Sprintcat runs

[Bookwood]

Hi
I am Norbert from Germany and have been driving electrically for 5 years.
By now I have gained enough knowledge and here is the result.
Sprintcat 36 with Leopard engine 8072 500 kv at 12s.
Esc is a Dlux 250 watercooled.
Maximum speed was 89.1 miles with ABC 3018 so far.
CG and setup are still being changed as power consumption is still too high.

greetings

[Bookwood]

Yotube Video in low quality
better quality next week.

https://www.youtube.com/watch?v=zIgoW7E-hjo&feature=youtu.be

[Mike W]

Cool sound!

[Bookwood]

That's big engine sound.
The engine is self-wound, according to an internet manual.
I first practiced on a Turnigy T600 and on a Scorpion 5035, both are running great.
The Leo was already a challenge, because he has a thick wire.
But I love challenges, that's what makes our hobby.
IMG_20190720_151023.jpg
IMG_20190720_151436.jpg

[properchopper]

Hi Norbert

Boat looks nicely balanced at full throttle. These hulls do seem to run wet so loosening them up sets them free to go faster with less strain on the electrics.

I notice that you have a fan on the front of the motor. I've tried this on my Ltd. boats - both blowing "on" the motor or extracting air/heat from the motor. I never really measured the results in an empirically valid way. Have you seen how your fan helps ?

[Bookwood]

My engine produces a lot of heat even when idling.
At load after the run rotor and winding had 60 - 65 ° C.
That was at currents of 150-200 amps and small props.
After the runs, I always put this fan in front of the engine and the cooling effect was good.
Then I mounted the fan because I wanted to drive larger props.
I think that the aluminum cooling plate plus fan during the ride and after the run are sufficient.
With the 3018 I had over 300 amps.
Fan and water pump are running at the same time.
It also helps against heat accumulation until the boat is opened.
After opening the boat I measure about 55 ° C.

[srislash]

Wow, looks good. I’ve got to get on this real low KV thing. I’ve been doing small props and 12s @ 1000kv.

[Bookwood]

Low KV rate must also match the boat.
In the Sprintcat was always the idea to drive the same props, as the gas engine.
I also drive a HPR 135 with 880kv to 12s, which works very well.
Single engine, I think low kv is not bad.

[MarkF]

Hi Norbert

I remember some of your fast cats and crashes too:)
How did you water cool the esc? Does the motor get to hot with no cooling?

[dasboata]

do I dare to say that is not a sprint cat and a 3018 is a monster of a prop more for a inline then a electric ? although it does run nice and fast !!!

[Bookwood]

Remove the aluminum housing of the Dlux and mount aluminum cooling profiles from TFL Hobby.
I fix with Kaptontape, then heat shrink tubing.

http://www.hydroworld.de/vb/attachment.php?attachmentid=30958&d=1443792079

Since the Dlux is a flight controller and does not like water at all, I sealed the open ends with polymer glue after shrinking.
It's not pretty, but water always finds its way to electronics.
A good German forum is dedicated to 65 pages with the conversion of the Dlux 250

http://www.hydroworld.de/vb/showthread.php?10110-Reglerumbau-aus-Turnigy-dlux-250-HV-entsteht-ein-Jackodlux-14-250-HV

Whether the engine gets much hotter, I can not tell you, I've mounted the fan after the first day of driving to minimize the risk.

[Bookwood]

The boat was an Ebay fund for 23 € and was without cover.
I think somebody has changed that way to this form. The hull is 36 inches. Whether the boat is the same, I do not know, because I have no comparison.
The prop is so big because the engine is so big.
I hope it gets faster.

[Fluid]

The Sprintcat 36 was never designed for a gas engine, but rather for high revving .40-.80 nitro motors. A few have tried gas engines in them but most considered it a stunt. The OP’s approach is very interesting and appears to work well. I converted my SC36 from a Q racer to a sport boat with a Scorpion 4025/1100 Kv motor on 6S1P (similar rpm to the OP’s cat). With a modded x460/3 it runs upper 50s. Loaded rpm is 22,000 at ~120 amps. Not screaming fast but still a lot of fun. FWIW I use a computer fan on the motor too.

[MarkF]

I see that motor is low KV. Did you rewind to get 500 kv? I think abc 2923 might give good speed:)
I was running TP 5870 680 kv on 10s in my mono and burned up several esc. Swordfish and flier both didn't like the 6 pole motor. Does the new dlux handle higher pole motors better?

Mark

[Bookwood]

The Leopard 8072 has 14 poles, which works well with the Dlux 250. Timing is auto. Engine was used for 100 €, had 160 kv.
After several test windings with thin wire until I had the desired 500 kv.
In Germany, many drive the Dlux.
Many were destroyed because of flooding, few because of poor quality.
Peak currents of 500 amperes and more have already been measured.
Temperature shutdown works, you can see in the video at the end.
IMG_20181018_173904.jpgIMG_20190720_151436.jpgIMG_20181115_160533.jpgIMG_20190720_151023.jpg
Winding is DD 1.8 mm 7 turns.
That is, two separate motors are wound on a stator with the motor shafts running in parallel.

http://www.powerditto.de/schemamodus12N_DD.html