6s OBT motor feeler thread

[David Kingston]

Boys a video of the boat running for you to view.



Not the best quality as it was taken from my i-phone but it gives an example of the speed and stabilty.

Again setup is 1527/1y - x448 prop - MGM250 amp ESC.

Not pushing hard on any equipment and its nice and stable.

The oval here is about a 70m straight. I did 8 laps of that. 50% left in the packs and only just getting warm. Would easily make the distance.

I do need some slight trim work.

I have a 1521/1.5y to test also.

Just need to get out to the dam more often.

Dave

 

[Bill Britton]

Looks like it's time to whoop up on some 40's to me!

/B

 

[RodneyPierce]

David, that boat is flying! Looks incredibly stable too! i would say you have a winner there. very nice.

 

[David Kingston]

Thanks guys.

This is my new favourite boat. Just a blast to drive.

I love the throttle curve on the MGM. It can take off nice and easy on the video or i can nail it and it will back flip.

I have also replaced the teflon liner in the lower also. The video shown was the 3rd run of the day. On the 4th run i made a meal out of the flex. Both ends were mashed up. Its now got nice brass liner in it which support the cable right until it enters the stub shaft and on the other end the motor coupler.

Dave

 

[HTV Boats]

Looks very nice David and I totally understand how it becomes your favorite boat. The Vision 40 is a natural for FE. 1520's on 6s are capable of mid 60's heat raceable and into the 70's SAW. What ma packs are you using? How many ma's are you putting back in after 8 laps?

Mic

 

[Doug Smock]

Nice work sir!! B)

 

[David Kingston]

Mic,

Late reply but i have been busy and finally got round to testing a few more things.

The 8 laps with the 1527/1y i pull 50% out of the pack.

I have now installed a shaft oiler and have not had any issues with the flex cable. I did some adjustments on motor coupler and made sure that the flex was not binding or being squashed when under load. seams to have worked the treat.

Today i managed to put a few more laps on it.

Changed the motor to a 1521/1.5y - 1050kv. WORKS A TREAT on 6s with the same prop as the 1527/1y. (x448)

temps were a tad cooler on the ESC. Motor and cells were the same. Still not pushing then hard at all. Speed was about the same, maybe a bit slower. I did have a bouncing issue and i put that down to the change of weight on the back due to the lighter motor. Slight adjustment on the COG with the cells and that seamed to work - for now. (more testing and props to run)

Ive got some new props on the way that i plan to run. Very keen to start to tinker with props now and start pushing the boat harder. The 1521/1.5y works a treat and after about 8-10 laps of same size oval posted above (different location) i was only puling 50-52% out of the pack. Wish that i was counting laps. Water conditions were less than perfect for testing but the boat was still able to pull 100% throttle into the wind without wanting to blow over.

I will post a video up when i sort out my prop for the job and dial it in a bit more.

Does any one know and would like to list some props (stock or mod) that that know work well on 40 tunnels. Just want to see what else might be work a try

Dave

 

[HTV Boats]

David,

Sounds like your doing well with your setup. It is interesting your battery draw at 50% of a 5800ma pack. Guess the low kv's in relationship to a 448 are working. Speed aside thats really good. In heat racing a 5300ma 5S setup with a 1600kv motor after completing a heat with a m445 we use at least 80% leaving 20%. Going up to a m447 it only made 5 3/4 laps. Speeds are into the high 50's. Next we will try 6S 5000ma which should give a little more power. May need to prop down also. I guess thats going to be the key to racing here. How much speed can you get out of a limited battery. 5-6000 ma is about what works in a tunnel with limited space and any more may be just carrying extra weight that uses the extra power. Kind of going to be its own form of restrictor ma racing for tunnels.

Mic

 

[David Kingston]

Well just bumping this thread again.

Ran the boat late April at Australian nationals. Got a win with it. Yippy!!!! Just consistency and finishing each race with a few heat wins does help. (only boat I raced that I didn't cut bouys with - that's how easy it is to drive)

Setup was

1521/1.5y

6s/1p

Prop 455 detung and cut to 452.

Only used 50% cell capacity in 1/2 mill 5 laps and 1 finish lap.

No water cooling to mgm250 Esc or motor.

I was racing inboard cats also, with big power pushing 40inch hulls. Kris Flynn had his obt going also which had some insane speed over mine. Shaft issues which I think he will have sorted soon stopped him short.

Just thought I'd share the setup as its fantastic for sport setup which can do about 8 laps easy and also has ability to race.

Dave

 

[topfuel443]

Any idea what kind of amperage you are pulling with the Kv/prop setup? Interested to try the lower KV/bigger prop on my 6S tunnel, but not sure if the T180 can handle it.

 

[David Kingston]

No idea what amps but it wouldn't be much.

With half mill and 6 laps I still had 50% or more in packs.

Cell temps 110degF

Esc - fan cooled - 120-130degF

Motor air cooled and it was cold.

