Thundercat 31 conversion build

[Doby]

Simple piece of aluminum bent and mounted to the existing framework has held up well for the past 2 years.

[Bullwink]

I got a Williams Racing Products 5 Inch motor mount from Jim at South River RC Boats. It is aluminum, fits perfectly and attaches to the stringers inside. I have opted to save this mount for a Skunkworks Cat build I am doing. but as I said, it will fit perfect in the Thundercat. http://southriverrcboats.com/shop/ca...aram=cid%3D%26.

In the pictures I posted above, I just epoxied in a motor mount from OSE.

[phazewun]

Great find !! thanks

Also what do you think the best KV rating / ESC combo would be best for this ? im looking for 45-50mph on the water running 4 or 6 cell.


And advice as to what the COG should be installing the motor mount,

[Doby]

http://www.youtube.com/watch?v=0WHYeVcmuLw&feature=player_embedded

Heres a vid of mine....shes a good solid 50mph in the right conditions, but in the rough stuff, it suffers a lot. Still, a fun boat in the right conditions.

[phazewun]

thanks !!

[Bullwink]

You (Doby) set up your boats very nice. I have seen some of your other videos as well. I live in Phoenix so we have the "right conditions" most of the year. 70 degrees today!

Phazewun: My setup is the Tacon 3674 1300KV supposedly handles 12S 44 volts. (Not that I would try that in this Thundercat!) I am running it in my Shockwave 36 FE Conversion with a 200 AMP Swordfish, & X447 prop. I have run it on 6S with cool temps all the way around. I could probably prop up but it is barely controllable now. While a Castle/NEU motor is usually the best, the Tacon LBP3674-B/5D-1300KV is only $39.99 now at Hobbypartz.com. I hacve a Swordfish 240 amp HV ESC going in the Thundercat. While you probably do not need anywhere near this big of an ESC, my thought is over compensating on the ESC saves me money when I start to do stupid stuff like overpropping, etc. Once I have this build done and set up right, I will probably try my Castle/NEU 1515 1Y 2200 KV motor for comparison.

[phazewun]

So what if i did this motor

http://www.hobbypartz.com/ta7090bomo.html

with 180a ESC on 2x2s 5000mah 30c

i could expect 50ish ?

or should i look into the turnigy instead, im trying to keep the cost down cause i this boat will sit @ the lake house so i dont need to dump a bunch of money into it.

[Bullwink]

Yes, this is the exact motor I bought for it and for the same reason - cost, plus it is my first build. I am expecting 50+ on either 4S or 6S. We shall see........
The 180a ESC should be fine depending on the prop. I will defer to other more experienced boaters on what they think of this setup. Also, I am taking others advice on this forum and starting with smaller props, check temps, and then propping up.

My Hifei Swordfish USB went bad so I ordered another one today to program the ESC. I am planning on hvaing it in the water in the next 10 days or so.

[Bullwink]

Here are my latest pics. Speedmaster Strut installed. I had to put a 7/16" brass tube on fromn the stuffing tube to the strut. Top Secret Rudder. Tacon motor with cooling jacket installed.IMG_0766.jpgIMG_0768.jpgIMG_0769.jpgIMG_0770.jpg

[Doby]

A 1300 kv motor on 4S will not get you to 50mph....the Thundercat is a porky hull with a lot of wetted surface...look for something in the 1800-1900 kv range....one of the larger Leopards should work.

[phazewun]

Heading to the lake this weekend last shot @ nitro before i rip it apart.

something doesnt look like right now, im thinking i need to remove that flex cable and reset it ? Seems like there is a large gap between the prop and the flexshaft holder.


20111228_163726 by phazewunfx, on Flickr


20111228_163734 by phazewunfx, on Flickr

[Bullwink]

Doby, I made a sub hatch for this. Question: Did you attempt to waterproof the regular hatch by covering the Air Scoops and the two holes in back? Also, did you eliminate the Exhaust port on the Transom or did you plug it?

Just curious.

[Doby]

Hi Bull;
Its pretty much impossible to waterproof the main hatch, as long as the subhatch is taped well, all should be good. I siliconed the exhaust opening closed.

[Doby]

ThunderCat 011.jpgThunderCat 012.jpgThunderCat 013.jpgThunderCat 014.jpgThunderCat 015.jpgSome Pics;

[Doby]

ThunderCat 016.jpgThunderCat 017.jpgSome More;;