Electric 424 Q500

[gmc]

I will be modifying a Ricochet fus for this soon.

A few questions:

1. What size and c rating battery produces the best results for the legal weight? (Wide open for the heat, land, and put no more 80% of the battery capacity back in)

This is the battery I landed on - 65C 3300mah... Was largest capacity/C rating I could find fitting under the weight limit. Will get some usage data this weekend I hope to see what percent is used.
https://www.dinogylipos.com/products/4s-3300mah-65c

2. Does the nose need to be lengthened? Battery all the way forward?

Just used X mount straight to existing firewall - no lengthening. Any airframe legal for 424 doesn't need modifying for E class. Not sure if lengthening is allowed, but didn't see a need to do so with mine.

3. ESC location and cooling?

I started out thinking ESC on CG with most opportunity for airflow - RX behind - battery in fuel compartment as far forward as possible - but this resulted in too tail heavy a configuration.
I built a battery shelf that slides into the fuel compartment with enough room above for battery - and below for ESC. Holes in firewall allow air in, exit holes in bottom of fuse behind wing.
In my case the shelf is removable - attach battery (velcro) and slide shelf and battery into place... Front wing bolts come in to fuse enough to prevent battery and tray from moving back.
With this config, placed RX on CG... was under minimum weight by a couple of ounces. Added separate gyro also on CG as experiment - and at legal weight. Appears to be within 1/2 ounce of where I think I want the balance - we'll see when it flies. Room for lead in front of ESC without blocking airflow if needed.

Pictures of the set up on a high wing Q500 would be great.

I'll take some pics this evening and post... RevLution high wing, Avian EF-1 motor, Dinogy Lipo (link above), and Castle Talon 90 ESC.
Added arming switch where the radio switch used to be since there is no battery hatch besides wing. Talon has a high capacity BEC, so no RX pack.

Thanks, Dave

[kane]

1. What size and c rating battery produces the best results for the legal weight? (Wide open for the heat, land, and put no more 80% of the battery capacity back in)

I used the Spektrum 3200 100C GEN1 battery. NOTE: Gen 2 battery does not have a balance plug and this must weigh 315g per the rules and they don't make it) Having said all that I have used several different brands, all seem to be just as good as the next. 2700mah or more, and 50C and above and you will be just fine).

Here are some notes I shared from Florida:

Round 1: 1:21 and change. Charged the battery the night before and flew it cold, I put 2000mah back in after the flight.
Round 2: 1:16 and change, put 1800mah back in after the flight
Round 4: 1:18 and change, changed props, and put 1470mah back in after the flight.

2. Does the nose need to be lengthened? Battery all the way forward?

Not sure what a modern airplane needs. I started with old stuff that was expendable. My Scat Cat, uses 1" plastic extensions. I used an AVIAN ESC and exposed the fins out the top of the fuselage. Literally cut a hole in the top of the fuse and pushed the ESC out in the breeze. If one was making a hatch probably could make a version with a hole and one without. I got this idea from Brian Richmond who has been flying a Vortex with an electric motor, different from this set up but conceptually the same. My China Clipper, I had an aluminum adapter made that allowed me to mount my EF-1 motor to the standard aluminum Q500 mounts. In this case it was an old NELSON 3 bolt backplate mount used in 428. And the thrust washer of the Electric is at the same position as it's IC counter part. In both cases I set the CG up to have the battery on the CG, in the beginning, I though I might need to run 5 cells to get the right speed. However, I think we are good with the EF-1 4Cell.

3. ESC location and cooling?

ESC wise see above. Pictures... I haven't gotten there yet. Hopefully, someone jumps in with both feet and shares what they have done. My plan is to cut the top or bottom deck off and replace it with a hatch, if needed I will put a shelf or platform to retain the Batt. The ESC... I plan to cut a hole in the bottom decking and force the ESC fins outside like I did with my other ones.