Im not sure what motor kris Flynn ran but it was castle 1600kv or something with a 42mm prop I think. Did go harder than mine. He had a T180 in there and it was solid. I never had a T180 to test when I built this boat, but I'm super happy with the MGM. Throttle curve is fantastic and smooth.

Dave

 

[topfuel443]

Yeah, im running a M445 on 6S with a Leopard 4082 (1600kv) on a Vision and its ballistic... I have about 20% of a 5000mah pack left after a 6 lap/half mill lap race so far. Just looking at other alternatives. I would suspect the 180 could handle it.

~ James

 

[RonShaw]

Yeah, im running a M445 on 6S with a Leopard 4082 (1600kv) on a Vision and its ballistic... I have about 20% of a 5000mah pack left after a 6 lap/half mill lap race so far. Just looking at other alternatives. I would suspect the 180 could handle it.

~ James

Hey,Glad to hear you have your second Vision Q running. What speeds are you getting, any ideas? Its impressive that you only need one pack. Maybe you can get someone to put it on the radar. My thoughts were it needed to be in the 65+ mph range for a strong heat racing boat.

 

[Kris Flynn]

I am using a T180 with 2 extra capacitors on it (5 total)

CC 1520 1600Kv

Turnigy 5000's 6S

42X55 prop (pretty sure stock)

Vision

Lawless 7.5 lower (modded)

Probably only running in the 50MPH range

the 1 race i finished i think i had 25% left...everything seemed luke warm to touch. with good batteries i am sure there would be more left in the packs and better speeds to be had. With the current setup (above) it makes it a great sport boat, as that is what it will be for 99% of it's life, unless FE becomes more popular, or those FE sooks from up north ever travel down south!!! (HAHAHA)

I kept killing flex shafts because i modified a lawless to get the motor down lower, then also filled up the cable groove with JB weld and re-machined a new groove. i stuffed this up by putting too sharp a radius in, the cable snapped in the same spot every time, after about the same amount of use! Typical with racing, i did not break any during the 3-4 test runs i had on the boat before the Nats!!!!!

I am going to be honest here and say that the Vision 40 seems to run alot lighter (maybe too light) on the water especially compared to the 20 boat, i would really like to try a few 'mods' to create more downforce with it...

 

[topfuel443]

No idea how fast it is Ron, its faster than any other tunnel I have ever owned. More importantly, it turns and handles well. Speed (which seems to be easy with FE) is just an added bonus when you get one that will turn and handle in my opinion. It can be faster than the boat will handle, which will still make it a drivers race. Kinda the reason I like tunnels so much anyway, so Im ok with it for now. I will run another couple packs through it this weekend.

~ James

 

[RonShaw]

No idea how fast it is Ron, its faster than any other tunnel I have ever owned. More importantly, it turns and handles well. Speed (which seems to be easy with FE) is just an added bonus when you get one that will turn and handle in my opinion. It can be faster than the boat will handle, which will still make it a drivers race. Kinda the reason I like tunnels so much anyway, so Im ok with it for now. I will run another couple packs through it this weekend.

~ James

WOW. You sure got that one together fast!!! I like your thinking on the lower unit and Leopard motor choice. Looks like ole Mic is right again, but don't tell him I said that.... He has said all along that I was going to high in motor choice and should re-think my choices. After hearing you talk and seeing Jay run his in open, he is obviously all over it. If you can run 7 good laps on one pack, and still have that much capacity left over, you have nailed your setup. At the most you may need to go to two 3s 3300 packs in series for 6600mah total, (1600 mah cushion). If you get a chance to get someone to make a video of a couple of your runs, I would like to see them. Thanks for sharing.

 

[HTV Boats]

Looks like ole Mic is right again, but don't tell him I said that.... He has said all along that I was going to high in motor choice and should re-think my choices.

OK Ron hold that though. Second thought just keep running those ole Lee boats.

James,

Looks like you have upgraded your lower and surprisingly the OS with a .150 cable holds up well with Q motors. The only thing we noticed on smaller hulls like the Shaman we needed the .45 K&B lower for better handling.

As far as speeds I don't think our Q that Jay ran with the 1520/1600 Castle runs much over 60mph in heat race trim. It just gets there fast. The same setup last fall at Valdosta with a 1914 and X450 ran just over 70 mph but would blow over going into the wind using 3000ma's in two passes. I have run a 1250 Leopard on 6S which allows more prop (M447) and lasts 6 laps but the 1600 with a M545 is faster. I havent had the time to run bigger props with the lower KV's yet but will surely try. My though is smaller diameters will save batteries and be easier on ESC's. I cannot however ignore Dave's results either. Time will tell which way is better for heat racing. Boats and total weight may dictate the power requirements and thats why we need a few more people to race heats. We are all in our knowledge infancy here. Makes racing fun and challenging too.

Mic