BJ Craft Eternity
11-22-2018, 04:03 PM
#54
I finished it up and, weather permitting, I’ll put the maiden on it tomorrow. I couldn’t wait to hear the drive and was really happy when I applied electrons to it for the first time. Man is it sweet. Very very quiet.
The build finished up smoothly. I used the supplied air baffle template and made a foam baffle. It fit perfectly first shot. I installed a cf/nomex tray and cf square rods for the battery tray. Very light setup.
I set the tray position by checking CG. It is supposed to be 130mm from the LE, which also works out to be 80mm from the face of the wing/fuse mount. As I mentioned before, I am using the RoaringTop 5800mah batteries. I ran these in my Eternity with great results. It gives me plenty of extra juice for long/windy F19 flying.
I am using a powerbox digiswitch and 800mah battery for a backup system aling with the Mezon 130a ESC with its BEC set for 8v. I’ll probably go to a smaller backup battery in the future but this gives me plenty of battery capacity for sitting in the pits and messing around with mixing etc. without connecting the mains.
I am using the Falcon 22x22 F&R. B.J. recommends this combo. I was going to use the Mejzlik props like on my Eternity but he felt the Falcons were better and consumed less power. They are a bit lighter as well.
My weight is still fine, even with the heavier batts. I am 4950.
I also installed the rear CF rudder plate. B.J.says this helps in tracking etc.
Here are some pics and I’ll update everyone once it is airborne.
The build finished up smoothly. I used the supplied air baffle template and made a foam baffle. It fit perfectly first shot. I installed a cf/nomex tray and cf square rods for the battery tray. Very light setup.
I set the tray position by checking CG. It is supposed to be 130mm from the LE, which also works out to be 80mm from the face of the wing/fuse mount. As I mentioned before, I am using the RoaringTop 5800mah batteries. I ran these in my Eternity with great results. It gives me plenty of extra juice for long/windy F19 flying.
I am using a powerbox digiswitch and 800mah battery for a backup system aling with the Mezon 130a ESC with its BEC set for 8v. I’ll probably go to a smaller backup battery in the future but this gives me plenty of battery capacity for sitting in the pits and messing around with mixing etc. without connecting the mains.
I am using the Falcon 22x22 F&R. B.J. recommends this combo. I was going to use the Mejzlik props like on my Eternity but he felt the Falcons were better and consumed less power. They are a bit lighter as well.
My weight is still fine, even with the heavier batts. I am 4950.
I also installed the rear CF rudder plate. B.J.says this helps in tracking etc.
Here are some pics and I’ll update everyone once it is airborne.
11-25-2018, 04:42 PM
#59
I was able to put some flights on the Eternity this weekend. The Eternity and XDrive are a really nice combination. I am very impressed with the XDrive. It is super quiet and very smooth.
The Eternity flies very nice and is pretty close to what my friend Jean-Paul Delteil described with the Immortal. It presents very well, snaps extremely well, spins great, and has a good overall pace. Knife edge performance is pretty unreal.
I have a lot of fine tuning to do. It has a bit of a pull on power off downlines that I am mixing out with Throt/Elev mix. So far it looks like Knife Edge is fine but I’ll wait and see how it all shakes out.
So, initial results are very good with the Eternity.
The XDrive has a lot more power at the top end than needed. In fact it is really a very “torquey” setup. I’ll post more on that on the XDrive thread. I flew it with power dialed back to 80A max (it will peak over 120 on the Falcon 22x22 setup). I may dial it up slightly but it really has the power I need.
I’ll post more as I get this thing dialed in. Both of my flying sessions this weekend were cut short by fire authority helicopter rescue practice at my field so I only have 6 flights so far. More to come!
11-28-2018, 03:00 PM
#60
Congratulations on a successful maiden of your Eternity. I have one on the way. Regarding placement of your Mezon ESC and back up battery...….were they placed at the rear of the battery compartment to achieve your desired CG? In other words, if they had been mounted farther forward, would you have had a balance issue? I'll be using a Kontronik Jive Pro 120A ESC with a backup battery. That combination weighs about the same as your setup so I was just wondering about equipment placement and CG.
