantage of the 1/4" courtesy margin on boat lengths... I've measured three times and can't get her under 34.25".
this will be for P offshore

I have been wanting to get my Proboat motor back in a cat ever since my Intruder 3 years ago. so this will be 4S per motor and w/in the 10000 mah limit.
Got the hull from Elijah, who has been asking me to post progress. She showed up Saturday afternoon and she is ready for her maiden voyage.

First thing was to fill the front with 2part foam (2lb is fine and boat is still light but very strong).

I am fabbing up a fiberglass reinforced hatch with my own custom cowl - getting final coats of epoxy this morning.

I was going to go wire drives, but someone had a little too much wine when gluing in the motor mounts so one was too tight of a bend... I had flex cables on hand so no downtime. Gonna use AQ struts - cheep, relatively scale and easy to adjust.

IMG_1448.jpgIMG_1451.jpgIMG_1454.jpgIMG_1456.jpgIMG_1458.jpg

[Jesse J]

got drives encased in epoxy and supported at motors with flap of heavy fiberglass.

On these motors, I have always been disturbed by thin wires... so I have added some wire filler to the bullets.
just jam some in there and trim off after soldering.

[Fluid]

Lookin' good Jesse, what props will you try? I assume this is a P-Offshore racer since P-Limited is restricted to a single motor. Keep the following in mind:

c) There are two acceptable multi-motor configurations for the Power Specifications that allow multiple motors:

i) Each motor must see a nominal voltage within the Power Specification. The mAh capacity maximum within the same Power
Specification is for all motors combined.

ii) The sum of the nominal voltages powering each motor must be within the Power Specification. The mAh capacity maximum within the
same Power Specification is for each motor.


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[Jesse J]

Thanks for the clarification Jay. We Willemstad see how she does with these motors ... May upgrade with 2200kv leos.
Props are either 42 or cut down 47s.

[Fluid]

If those are ProBoat 1500s don't bother with 42s. They can swing full 47s and maybe larger. The 1800s will be happier with smaller props.

Willemstad?



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[Jesse J]

Ya you know Willemstad ? It's in the Italian autocorrect dictionary!?! Silly me. If you find out, tell me what it means.

Good point on props; I'll use the 42s when I try 6s for kicks. The 47s should be fun on 4s too.

[jevmax]

Looking forward to seeing this cat run. I had one like it with twin Hacker B50-9XL motors a few years ago. Should've kept it.

[Jesse J]

got her done, well except for water cooling... I jimirigged some propwash pick ups, but I never saw water coming out and one even fell off... Even without water cooling, motor only got up to 150 after a couple laps. Thinking maybe thru hull pick ups or getting me a dual pick up rudder that is a little longer.

Here is video of maiden voyage. Looks like the flat strut angle and COG about 32% worked out about right. These are my cut down 47mm props. I am now curious what will happen when this hull is pushed a bit harder!

[Jesse J]

rhino horn be gone

I couldn't take the rhino horn, so I surgically removed it. Wasn't too bad, foam had filled it in so all I had to do was cut through the gel with the dremel then cut the foam with the hand saw. I painted on thinned epoxy, laid the glass then this morning trimmed her up. now to fill with more epoxy or bondo and get the paint goin.

[Fluid]

I really like the looks of the modded deck. I had several M-1s and loved the way they ran, the looks were just 'okay".

Interestingly, the M-1 has an identical bottom to the Drifter. However, they handled differently. This was confirmed when two club members built one Drifter S and one SuperCat S with the same power and hardware. The M-1 always cornered at a higher speed. We figured that it must have been due to the deck/hatch configuration. It will be interesting to see how yours runs.


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[Jesse J]

Thanks Jay, I am psyched about how it came out. Can't wait to get her painted up.
Do you think a pair of 1415 1.5Ds would be a good option? That is the motor that was in the titan I got from you, yes?
How did you like the handling of the video?

[expresscraft]

on a cat hull, the center is a wing,that's why a lot of times on a copy of someones bottom, if the guy doing the coping or the guy making the boat for that matter does not understand this ,there boat will not run well, they are not just two parts put together, although that will float,lol.Its that top and bottom of the wing that makes a cat fly.

[Fluid]

I agree Tom - I've designed more than a few successful cats in my time. Both of the H&M cats used the same mold for the hull bottom, and they both performed similarly at top speed in the straights. It was in the turns where they were differentiated, where much of the air compression is lost. We assumed it was differing sideways airflow across the deck which caused the Drifter to roll over while the SuperCat stayed upright.

Jesse, I had the Neu 1512/2.5Y with a Kv of 2500. The 1415s are a bit smaller in diameter but I think a bit longer. Too high a Kv and you'll be limited in prop diameter, I'd not go over 2200 for a 4S application.


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[madmikepags]

Express you're right, just like the Sprintcat.40 and the team believer they have the same hull bottom but different decks, and the sprintcat corneres much better than the TB!! I always loved the M1 I had 2 of them, one was with a 1527/1D on 6S!!! it went like stink the last gps reading was at 88mph before it launched 12-14ft in the air off a nice little ripple and split the hull on re-entry, must have hit hard because these hulls are built well. The other was a P-OFF setup 1521/1.5D and it ran really well, when I switched to the Sprintcats 4-5 years ago I stopped running it and sold it. This thread has gotten me interested again, and I'm picking one up on thurs!!!!!!! it will be a P-off setup again 1521/1.5D cant wait!!!!! Good luck with your twin!!!

[Jesse J]

So now I'm glad I did a run before I cut the horn. That said, the horn was a small part of the hatch, which is long and high.

Is the drifter low profile like I am turning this one into?

I'm curious to run her now without the horn and see if I made it handle worse...