Prop recommendations for Carbon TFL Pursuit cutting out on 6s

[Addicted]

Hi, I'm running a Leopard 4084 X2 2200kv / seaking 180 on 4s/6s. I just got a prop from dashbota (3 blade...) it rips on 4s but destroyed a new gens ace 120c (battery's get hot on 4) and on 6s I can only get about half trigger till it will cut out on me. I'm thinking a prop issue or needing a bigger ESC maybe? I would apricate any recommendations.

[Xrayted]

Its too hot of a setup and pulling too much current. Most 6S heat racing setups use 1600-1900KV motors. Current draw goes up drastically with RPM, so your 2200s are running about 7,500 RPM more on 6S than a more typical 1900 KV setup does. That's great for SAW like drag racing for a few seconds, but then you must cool down for a bit or else you will burn things down if run constantly. My 1900KV 6S setup pulls more than 200A easily, so your 180A ESC is likely shutting down due to over current. Seaking ESCs are rebranded Hobbywing ESCs, and they are known for being very intolerant of over current, even in the airplane and RC heli world where I have used them as well despite those models not pulling near as many amps as boats do.

Your motor KV setup is a proper 4S setup though......maybe. Because many of Dasboata props are for SAW straight line speed runs, not constant wide open heat racing unless you specified that, so you might struggle with overheating even on even 4S with that prop. You need to take it slow and check the temps after every minute or so until you can establish how that prop setup is going to work being run for 2-3 minutes at a time

If you want to stick with 6S, you will need to prop down and take some load off the electronics, or invest in an ESC than can handle it without shutting down, but heat will still be something to keep and eye on. The smaller Castle MX8 ESC converted to water cooling will hang into the 250+ amp constant and still not shut down, and handle transient current spikes much higher than that for short periods. And it has data logging which is very helpful at testing various setups/props. I love mine, and I have few of those 180s laying around in my parts box because of the same shutdown issues your are experiencing.

You can buy the Castle ESC already pre converted to water cooling directly from the guy that makes the cooling plates if you dont wish to do the conversion yourself . https://stumpfabrication.com/collect...s-marine-ready

Castle also sells an even bigger MX12 that is already water cooled from the start, but its a good bit bigger and heavier than the 8, so it depends on the size of your boat

[Addicted]

Its too hot of a setup and pulling too much current. Most 6S heat racing setups use 1600-1900KV motors. Current draw goes up drastically with RPM, so your 2200s are running about 7,500 RPM more on 6S than a more typical 1900 KV setup does. That's great for SAW like drag racing for a few seconds, but then you must cool down for a bit or else you will burn things down if run constantly. My 1900KV 6S setup pulls more than 200A easily, so your 180A ESC is likely shutting down due to over current. Seaking ESCs are rebranded Hobbywing ESCs, and they are known for being very intolerant of over current, even in the airplane and RC heli world where I have used them as well despite those models not pulling near as many amps as boats do.

Your motor KV setup is a proper 4S setup though......maybe. Because many of Dasboata props are for SAW straight line speed runs, not constant wide open heat racing unless you specified that, so you might struggle with overheating even on even 4S with that prop. You need to take it slow and check the temps after every minute or so until you can establish how that prop setup is going to work being run for 2-3 minutes at a time

If you want to stick with 6S, you will need to prop down and take some load off the electronics, or invest in an ESC than can handle it without shutting down, but heat will still be something to keep and eye on. The smaller Castle MX8 ESC converted to water cooling will hang into the 250+ amp constant and still not shut down, and handle transient current spikes much higher than that for short periods. And it has data logging which is very helpful at testing various setups/props. I love mine, and I have few of those 180s laying around in my parts box because of the same shutdown issues your are experiencing.

You can buy the Castle ESC already pre converted to water cooling directly from the guy that makes the cooling plates if you dont wish to do the conversion yourself . https://stumpfabrication.com/collect...s-marine-ready

Castle also sells an even bigger MX12 that is already water cooled from the start, but its a good bit bigger and heavier than the 8, so it depends on the size of your boat

Thanks that helps a lot. I have an extremely heavy trigger, especially when I have a speed meter in my boat and when people are watching. I did just buy X2 4082/1600 KV for my UL19. do you think that might be a little better with the 180 and Prop down? Then I?ll stick the other one in the euro 19 with a bigger ESC. I?m pretty frustrated because I actually just bought 3 of these 180s from OSE for a few of my different boats and all of them go into low power mode around 3.78v even when I lowered it down to 2.8v cutoff.

I actually have a brand new max 8 in a box I was going to put in my Tekno. To make it Marine, do you just put a cooling plate on the bottom?
Thanks for the tips


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[Xrayted]

Yes, in the heli world we completely disable the LVC on ANY Hobbywing ESC, otherwise it will do the same and shut down in flight despite not being anywhere near the set LVC values. You will destroy a 2K heli in seconds if you dont know how to safely auto down.

1600 KV will reduce the current draw down a good bit, and you may be fine with 6S on the 180 ESC with no other changes but the motor KV, but the Dasboata prop is the wildcard here. It will require some testing and checking as described above to make sure all is OK.

6S on 1600KV is about 1,000 more RPM than your current 4S setup on the 2200. Speeds should be same of faster, however the higher voltage 6S combo will work in your favor as higher voltage means lower amps for the same amount of work. The higher voltage setup will have more peak power and not sag under load as much due to the lower current required, as current is what drags the voltage down.

