88" Extreme-Flight Yak Electrified Build

[JagerBomb]

	Quote: Originally Posted by Captain Carlton
	Mark, The lightest the plane gets is about 18lbs even ... with going to more carbon. I thought the issue was mine alone, but I have two identical setups....that I followed here...and these planes thermal out...no doubt. I have seen it in both of mine, plus Matt Stingers Plane. Maybe there are variations in these speed controls. Below are photos from Bakersfield IMAC Free Style. Matt Stringer is a fantastic pilot...but these are photos of his plane thermaling out...and gettin him last place...one minute into the event. Bottom right is an ugly dead-stick. He did a bit of damage. The issues are not isolated or rare. I have moved my ESC down to the bottom box for cooling. However, I have had this plane previously thermal on me probably 8 times...and I don't trust it anymore at all. I have cleared it for use by my 10 year old to fly it for IMAC sequences...but low 3D is banned with the config. The ESC needs to be higher amp draw...down in cowl box. Its not an airframe issue, but clearly the components are being used by us too hard...too close to the edge. Just our experience out here in the. west. If I was buying new for this plane, there no way in hell I would use that ESC. The motor is marginal on power...as has been discussed at great length in a build forum for the Electric AJ Slick 89" at RC Groups. In fact, of all the motor options...it just about the least powerful. I want people to understand this up front if they are throwing down their hard earned cash. - Richard Carlton

Are you sure it is a thermal event? What temp is the esc showing? Could it be your batteries? I ask alot of questions because I've seen a similar circumstance that turned out to be the batteries were going open. I've flown in over 104 degrees with this setup and like I said before, no issues. Also what is your air routing over the ESC? I'm waiting on a AJ Slick and will transfer my power setup to that plane, I talked to Andrew at length about it and he really likes his setup with the Slick which is the A60-18L.

[Captain Carlton]

Mark,

The ESC was running over 200 degrees, and cutting off. We plugged in the Spin box device...and it gave us this info. The Batteries are TP 6S-5000s..Pro Power 30s. The ESC were mounted on the side of the motor box...as shown in this thread...and there wasn't a lot of flow. Ambient temperatures at the time was 75 degrees to 105 degrees.

There must be some variations in MFG of this ESC for there to be this big of a different in performance.

We are using 6S-5000 in series for 12S-5000 for freestyle...and 12S-8700 (four TP 6S-4300 Prolite V2) for IMAC. 12S-5000 just won't be long enough for two sequences....unless you fly a really compressed box. Earlier this year... we ended up dead sticking down to the runway after we flew out of the box on the 2nd sequence. Very demoralizing for my son Alex.

In terms of overall power, if we're at 70% power for a hover (no joke) ...its not much of an energy reserve...if you get in trouble...you can kiss your butt good bye. I have talked to Andrew and Ben Fisher at length. Ben prefers the Plettenburg setup by far. I assume that Andrew uses the AJ Slicks for fun and entertainment. He didn't fly his own design (Gas or electric at TAS)...so make what you will of that.

Andrew is a great guy ... but I have a personal rule about people eating their own dog food.

I have two of the AJ Slick 89's...and for me...they came out a bit heavier than the 88 Yak. My 88 Yak with 12S-5000 was 18.0 lbs with no wheel pants, and CF LG. The Slick with the same config came out at 19 lbs.

All I can say for sure is that we have two groups of people with very different experience with the Hacker gear. I would have greatly preferred to have had your experience...but it didn't turn out that way.

- RC

[Lokiyawl]

	Quote: Originally Posted by Captain Carlton
	Mark, The ESC was running over 200 degrees, and cutting off. We plugged in the Spin box device...and it gave us this info. The Batteries are TP 6S-5000s..Pro Power 30s. The ESC were mounted on the side of the motor box...as shown in this thread...and there wasn't a lot of flow. Ambient temperatures at the time was 75 degrees to 105 degrees. There must be some variations in MFG of this ESC for there to be this big of a different in performance. We are using 6S-5000 in series for 12S-5000 for freestyle...and 12S-8700 (four TP 6S-4300 Prolite V2) for IMAC. 12S-5000 just won't be long enough for two sequences....unless you fly a really compressed box. Earlier this year... we ended up dead sticking down to the runway after we flew out of the box on the 2nd sequence. Very demoralizing for my son Alex. In terms of overall power, if we're at 70% power for a hover (no joke) ...its not much of an energy reserve...if you get in trouble...you can kiss your butt good bye. I have talked to Andrew and Ben Fisher at length. Ben prefers the Plettenburg setup by far. I assume that Andrew uses the AJ Slicks for fun and entertainment. He didn't fly his own design (Gas or electric at TAS)...so make what you will of that. Andrew is a great guy ... but I have a personal rule about people eating their own dog food. I have two of the AJ Slick 89's...and for me...they came out a bit heavier than the 88 Yak. My 88 Yak with 12S-5000 was 18.0 lbs with no wheel pants, and CF LG. The Slick with the same config came out at 19 lbs. All I can say for sure is that we have two groups of people with very different experience with the Hacker gear. I would have greatly preferred to have had your experience...but it didn't turn out that way. - RC

Captain Carlton,

The first motor I had in my 74" Yak was a Hacker A60 24S. Turning a 20" x 10" APC put the amps right at max for the motor and I was also at about 70% power to hover with that setup which I also felt was too weak. The motor also ran hotter than my Eflite Power 160 or the Pletty, despite the latter making a lot more power. I know of one person that burnt one of these up in this same plane so I tried to be careful to not repeat that.

