Time to completely re do the Widowmaker!!

[JackBlack26]

Hey guys. This is my first time attempting to do this much on a boat. Implementing most of what I have learned here. Any input would be greatly appreciated. I will update this thread as I go along.

I got this boat for $90 from Hobbymart on Ebay. It had a burnt ESC and the motor went shortly after a few runs. I love the size and build of the hull but the placement of the electronics is horrible:thumbsdown:. The motor sits too high up and too far forward. I believe that's the reason why it porpoises the way it does, which is everyone main complaint with this one. I didn't want to sell the boat so I figured I would try and put the motor where I think it needs to be, around 27%. It used to sit at over 50%! I don't know yet if the battery will sit just above the motor coupling in a tray I layed out of fiberglass or if I will run 2, 2200 2S LiPos like pictured, for a total of 4400mah in parallel, to keep the COG as low as possible. The servo will lay on the hull and the ESC to the opposite side of the servo.

Here is a video of how the boat ran before with the stock motor. Wasn't too bad in a straight line but I don't think the boat was engineered to turn while on power. It was like running a slalom course in an F350 with a 8" lift:doh: http://www.youtube.com/watch?v=l0kbUc4gHWM

You can see everything was very high centered. It was ridiculous how far up and forward the motor was placed
http://i157.photobucket.com/albums/t72/rlopez75/DSC00990.jpg

I layed 2 layers of glass underneath the motor mount then glassed over the mount, held just at the right angle, and let her dry over night. I used some 43mmx3mm o-rings to fit the Pro Boat cooling ring around the 36mm 6XL motor. The XL motor is a beast in this thing but it's just in there for now. I think I will end up going with an Ammo 36x50-3300kv since this is a 2S configured boat.
http://i157.photobucket.com/albums/t72/rlopez75/DSC00991.jpg

You can see in this picture how much I moved the motor. That's the stock cable
http://i157.photobucket.com/albums/t72/rlopez75/DSC00993.jpg

This might end up being the final layout with the batteries in parallel.
http://i157.photobucket.com/albums/t72/rlopez75/DSC00994.jpg

[SweetZ28]

Hi I don't think it will do any good the hull shap i feel is what kills it... but you never know see how she goes!

Mine has trim tabs it don't hop to much but it can't turn for crap I think again it's the hull it's to shallow and has no v shap to it.

[JackBlack26]

Thanks for the input. The hull is kind of weird the way it goes from a v shape in the front to almost flat in the back.

I don't know if this will help at all, but lowering the COG of everything inside the boat and moving the motor to where it should be cant hurt ether......I hope!!:bowdown:

I decided to do this because it's really not costing me anything but time and I figured it could be a good learning experience for me.

Thanks again for the reply!:thumbup1:

[SweetZ28]

I know the hull is wierd ... hope this works for you And i hope Proboat did not put the motor so far up for a reasion with this funky hull shape you never know!

[Chuck E Cheese]

keep in mind that this is a steped hull. the cog is not going to be the same as non-steped hulls, it is usually further forward. also the key to getting these boats to work is the angle of the strut. one of the guys at my pond had one and it actually ran pretty good, just a little hop in the turns. it was on a detounged/bar cut 535-3 prop and that made the difference. there is probablly some info on it in the forums (iratner user name, search the rtr widowmaker threads).

good luck as i have never liked or had any luck with steped hulls except the mogli

[JackBlack26]

Thanks again for thebinput. I know there is probably a reason why the motor was so far forward but I don't see why it was so high up. In the video you can see I got it to where it did not hop too badly but I just wanted to play with the boat layout and see if I could make some good changes. If it doesn't work I'll put the motor back where it was, but on the hull not in the air. Should have it done by this weekend. We'll see how it does.

[SweetZ28]

Lucky you in NJ all ponds are ffrozen!!:ohmy:

[SweetZ28]

:popcorn2: Any updates?

[JackBlack26]

Yeah, we are pretty lucky to have reasonable weather year round.

I need to make servo mount for it and possible get a longer pushrod for the rudder. Probably won't hit the water until Sunday. I'll take video though and report my findings.

[SweetZ28]

:popcorn2: Cool i will be waiting for the video and update!:popcorn2:

[Make-a-Wake]

Nice project, one bit of input is that you should get better batteries. 20c in a boat is really not sufficient............especially with high kv motors like you are considering. I'd get 30c 3000mah minimum for running 2 x 2s in parallel. Your 2200 batts can only provide 44 amps each, and though in parallel, they will most likely get hot and possibly puff.

