Fightercat Cheetah Twin Build Question

[Finest Racing]

Nice. To run in P Offshore, I need to be running 4s. I went out today using HobbyWing 180A on each motor. They went into overload. The red light was flashing when I opened her up. Everything was below 90 degrees. I am running TP 4070 2Y motors - 2200kv, with three blade 446 props. After about two minutes she will have this problem. The ESC are version 3 (V3). Strange how both are doing it. I plan on going back out tomorrow and trying again.

I am amazed how it is able to turn on a dime at full throttle like a slot car. I think I found the sweet spot for the batteries. This was my first time out with the ESC's. I hope I can get them to work. A twin drive I need to buy two of everything. LOL

When I figure the problem with the ESC's, I would like to play with props. Try a blade and three blades. What the heck, its only money. I can't take it with me. LOL

[kfxguy]

You are using the wrong props and it was probably running very wet. If both escs are going into protection I truly find it hard to believe they wer 90 degrees unless:

1) they were 90 degrees Celsius
Or
2) you waited a while to check the temps and your in a freezing cold climate.

Chances of having two defective units at one time are slim to none. Maybe you had it go into battery cutoff early. Try moving the cutoff to the lowest voltage selection and make sure it's on auto calculate cells. When you get tired of wasting time and money on props, pm me and I'll tell you what you need. :)

[rayzerdesigns]

Nice. To run in P Offshore, I need to be running 4s. I went out today using HobbyWing 180A on each motor. They went into overload. The red light was flashing when I opened her up. Everything was below 90 degrees. I am running TP 3670 motors - 2200kv, with three blade 446 props. After about two minutes she will have this problem. The ESC are version 3 (V3). Strange how both are doing it. I plan on going back out tomorrow and trying again.

I am amazed how it is able to turn on a dime at full throttle like a slot car. I think I found the sweet spot for the batteries. This was my first time out with the ESC's. I hope I can get them to work. A twin drive I need to buy two of everything. LOL

When I figure the problem with the ESC's, I would like to play with props. Try a blade and three blades. What the heck, its only money. I can't take it with me. LOL

I would venture to say with a 36x70 motor a 3 blade 46 is a tad too much prop

[kfxguy]

I would venture to say with a 36x70 motor a 3 blade 46 is a tad too much prop

Agreed not to mention the characteristics of that prop doesn't work well with that hull.

[keithbradley]

Agreed not to mention the characteristics of that prop doesn't work well with that hull.

Based on what?

[Finest Racing]

Hello, sorry for the delay in responding and thank you so much for the suggestions. I think I found some problems. When I checked the ESC, they were not programmed for full throttle. I did do this at the lake individually. Explains why the temps were low and it shut down. I ran the boat again and I had left side ESC went in to protection mode. The temp was 125 degrees. I installed a dual pick up rudder to feed the left side and to continue using the twin pick up from the bottom for the right side. I went back to the lake to try and I had a problem with two battery packs. I called it a day and winter came. I will going this Monday 2-22-2016 to test. When I was able to make runs without any issues, I was able to hit 58 mph using the three blade 46mm. Turning at full throttle as if I was running a NAMBA race. I know, no wake. The water was was not smooth, it was a little rough.
Keith, I will send you a pm on your thoughts about a prop. I have been trying two blade and three blade props. I am looking to run P-Offshore and also P Cat. I am sure I will need to swap props for each class. Thanks and I will make a post Monday.

[TRUCKPULL]

Rob

You said that you have 3670 2200kv motors??
I checked the TP web site NON their.
They do have 4070 2200kv motors.
You also state that your motors have 8mm shafts.
I don't think anybody makes a 36mm motor with a 8mm shaft.

Another question
I am also running a twin Cat for "P" Offshore (NAMBA)
With a 4 min race plus a full mill lap and a Max of 10,000mAMP's onboard (2 - 4S -5000 packs)
you need to keep your AMP draw at or below 60A average per motor to be able to run for 4 1/2 min.

446/3 seems to be too much prop to be below 60A's per motor.

I think this is why you are hitting the low voltage cutoff at about 2 min.

Larry

[Finest Racing]

I do have the TP 4070 2Y 2200kv motors, sorry for the mistake.

Thanks Larry. I found some problems going through the programming. I did notice the full throttle was not set (again). Not sure why I need to keep resetting the full throttle. I am testing tomorrow. I installed two blade 448 props to start with. They spin out. I will post results. Thanks

[Finest Racing]

I went out for the first time since November 2015. I I had the timing at zero, 448 two blade props and I went 59.2 mph. I found out that the first set of batteries were the only set that had a 100% charge. I charged all the batteries a week before. Not sure why all dropped off but the Nano Tech's. I will charge the batteries and try again next Monday.