I mounted the Masterspin 99 Opto on the bottom of the motor box thinking that the airflow might be the best there due to the bottom of the cowl being open there. I just got a spin box so will check actual temps but from just touching the ESC after a long flight I can tell you that mine comes down just warm, never hot. My Eflite setup was pulling 90 AMPS WOT on the 20" x 10" APC. Switching to a Xoar prop dropped that to 81 AMPS. The Pletty is turning a 22" x 12", makes more power but draws less than the Eflite, about 79 AMPS.

I am very curious about how your Yak flew with the 8700 mah setup, did it feel excessively heavy to you? Was it really noticeable?

Thanks,

James

[JagerBomb]

	Quote: Originally Posted by Captain Carlton
	Mark, The ESC was running over 200 degrees, and cutting off. We plugged in the Spin box device...and it gave us this info. - RC

Did you cut out the covering on the end of the fuse behind the ESC? This will increase the airflow over the cooling fins. The ESC also has an adjustment for thermal cutoff. It defaults at 100c which is 212f. Mine is still at the factory setting. Possibly you could set it higher due to the what I assume to be full throttle settings you're using for the IMAC routines. The Plety stuff is very nice, but you're talking well over double the price and even more than that on a 120 amp plus ESC. Also realize I've been flying mine in the stock configuration at 18.5 lbs, which would put a higher load on my system. I would go back and reck all my setting with the spin box.

[Captain Carlton]

Ok, well I have solved the ESC cooling issue. Its still a a bit gutless...but now the ESC cooling is fixed. Photos attached...

[cjdscratch]

Captain,

Have you tried the APC 25x12.5E prop on this setup? If not I believe this is your power problem with this setup. Many have tried this setup with Zoars and other wooden props. But non of them perform like the APC E props. 24x12E is another APC prop others have tried and liked on the 18L. I hover my 18.5lb Slick at 1/2 throttle and it has plenty of pull out with the 25x12.5E. Its not foamy rocket power but it is plenty. Give it a try I bet you will be surprised......

Chris

[Captain Carlton]

Hey Chris...I appreciate the ideas. I started off with the APC 24x12 and then used the APC 25x12. The good news is that the ESC is actually cold...upon landing. I didn't need it cold...just not 200. :-) Thanks for the suggestions.

[Lokiyawl]

Captain Carlton,

Glad to hear that moving the ESC out into the breeze seems to have solved your thermal problems.

I wanted to ask if anyone out there has considered doing an electric 110" EF Yak as of yet? It looks like the Pletty Predator on 12 or 14S would be really strong. The motor is able to do 15,000 watts which is a staggering 20 HP electric which is double a DA 100 and interestingly about the same price... Half of that would give 250 watts per pound if the plane went to 30 lbs. Would need approx. 6 lbs. of Lipo, maybe 4 x 6S 4000MAH for a 12S setup and probably turn about a 28" prop. I have been comparing the ratios of battery to all up weight on planes from foamies up to my 74" Yaks and find that a ratio of about 20% battery tends to yield 9-10 minute flight times on all of them so maybe this would also apply to the 110"? If anyone has any thoughts on a project like this, let me know.
James

[exeter_acres]

Dan Landis set one up/.....

this is what he sent us:
The Specs: Futaba 9157's on everythin,g Futaba 2.4 ghz rx, Motor Reaper Brushless GR85, ESC Castle Creations140HV,
Batteries Tanic 12s2p 9000mah, Rx Batteries, 2x 2s1p 3500mah,
Prop Mejlick 24x10, Weight 25lbs 5ozs, Transmitter Futaba 14MZ 2.4

There is a pic here:
http://www.extremeflightrc.com/html/pilot_gallery.html

Just scroll down a bit and you'll see it...

[Lokiyawl]

Exter,

Thanks for the link. I am amazed at how light Dan's plane came out and his battery pack is almost as large as what I was thinking. Does anyone know off hand the weight of the GR85? It does not seem to show up in my initial searches. I would be really interested to find out how Dan's flight times came out, do you know how I can contact him? Any comment on the best flying weight for the 110" EF Yak?



Thanks,

James

	Quote: Originally Posted by exeter_acres
	Dan Landis set one up/..... this is what he sent us: The Specs: Futaba 9157's on everythin,g Futaba 2.4 ghz rx, Motor Reaper Brushless GR85, ESC Castle Creations140HV, Batteries Tanic 12s2p 9000mah, Rx Batteries, 2x 2s1p 3500mah, Prop Mejlick 24x10, Weight 25lbs 5ozs, Transmitter Futaba 14MZ 2.4 There is a pic here: http://www.extremeflightrc.com/html/pilot_gallery.html Just scroll down a bit and you'll see it...