Hope this helps,

DK

[gmc]

I'll take some pics this evening and post... RevLution high wing, Avian EF-1 motor, Dinogy Lipo (link above), and Castle Talon 90 ESC.
Added arming switch where the radio switch used to be since there is no battery hatch besides wing. Talon has a high capacity BEC, so no RX pack.

A few pics of my RevLution. Thanks to Scotty for the airframe...

[gmc]

A few more pics of my RevLution.

I do like Dan's idea of getting the ESC cooling fins outside the plane.. if I have any cooling issues, I'll make that change...

Greg

[Dave Yost]

Thank you gents!

Great data! I am thinking of a NACA duct (fiberglass) that could be mounted in the top of the front hatch.


Good, Good. I will press.

Cheers, Dave

[gmc]

Thank you gents!

Great data! I am thinking of a NACA duct (fiberglass) that could be mounted in the top of the front hatch.
Good, Good. I will press.

Cheers, Dave

I was thinking of some form of cooling scoop initially - but didn't want the drag/airflow disruption...
Had to open up the firewall for the rear of the shaft with flush mounted X mount and to pass wires - so made it a bit bigger.
NACA duct sounds interesting - look forward to seeing what you come up with!

[Dave Yost]

Well, what goes in must come out....typically at a 3 to 1 ratio, or you loose efficiency and make cooling drag.

Dan's plan maybe the best way forward. Just stick the fins out in the wind and call it good.

Dave

[Sparky]

EF1 racers that I fly don't have any provisions for cooling. I just wait about 30 minutes between flights. I tried some cheap blowers to cool the innards between the flight but didn't really notice any differences. Wait between flights is what I found to be acceptable.
Sparky

[kane]

Sparky, the BEST OF SHOW trophy in your picture was designed and sculpted by Dave's brother Kevin. Dave and Kevin Yost that is. Just letting everyone know who made that trophy. Funny that you are talking to Dave and have a picture of the trophy in your message.

DK

[Dave Yost]

My Brother, Kevin, can bend some tin and weld with the best of them!

I am the odd one of the bunch that spent way too much time in the school house. He's the artist!

Cheers, Dave

[Dave Yost]

This motor was purchased about 5 years ago. Can anyone tell me if it has been revised since then? Or is it still the same configuration?

Thanks!

[kane]

This motor was purchased about 5 years ago. Can anyone tell me if it has been revised since then? Or is it still the same configuration?

Thanks!

That is the current motor.

DK

[Sparky]

Dave, thanks for the worlds largest X-Acto knife!
It reminds me of the Swiss Arm knife display they would have in the store front window that was ginormous with all the attachments going in and out as it rotated.
Sparky

BTW I tried to buy that Rimfire motor at Tower a few days ago and it directs you to the Avian motor. DK told me the Rimfire motor is being phased out and superseded by the Avian motor. At least that's what I think he said.

[kane]

Dave, thanks for the worlds largest X-Acto knife!
It reminds me of the Swiss Arm knife display they would have in the store front window that was ginormous with all the attachments going in and out as it rotated.
Sparky

BTW I tried to buy that Rimfire motor at Tower a few days ago and it directs you to the Avian motor. DK told me the Rimfire motor is being phased out and superseded by the Avian motor. At least that's what I think he said.

Yes, the rimfire was discontinued and replaced with the AVIAN motor. Basically a re-brand. Having said that, the older rimfire motors are still legal, and the 5 year old one in the picture is of a legal motor.

DK

[gmc]

Yes, the rimfire was discontinued and replaced with the AVIAN motor. Basically a re-brand. Having said that, the older rimfire motors are still legal, and the 5 year old one in the picture is of a legal motor.

DK

Well that explains why when I couldn't find a replacement Avian prop adapter - I took a chance ordering the Rimfire one and it was a perfect match....
We won't talk about why I needed a replacement prop adapter for a plane that hasn't left the shop yet...