wedoitall
Member
Yes they do
Yes they do
Aeroplayin
70cc twin V2
Another thing to remember is that the big concentric bearings are going to be important for the high levels of angular momentum we run into with big props spinning fast in 3D maneuvers, and 12S means upping the RPM levels. For well-designed motors, like Hacker and Motrolfly, bigger bearings translates to weight. The 595 to 650 gram range is what I would expect from a motor that will need to manage a 21x10 to 7000 RPMs. Asking a lot from a 500g motor has always concerned me. The 155 degrees of heat that Ken says to limit the 4330 to can easily be exceeded here in Florida with the wrong prop on small light motor with smaller bearings, and this could cause expensive problems. This was always my concern because we've seen rotor temps hit 185 in Hackers when we were pushing the A60-16M in the summer, but never saw any adverse effects or any power/performance sags from hot running Hackers. I don't even worry about heat anymore with the 14 or 28 pole Hackers. We use temp stickers right on the rotor that trigger a color change when certain temps are hit. I was also told by Castle that their ESC's are designed to run up to 212 degrees too, and I never saw any problems with them when we saw temps over 165 on the logger. So I've been comfortable with the Hacker/Castle combo until the Ice2 went away and when we discovered that the Edge HV's can't interpret 28 pole motors well.
The specific 155 degree restriction is why I have been reluctant to try the 4330 and I always thought that this was why Ken tried to limit my prop size selection on the 12S setup. Of course, Motrolfly motors run cooler than Hacker, and I've always pushed them beyond Ken's suggestions. But the cost of mistakes are a bit different with a 78 than my using a 14x7 on a 4S with a 2820-750Kv on a 48 EXP. 12S on the A60-8S with a 21x10 Falcon and a Gecko OPTO ESC would be the test because the 21x10 to 6400 is just a bit underpowered for the 78, and 6800 to 7000 RPMs would be perfect. 12S on a 188Kv, I think, should do it.
The specific 155 degree restriction is why I have been reluctant to try the 4330 and I always thought that this was why Ken tried to limit my prop size selection on the 12S setup. Of course, Motrolfly motors run cooler than Hacker, and I've always pushed them beyond Ken's suggestions. But the cost of mistakes are a bit different with a 78 than my using a 14x7 on a 4S with a 2820-750Kv on a 48 EXP. 12S on the A60-8S with a 21x10 Falcon and a Gecko OPTO ESC would be the test because the 21x10 to 6400 is just a bit underpowered for the 78, and 6800 to 7000 RPMs would be perfect. 12S on a 188Kv, I think, should do it.
Last edited by a moderator:
Ohio AV8TOR
Just Do It
So I received an email from Ken today about the winds on the 4330 for 12S and 216kv is not the lowest he can go. He said he could do a 195kv for $10 more. So looking at numbers with it on a larger prop look like this. I would be interested in your thoughts.
21x10 on 12S @ 195kv = 3365w - 6.53 flight time with 3,300's - 26.48 lbs thrust
22x8 on 12S @19kv = 3243w - 6.78 flight time with 3,300's - 23.92 lbs thrust
21x10 on 12S @ 195kv = 3365w - 6.53 flight time with 3,300's - 26.48 lbs thrust
22x8 on 12S @19kv = 3243w - 6.78 flight time with 3,300's - 23.92 lbs thrust
Enterprise
150cc
We triedXoar 25A and B on Gary's 91 with same setup and he did not like either one. 25a had no speed and 25b was too much load.
I have a Vess 25B I am dying to try on my PTE-72.
I have my 60/RE2 on a giant stick running a 23x12 at the moment.
We keep coming back to the Mej 24x10TH.
I have a Vess 25B I am dying to try on my PTE-72.
I have my 60/RE2 on a giant stick running a 23x12 at the moment.
We keep coming back to the Mej 24x10TH.
Last edited by a moderator:
Aeroplayin
70cc twin V2
Tom flew Frank's DA60 with the RE-2 on the 25A to 6930 RPMs and 41.7 pounds of thrust on the Rapala digital scale. He flew the Xoar 25x10 Beech the same weekend. About a pound less thrust because of the lower RPMs, but a little more pitch speed, it seemed. I took three videos with the 24x10 Lam Xoar, the 25A and the 25x10 beech, but I think you saw them already, Roger. Frank has the 24x10TH now and we'll get that videoed soon. But I know from experience that the 24x10TH will only pull about 38 pounds at 6900. I'm guess that with the pipe, it may go to 7100. Just not sure.
Last edited by a moderator:
Aeroplayin
70cc twin V2
Also, the Mejzlik 24x10 standard will spin faster than the 24x9 Falcon CF on the same engine, and the Mejzlik 24x10TH will spin faster than the 24x10 standard. I've confirmed this with someone else who tried them on the GP61, so if anyone has any different experience with them, please let me know.
Bigroger
70cc twin V2
I've also tried the Mej 24x10TH on this setup and maxed out at 6750rpm. Vess carbon 24B bumped it up a bit then the wood Vess is like ... WOW. But thats 24B not 25A or B. If the larger vess wood can spin at least 6800rpm it should be pretty impressive I think, depending on how it spools up etc.
I am yet to be happy with the Mej on anything that cannot spin it at 7000+ rpm.
On the electric 12s setup I had it was amazing, and spun over 7400rpm peak. No issues, very nice.
I haven't tried the Mej on the DA70 yet, I'll do that next time out to compare.
The DA70 stock is spinning the Vess carbon 24B at over 7200 rpm now, still a little rich in the mid range and top end, can't wait to see where the twin will end up once fully broken in!!!
I'll use the Mej 24x10TH on the 91" extra when ever I'm flying IMAC comps. Its much quieter then the wood and carbon Vess, with the wood being the ear tearing loudest by far
Aeroplayin
70cc twin V2
The problem is still if the 500g motor can handle a 21 and 22 prop to these RPM levels. Did you ask Ken straight out if you should do this? I'm in, if the answer is yes. 24 to 26 pounds is the type of performance that will transform the 78 Extra into something you will always want to have in your hangar. The 22x10E Mejzlik on the A60-16M on 10S was peaking at 3700W and 7000 RPMs at 95A with 24.5 pounds on the ground, and settle in at about 2875 and 77.7A in the air at 7011 RPMs. It was effortless power on the 13.4 pound 78.
As far as flight time with 12S, I'm going to guess that 480 to 520 mAh per minute on good batteries is going to be the norm on a peak 73A for Tom -- your 3243W divided by 44.4v -- and 420 to 450 for me. This means a minimum of 5.5 minutes on 3300's for Tom and maybe 6.5 for me. The Gforce Elite batts I'm using on 5S have a 6S 40C 4000mAh battery that's going to come in at a very light 41 ounces for the 2-pack. That would give me almost 8 minutes.
Enterprise
150cc
I have not run the Falcon 24x9 yet on the DA-60 pipe setup, but on Patrick's stock EME-60 we get 6550 on the 24x9 and 6350 on the 24x10TH. He is going back to the 24x9. On Gary's DA60/RE2 we were getting almost equal RPM numbers on the Mej 24x10 and 24x10TH, 6800 RPM or so.