[TRUCKPULL]

You are running a "Y" wind motor
Why would you set the timing at 0 ????

That motor should be set a 12 Minimum and about 20 Max.
I would say 14 or 15 would be fine.

Larry

[Finest Racing]

You are running a "Y" wind motor
Why would you set the timing at 0 ????

That motor should be set a 12 Minimum and about 20 Max.
I would say 14 or 15 would be fine.

Larry

I had the timing at zero because when I had it at 15 (factory) the ESC was going into default mode. I also noticed other problems. Next time out I will have the boat set up the same with the timing set at 15. I ordered new battery's, current battery's will be topped off the night before. I have no reason for a Y motor. I bought this motor due to the size thinking that it would be efficient. My options with this size were 1650 5D, 2050 4D and the 2200. When I was doing my research on the winds, it became and overload for the brain. LOL
I am going out Monday to test. My goals are to be able to run with timing at 15 degrees, be able to run 4 minutes (running hard) with cool temps. Play with props.

[modvp55]

I have a similar yet different set up. I am running 40x82 2000 KV sss motors. Since they are a d wind timing is at 0 degrees. Our club only runs 4 lap races so that allows for a little more aggressive set up. For this time of year when the water is cool I have run X452 with good results, temps are safe all around. In summer when the water here reaches 80 plus I run X450 to be safe. Props are worked including a minor blade reshape. Both props run nice and free with neutral trim settings. Last week I had 54% left in the batteries after the race but was able to take the last lap easy since had a good lead.

[TRUCKPULL]

Your choice of a "Y" wind is GOOD
They are more efficient then a "D" wind
But there is still a big problem with your AMP draw, to be able to run 4 1/2 minutes.
With only one 4S 5000 pack per motor allowed in NAMBA
As I have mentioned before you need your average AMP draw for each motor below 60 Amp's, or you will KILL your batteries.

I run a twin cat in "P" Offshore
Motors are only 3674 - 1700kv "Y" winds
Props are 442/2 blade, with 2 - 4S - 5000 packs onboard , I run for 4 1/2 minutes and my packs are down to 18%
This works out to 60 Amps per motor average
I am testing with 440/3 blades, the Amp draw is working out to be about 65A average, so I need to cut them a little.

In the attachment you will see that running for 4min. 20 sec. at 60 Amp's --- Your batteries are at your lower limit before you KILL them

Larry

[Finest Racing]

I have a similar yet different set up. I am running 40x82 2000 KV sss motors. Since they are a d wind timing is at 0 degrees. Our club only runs 4 lap races so that allows for a little more aggressive set up. For this time of year when the water is cool I have run X452 with good results, temps are safe all around. In summer when the water here reaches 80 plus I run X450 to be safe. Props are worked including a minor blade reshape. Both props run nice and free with neutral trim settings. Last week I had 54% left in the batteries after the race but was able to take the last lap easy since had a good lead.

Thanks for the input. I think testing is the key, but also having the correct size motors will help.

Your choice of a "Y" wind is GOOD
They are more efficient then a "D" wind
But there is still a big problem with your AMP draw, to be able to run 4 1/2 minutes.
With only one 4S 5000 pack per motor allowed in NAMBA
As I have mentioned before you need your average AMP draw for each motor below 60 Amp's, or you will KILL your batteries.

I run a twin cat in "P" Offshore
Motors are only 3674 - 1700kv "Y" winds
Props are 442/2 blade, with 2 - 4S - 5000 packs onboard , I run for 4 1/2 minutes and my packs are down to 18%
This works out to 60 Amps per motor average
I am testing with 440/3 blades, the Amp draw is working out to be about 65A average, so I need to cut them a little.

In the attachment you will see that running for 4min. 20 sec. at 60 Amp's --- Your batteries are at your lower limit before you KILL them

Larry

Thanks Larry, looks like I need to prop down to be more efficient. I am still baffled of how it ran for about 2 minutes with the 448 props with the heating issues and the batteries were at 80%. I checked the battery's when I arrived home. I think the other battery's were not charged 100%, possibly adding to the problems. If I need to replace the motors to correct the problem, I will. I would like to try to see if I can get them to work, be efficient and to be competitive. With the boat running 59mph, that is where I need to be to run with the others in the class - especially P Offshore. Thanks again Larry. I have new battery's arriving tomorrow and hope to do more testing on Monday. If I remember correctly, we run laps. Our classes are a lap race with time.

[Finest Racing]

I have a thought, thinking out loud (typing). What if I replace the ESC's with Swordfish Pro+ 240? Yes, it be costly $501.28. It would cost less to replace the motors. I understand how the chart is showing the results. Just a thought.