Explore the Stumpfab site I linked above for the RTR M8 cooling plates he makes. You will need the plate, some thermal paste or epoxy, and then one of the 3D printed covers he makes to hold it all together since you must remove the top cover and factory fan and fins. About $75 worth of stuff to convert the one you have, assuming you dont already have the thermal paste which isnt cheap.

[Addicted]

Yes, in the heli world we completely disable the LVC on ANY Hobbywing ESC, otherwise it will do the same and shut down in flight despite not being anywhere near the set LVC values. You will destroy a 2K heli in seconds if you dont know how to safely auto down.

1600 KV will reduce the current draw down a good bit, and you may be fine with 6S on the 180 ESC with no other changes but the motor KV, but the Dasboata prop is the wildcard here. It will require some testing and checking as described above to make sure all is OK.

6S on 1600KV is about 1,000 more RPM than your current 4S setup on the 2200. Speeds should be same of faster, however the higher voltage 6S combo will work in your favor as higher voltage means lower amps for the same amount of work. The higher voltage setup will have more peak power and not sag under load as much due to the lower current required, as current is what drags the voltage down.

Explore the Stumpfab site I linked above for the RTR M8 cooling plates he makes. You will need the plate, some thermal paste or epoxy, and then one of the 3D printed covers he makes to hold it all together since you must remove the top cover and factory fan and fins. About $75 worth of stuff to convert the one you have, assuming you dont already have the thermal paste which isnt cheap.

I completely missed the link. Thanks.

I?ll start with the new prop.
I appreciate all the advice
Now I just need to figure out what prop to get.
I?ve been lazy and I haven?t wanted to balance any of my own so I?ve been just getting everything from Chris. (Burning ESC with a big smile).


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[Xrayted]

Not sure how big your boat is, but my 36" TFL mono does well on 6S with 42-43mm props in the 1.6 pitch range. It really moves with a 1716 (43/1.6), which is also the same size prop used on lot of the RTR Pro Boat models. The $20 CNC props from OSE are good to test various combos out without breaking the bank, and they are sharpened and balanced already close enough to just install and go. The negative is they are thin and bend easily, so I will typically source a better quality prop once I know what works.

Increasing a props diameter increases the amp load more significantly than increasing its pitch. Pitch is a more linear current change, but diameter changes ^4, so I have a fresh smaller diameter prop with a 1.9 pitch that is higher total pitch than my current prop, so should be faster on paper with hopefully only moderate if any current increase. I plan to test this weekend and compare data logs and top speed to see if the math matches real life. It has been quite close for me so far.

Good luck!

[ray schrauwen]

Check your driveline for drag and rubbing. Do you leave a 3/16" gap between strut and drive dog?

[tbonemcniel]

It's the SK180, for now. That's what's shutting you down. They're notorious for doing that. It could be doing that for 2 reasons. 1, LVC. I disable LVC on all my boats to avoid early shutdown. I also run two batteries in parallel to keep the voltage sag to a minimum, to ensure I have enough capacity to make my runs, and just so the batteries can handle the amp draw I ask of them. Try a run with LVC disabled. If it works, you can either leave it disabled, or get better/more batteries to lessen the voltage sag and re-enable LVC. Better should mean a higher C rating, but in the real world it doesn't. There are a number of 65C or 70C batteries that have a measured C rating much better than many labled 120C batteries.

The SK180 could also be shutting down on over-current. They're not very powerful ESC's relatively speaking. Most of my boats draw in the 250-300A range continuous, some a little higher. No way can a SK180 hang with that kind of amp draw. Even in a twin 34" mono I have, one of the SK180's would shut down on the straights, ended up replacing them both with Castle X8S's and no more issues. I run Castle ESC's in almost every one of my boats. They can take what I ask of them and not cry about it lol.

For me, I keep getting rid of weak links in a boat until I can't do anymore. ESC can't handle the amps? I'll put one in that can. Batteries/connectors/wiring can't handle the amps? I'll put some in that can. Cooling not keeping up? I'll re-work it and upgrade it until it can. The only limiter I'll accept on my boats, is battery capacity. I'm a racer, so I'm limited to how many mAh I can carry. When my boats run out of juice without completing 6 laps plus a penalty, that's when it's time to back off. I won't let inadequate components like an ESC, motor, or cooling capacity be what causes me to prop down.

[Bande1]

4s - abc 1716-17-45
6s 1614-17-45, octura x640, prather 215

[Addicted]

4s - abc 1716-17-45
6s 1614-17-45, octura x640, prather 215

Thank you!


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[Addicted]

I just bought a hydra and the props that recommended.
I?m first going to try it in 4s with the batteries in parallel. I?m was using Gens Ace 6800 120c. I just got some 5000 Purples 4s, I?ll try running those in parallel and see if I have heating issues on the batteries with those.
I don?t have any temperature issues on the ESC or the motor though I?m running a dual pickup OSE Rudder.
I guess it all boils down to the super cool prop is just too much for my SK.
Thanks for all the help! I got some props on the way and I?ll be testing soon!


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[Xrayted]

You can revisit the custom prop once you have the Hydra installed since it will be able to tolerate a lot more current without shutting down. Heat becomes the new problem to keep and eye on though

[ray schrauwen]

If that is the stock shaft it's fine but if it's an upgrade the drive dog is too close to the strut and needs space for the shaft to compress.

[Addicted]

If that is the stock shaft it's fine but if it's an upgrade the drive dog is too close to the strut and needs space for the shaft to compress.

It?s the stock two piece junk. OSE is out of stock of the one piece for the stinger.


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[ray schrauwen]

O.k. how do you lube it?