Leopard 4074

[Steve McGinley]

I just picked up a leopard 4074 and I am in the process of installing the motor. From what I have read this motor is pretty much a drop in without any modications needed to be performed. I bolted up the stock motor mount and fabricated a bracket for the front of the motor out of aluminum for the front of the motor to rest on. The question I have is when fitting the driveshaft I noticed the motor shaft is longer than the stock shaft which makes the tolerances very, very tight. No room at all for any lateral movement of the driveshaft. Do I need to cut the shaft down on the motor to make it shorter? I have the motor pushed as far forward as it will go and the driveshaft is sticking out of the strut a bit too far? Any help is greatly appreciated, thanks in advance!

[tlandauer]

I had the same issue when fitting a Leo 4082 into my MissGeico. The motor is pushed all the way forward and only half of the aluminum mount is sitting on the wooden platform. The Leopard shaft is 20 mm long---quite a bit longer than stock ProBoat motor. I would shorten the flex cable if the rest of the set up doesn't bother you. Why ? On subsequent purchases of Leopard motors I always ask Steven here @ OSE to shorten the motor shaft, but as I started to cut the flex cable more and more, I realized how much heat is generated while either cutting or grinding, it can not be good for the motor.
I have shortened quite a number of cables lately and never had a problem even it means I lose the soldered end ( collet end). I use Dremel with a cutting wheel and the windings never unraveled.
When you mention drive shaft, you mean the motor shaft or the stub shaft that is at the end of the strut? You need to leave a gap between the drive dog and the back of the strut--cable will shorten under load and you need to account for that. The gap is the diameter of the cable---usually the normal practice.
However, if you have no room between the collet and the stuffing tube, that is a different matter, maybe shortening the motor is the only way.

[stadiumyamaha]

I always cut the shaft of the leopard motors so that I will be able to install a thrust bearing without having to use multiple bushings. Jmo
A cutoff wheel cuts it clean and quick without much heat.

[Steve McGinley]

Actually the gap I'm talking about is between the drive dog and the strut. With the leopard motor I have about 3/16ths between the drivedog and the strut. With the stock motor about 1/16th and thats without the driveshaft and motor shaft touching. I have at a minimum 3/16 space because thats with the driveshaft and motor shaft touching eachother. I slide the collet on the motor shaft then slide the driveshaft in and it hits the motor shaft and I have that gap, thats with the motor mounted as far forward as it will go. I'm concerned about the gap and the fact that the motor shaft and driveshaft are touching eachother within the collet. I thought about cutting the motor shaft but I thought the same thing with the heat issue. I know heating metal can cause it to warp and with the precise machining of these motors should I be cautious of cutting that motor shaft? Ideally it would be best to cut the motor shaft because that way the collet woulnt be so close to the stuffing tube but that heat factor with the motor scares me! When you cut the driveshaft do you have to worry about it fraying?

[stadiumyamaha]

Yea the cable will be vulnerable to unwinding but all you have to do is re tin the end with solder. Then put a little chamfer on the end with the cut off wheel so it will easily slide in to the collet.
Either way will work. Although some time there isn't enough room between the collet and the end of the stuffing tube to leave the motor shaft long.

[tlandauer]

I only observed the heat from cutting the flex cable, the heat actually slightly melts the cable so it never frayed, the finished end is smooth and looked like there is a dab of solder. From this I concluded the heat is tremendous. But as stadiumyamaha said he never had an issue and i like to say that he is more experienced than I so it is your chioce. I don't think the heat would harm the motor shaft , it is the magnetic rotor that are epoxied then laminated on the shaft and the bearing I worry about. But then I generally worry these meaningless things. lol...
I personally would not worry if the cable touches the motor shaft inside the collet. As long as there is a gap between the drive dog and strut for the cable to shorten, you would be find. Look at it this way: even if they are not touching, the collet grabs the cable so tight that there is no movement needed inside the collet .
jmo, could be dead wrong...
p.s.
I am assuming when I asked to have the motor shaft shortened, the shaft was cut w/o taken out of the motor. Can't imagine the labor involved in having to take down the motor just to cut it .

[Steve McGinley]

Thanks guys, I guess its a toss up, I'll probably take the motor to work tommorrow and shorten the shaft.

[stadiumyamaha]

If it damages the motor then forget what I said and go the cable route. Lol
Really though, it should be fine.
Measure twice, cut once.

[d.a.v.e]

If it damages the motor then forget what I said and go the cable route. Lol
Really though, it should be fine.
Measure twice, cut once.

On a different note what kind of run times and speed are you getting out of your impluse with that 2200kv motor?

[stadiumyamaha]

I've gotten over fifty on 4s2p running a m545 and setting it up light but wasn't very stable. Normally I'll run two 4s 5300mah 4s parallel and a x442 prop. It will run mid forties for I think about 6-8 minutes but I've never timed it.
I ran it once on 5s and the crash was spectacular. Hit a ripple and helicopter'd it about three feet in the air. Its a great hull but doesn't like things over 50 and it likes to stuff too.
what kind of speeds are you getting? Set up?

[stadiumyamaha]

Keep in mind I'm also running a pretty big motor in it. Probably overkill.
The hull is tough as nails though, you can still see the chard area from when it blew up. Motor locked up and over amped the esc. The taped lid flew several feet in the air and it sounded like a shotgun going off. Hull was fine with only a bad stench after I cleaned it up and rebuilt it.

[d.a.v.e]

I've gotten over fifty on 4s2p running a m545 and setting it up light but wasn't very stable. Normally I'll run two 4s 5300mah 4s parallel and a x442 prop. It will run mid forties for I think about 6-8 minutes but I've never timed it.
I ran it once on 5s and the crash was spectacular. Hit a ripple and helicopter'd it about three feet in the air. Its a great hull but doesn't like things over 50 and it likes to stuff too.
what kind of speeds are you getting? Set up?

Because I wanted to race this boat I've been playing with the stock setup a bit & just got the gps going again but would guess my best speeds are around the mid 30's so far. Today I got 34mph with a 447x3 but only got 3 min of run time.

I've got enough batts for 5 runs so I'm thinking I'll go out soon and try 5 props (though they may not be set up great) to give me a feel for speed and which I want to play with more. Then I'm going to swap my motor to try one more recommended setup. If I can't keep up with the guys I'm wanting to run with I'm going to give up and try a new motor to play with this and buy the same boat rest of the guys are running.

[Stephavee]

I took mine out today and hit 54mph. Leopard 3674 1700kv. seaking 180, S/B M545 prop, 6s Zippy 5ooo mAh 3s-2p 45c. About 5-6 min run time. 35mph on 4s. love this boat! I also taped the motor openings and cut my motor shaft the heat was not an issue. speed taken with a garmin Etrex gps.http://i1138.photobucket.com/albums/n536/DangerDad828/P9220128_zps272ef3ec.jpg

[Stephavee]

Just a question...I know this boat was engineered to alow massive motors and batteries, but how big of a motor can this stock motor mount handle without rear support? It seems very beefy for a RTR boat but will it safely handle a 4074-4082 can motor? I would think the extra mass/length could play hell on most motor mount in a crash.