Looking forward to seeing it run!

[JackBlack26]

Yeah, I thought about that after I posted that picture. I was sitting in the garage looking at the best way to configure a single pack in there. I really have no use for those tiny packs but I don't want to take a chance at burning up the boat considering how inefficient the purple HK motor is. I think I'll just mount the single pack in the tray I made, just about where the stock battery location would be. Hopefully it doesn't affect handling too much with it sitting just above the motor coupling.

Thanks for the input!

[SweetZ28]

What you can do is hook them up together so they would be one big pack 4400 20 C then it should be able to handel it i think.

[JackBlack26]

SweetZ, that is what I originally wanted to do. But at 4200x20C=88 amps. I may try it like that once I get the 6pole Ammo 3300kv motor. But I don't know if I would be brave enough to try that with the cheap Hobby King purple XL motor. Those things draw a lot of power due to their low efficiency.

I bought some flat stock aluminum today, from which I plan to make the servo mount with. I'm going to get on that tomorrow night and get the boat back together and in the water, hopefully Sunday, but for sure on Monday.

If all goes well when it hits the water I plan to paint the boat white and the gray star sticker on the front of the boat will be painted on, red. Instead of the "Military" theme it has now, I plan to do more of a Search and Rescue type of theme with those colors. That should make it easier to see in the water!

[SweetZ28]

Cool.. I thought you where using the stock 2900KV motor in it.

[JackBlack26]

The epoxy came loose on that motor and the windings came loose. They started to drag on the rotor an it killed the motor. The stock motor isn't any more efficient than the HK motor anyways. They are both cheap 2 pole motors. The insides of both motors are almost identical. Same ratty looking windings in both, with probably a 60% efficiency rating, if that! It will be nice to get a good quality 4 or 6 pole motor soon.

[JackBlack26]

Ok. No video today but I got a chance to get it wet. The boat is a completely different animal. Since more of the weight is shifted towards the rear it's on plane almost instantly after hitting the throttle. Gone is the "sway" when turning. No longer does it turn like a lifted F350! Its 100% more plated than before and it runs less wet than before. Conclusion? Success!!

I got a lot of negative remarks about my project mostly from people who had given up of stepped hulls. After researching lots of forums and reading a bit on the web on stepped hulls and hydrodynamics I came to realize that the spot where I put the motor is where boat designers who work with stepped hulls concluded that the CoG is on a stepped hull boat. That spot,"typically", is one step above the lowest part of the boat. In this case Proboat put it too high and over the first step of the hull. It's in the wrong spot according to what I have read and by the experience I have gained from rebuilding this boat.

The picure below is of the final layout which worked for me. Placing the motor on the hull lowered the CoG and placing most of the weight over the second step of the hull put most of the weight in the boat right where it needs to be. I'm happy with the outcome!!

The motor will be replaced with a B36-56-2600KV motor and a Turnigy 60A marine ESC that I ordered today. :buttrock:
http://i157.photobucket.com/albums/t72/rlopez75/DSC01003.jpg

[Make-a-Wake]

Great news on the result! One thing i need to point out to you though...............You will most likely fry the 60a ESC on the first run with a 36-56 2600kv motor..............get a Turnigy 120 for 49 bucks.

[JackBlack26]

Really?

The boat weighs next to nothing and is only 22" long. It comes stock with a 36-56-2900kv motor and a 45A ESC from Pro Boat. I figured running lower KV and higher amp rated ESC might cover it. I have read of people running a Turnigy 35A ESC with the stock 2 pole 2900kv motor with luck.

We'll see how long it lasts when it gets here.:sinking-guy:

:beerchug:

[Make-a-Wake]

Well............i did happen to forget it was a small boat, with a smallish prop it may work out....................sure hope it does! Its just that a 36-56 2600 can pull some big amps. Lets see some vid!

[JackBlack26]

It has been raining here all day so I didn't get a chance to get to the pond long enough to take video. I'll try and get some video soon.

The 2600 is going in there with the stock prop which is pretty small. The boat will end up being my 9yo son's since he wants to get in to boating now. If the cheap HK motor pulls too much, and he likes it, I'll break down a get an Ammo 36-50-2300 and prop it up a bit if necessary. A 6 pole motor should be far better suited for the 60A ESC considering efficiency, no?

[SweetZ28]

Looks good hope can't wait for the video!! I may rip mine apart if it works way better now!:smile: