Which motor and esc for 6s rigger Lehner or NEU

[StevenBryant]

Hey guys

I'm building a 6s rigger for oval racing and would like a bit of advice on which motor to run. The two that i am looking at are:

Lehner 2250/7 LK 1691kv

and the NEU 1527 1.5D 1500kv

Also esc recommendations would help, i'm Looking at the MGM TMM28026-3 esc but if there are better or more suitable i would appreciate your advice

cheers

Steve

[Make-a-Wake]

They should be nearly identical in output so i like the higher kv Lehner........................my vote

[Fluid]

The Lehner's true Kv is actually a lot higher than the Neu's. Lehner rates their Kvs under load, Neu (and Leopard and TP and etc.) does not. Figure around 15-20% higher Kv on a Neu (4-pole) to equal that of a Lehner (2-pole). So the two the OP is considering are actually pretty far apart.

That said, the Neu will spin slower but it will pull a larger prop. Of the two, I'd go with the Neu, expect loaded rpm in the 29,000 range depending on load/prop. The Lehner will be in the 35,000 rpm range with a smaller prop. Depending on the water conditions and rigger size, the larger prop may stay hooked up better. Or not.


.

[photohoward1]

Lehner...every day.

[electric]

The Lehner's true Kv is actually a lot higher than the Neu's. Lehner rates their Kvs under load, Neu (and Leopard and TP and etc.) does not. Figure around 15-20% higher Kv on a Neu (4-pole) to equal that of a Lehner (2-pole). So the two the OP is considering are actually pretty far apart.

That said, the Neu will spin slower but it will pull a larger prop. Of the two, I'd go with the Neu, expect loaded rpm in the 29,000 range depending on load/prop. The Lehner will be in the 35,000 rpm range with a smaller prop. Depending on the water conditions and rigger size, the larger prop may stay hooked up better. Or not.

.

It's the "real world " vs. the "math" world of what a given prop and motor will do that keep this hobby interesting...

[keithbradley]

Definitely take what Fluid said into consideration. The LMT motor is a lot higher RPM motor on the same voltage. This isn't necessarily a bad thing as LMT motors are best at higher RPM, but it is something to consider when selecting a prop.

I strongly recommend going with Lehner if you choose to run a MGM 28026.

[flraptor07]

The 28026-3 X-2 series lite ESC is a awsome ESC I've got two of them, ESC wise they are the same as the 28026-3 X-2 series Pro and the 28026-3 X-2 series. Except they don't have as many bells and whistles but the still have data logging and they are $100-$125 cheaper.

[Doug Smock]

I strongly recommend going with Lehner if you choose to run a MGM 28026.

Do the MGMs and NEUs not play well together?

[keithbradley]

Do the MGMs and NEUs not play well together?

Sometimes. Some people have had little or no trouble, some have had headaches that would just not go away.

[Doug Smock]

Sometimes. Some people have had little or no trouble, some have had headaches that would just not go away.

Do you know if the issues were just with D winds? Problems starting/ finding direction?

Sorry to hijack your thread Steve.

[keithbradley]

Do you know if the issues were just with D winds? Problems starting/ finding direction?

I've heard of issues with both D and Y. I think it is similar to the issue some people have experienced with D winds and old Schulze ESCs, but I don't think it's limited to (or automatically an issue with) just D winds. There's a guy at our Flint events that runs D wind 4 pole motors in his twin cat with MGMs (not Neu but same design) and has them working pretty well at around 100mph, so it definitely can be done. He did have some issues with the ESCs shutting down every time he hit full throttle at one event but he found a way around it somehow (I don't recall what he changed).
There was a European guy on this forum last summer searching for help with a Neu/MGM setup. I think his issue was poor commutation at higher RPM but it was a while ago so I'm not certain.

We've seen this with other more popular ESCs too, but it's not as obvious. Most times I think people don't even know it's happening with some ESCs. It seems to be more related to "batch" of motors and perhaps the quality of magnets than to wind, although I'm sure certain configurations are inherently more problematic/sensitive than others.

[Doug Smock]

Ok thanks Keith. I'm working with someone on a project and may have to send him another direction. Time to go to work.

D.

[RaceMechaniX]

Both motors are good options, but perhaps favor slightly different set-ups. As Fluid pointed out the KV of a Lehner is under load compared to the majority of other brands which are measured under no load. Typically you can expect between 10-20% reduction in RPM under load depending on the wind and motor.

The 1527 1.5D will turn a larger prop at lower speeds compared to the LMT which prefers higher RPM. This is a result of the 4-pole Neu versus the 2-pole LMT. The LMT will have limited torque output compared to the Neu unless you push really high currents which it can do, but this becomes a controller limitation. The LMT will favor a lighter boat with a 1P setup while the Neu will push a heavier hull. Another option you have not considered is the Castle 1717 1Y, which is an excellent Q hydro motor for a lighter set-up. A 1717 won last years Q and T hydro at the NAMBA FE Nats and I dare say its power was respectable, but not overkill. The 1717 and 1527 1.5D or the 1Y are closely matched with a nod to the 1527.

In regards to the controllers, if you select a LMT a MGM28026 or a 25035 are excellent matches. Either MGM should drive a 1527 1.5D without much effort. The MGM's have some current limiting techniques that prevent the low winds (1D and 1/2Y's) from running well with high currents. Castle's Hydra ICE 240 or a converted ICE 200 Lite also work great with either motor. Both ESC's have data logging and are reasonably compact to install besides a 6S battery.

I have run the 1717 and several different 2250 winds and like both. Likewise I have run both motors with the MGM and Castle controllers and did not see any difference from the controllers. Motor length and packaging must also be considered as a competitive Q boat is probably close to the 40" limit at least in NAMBA. Squeezing a 1527 and a 6S battery inline with a controller limits installation and CG placement so worth a check before ordering.

TG

[StevenBryant]

Thanks for your feedback guys, Doug you are more than welcome to hijack the thread......

The weight of the rigger will depend on the batteries that i run, my plan was to run either 2 x 6s 4000mah at 1.4kg or 2 x 6s 3300mah at 1.1kg, running two pack with give me better weight distribution and will help me hit the sweet spot on the COG easier. my other option is to rum a 5000mah that weighs 0.750kg but this may cause problems due to lower capacity.

What is the minimum capacity i should be running on the batteries?

What sort of weight should i be aiming for the rigger fully loaded?

cheers
Steve

[StevenBryant]

My running weight will be around 7.5lbs if i use the 2x 6s 3300mah and 8.1lbs with 2 x 6s 4000mah, would this be considered under weight, over weight or spot on. These weight are based upon a Lehner 2250 motor weighing 560 grams.....

[Make-a-Wake]

Another option you have not considered is the Castle 1717 1Y, which is an excellent Q hydro motor for a lighter set-up. A 1717 won last years Q and T hydro at the NAMBA FE Nats and I dare say it's power was respectable, but not overkill.

The 1717 is my favorite motor so far, have one in my 39" Mono and it hits 60+ on 6s2p. Its a very good product.

[RaceMechaniX]

I run a single 6S 6000mAh pack for heat racing and use ~4400-4800mAh. 5000mAh is sufficient for a light boat, but you will not be doing too many extra laps before you run into problems. Off hand I do not recall what mine weighs, but it is light.

TG

[NativePaul]

Steven is this for Hydro 2/Formula 4, or the new SWARM "run what you brung" class?

If it is for Hydro2 or Formula 4 both of the motors in the first post will be too big I would be looking at Lehner 1940/1950 or Neu 1415/1512/1515.

If it is for run what you brung it is hard to advise with the course and runtime being decided on the day, you would need a LOT of battery with the big motors if there are a lot of Monos or ECOs and the run time is 6 minutes+. I don't think I would go for a hydro though in case the course was an M or triangle and you needed to turn both ways. Maybe you know a bunch of guys have or are building sprint oval boats for the class, in which case ignore what I said in this paragraph and let me know, as I have wanted to do some competitive sprinting for a while and that would get me to a few SWARM races despite it being out of my area.

[StevenBryant]

Hi Paul

This boat has been designed for racing 6 lap oval/circuit and if i get chance i will take it to this years SAW racing just for a bit of fun, my plan is to get the boat running in the low 70 for circuit and for SAW racing who knows.....

The classes we will hopefully run are:


OPEN Hydro (Riggers cats and classic hydros)
Open Mono

Any size and any number of cells, 6 laps no recovery, we have kept the classes open to try and attract as many people as possible, on the race days we will also be running 21 and 45 riggers, and Gas monos and cats.

If the race events start to take off i'll let you know so you come down and join in.

This is nothing to do with SWARM

[StevenBryant]

Would you guys recommend using a 1/4 or 3/16 flexi with the Lehner 2250/7 motor?

[RaceMechaniX]

3/16" holds up pretty good. I have not had any problems although I run a square drive on the motor side so no thrust forces on the cable. If you run a 1527, 1/4" would be safer.

TG

[StevenBryant]

Thanks Tyler

3/16th flexi it is t go with the 2250/7.

Cheers
Steve