Mike
Mike
11-29-2018, 03:08 PM
#61
Mike
I stuck the backup batt and ESC there for ease of wire routing and to limit the number of extensions I needed. They could slide forward. I actually made my tray a bit longer than stock so I have room to mount the battery to the rear for the heavier packs and I can install lighter packs all the way to the front. If I switch to lighter 5000mah packs then I would also move the ESC and battery forward.
I stuck the backup batt and ESC there for ease of wire routing and to limit the number of extensions I needed. They could slide forward. I actually made my tray a bit longer than stock so I have room to mount the battery to the rear for the heavier packs and I can install lighter packs all the way to the front. If I switch to lighter 5000mah packs then I would also move the ESC and battery forward.
11-29-2018, 06:23 PM
#62
Thanks for the information. Can I assume that with the backup battery and ESC in the position shown in your photo, the Eternity balances at the location recommended by BJ Craft? Not sure when mine will arrive as it's on order from the factory.
Mike
Mike
02-09-2019, 04:53 PM
#65
Hi there,
Sorry for the lag in updating. But I have been flying the Eternity and XDrive and feel that it is really flying well. The airplane takes subtle mixing which takes a bit to get right.
I set the CG to the recommended 130mm and haven’t changed it. I also have stock incidence. I have down elevator with low throttle for downlines.
Knife Edge is fantastic. I have zero mix on right KE. It pulls very, very slightly on left KE and also has a very slight adverse roll so I use small elev and ail mixes to correct that.
There is some rudder mixing with throttle bit this is very slight as well. It is hard to get that just right due to the small amount required.
I think I have it tuned in pretty well. Don’t be afraid of mixing on this airplane. It responds very well with no weird behaviors.
The XDrive is really performing well. The BJ Force motor is very different than the similar sized Kontronik 650-53L. I compared them side by side in my drive unit. The BJ motor has a better throttle response and more low end torque. The Kontronik pulls more amperage in my setup than the BJ motor. Funny, the Kontronik runs much cooler than the BJ Force motor even though it consumes more power.
I have been out of action due to weather and other events but look forward to getting more air time. Hopefully the rains will let up.
Sorry for the lag in updating. But I have been flying the Eternity and XDrive and feel that it is really flying well. The airplane takes subtle mixing which takes a bit to get right.
I set the CG to the recommended 130mm and haven’t changed it. I also have stock incidence. I have down elevator with low throttle for downlines.
Knife Edge is fantastic. I have zero mix on right KE. It pulls very, very slightly on left KE and also has a very slight adverse roll so I use small elev and ail mixes to correct that.
There is some rudder mixing with throttle bit this is very slight as well. It is hard to get that just right due to the small amount required.
I think I have it tuned in pretty well. Don’t be afraid of mixing on this airplane. It responds very well with no weird behaviors.
The XDrive is really performing well. The BJ Force motor is very different than the similar sized Kontronik 650-53L. I compared them side by side in my drive unit. The BJ motor has a better throttle response and more low end torque. The Kontronik pulls more amperage in my setup than the BJ motor. Funny, the Kontronik runs much cooler than the BJ Force motor even though it consumes more power.
I have been out of action due to weather and other events but look forward to getting more air time. Hopefully the rains will let up.
02-09-2019, 05:06 PM
#66
One other note
B.J. Recommends mounting the props so that they line up on a 45 degree line rather than on a horizontal line. This eliminates some of the beat freq sound and also seems to smooth it out in flight. Maybe others with similar locked drive systems like Adverrun already do this. I didn’t do that on my Adverrun powered Agenda but I think it would be worth a try.
B.J. Recommends mounting the props so that they line up on a 45 degree line rather than on a horizontal line. This eliminates some of the beat freq sound and also seems to smooth it out in flight. Maybe others with similar locked drive systems like Adverrun already do this. I didn’t do that on my Adverrun powered Agenda but I think it would be worth a try.
02-11-2019, 10:37 AM
#70
I finally received mine. There were no notes or instructions provided with the model. You've already provided me with your CG location (thanks!). How about control surface throws for the first flight, especially the flying stab. Might you know the throws you're using? Also, is it just Velcro that's adhering your ESC and backup battery to the fuselage sides (i.e., no straps of any kind)? One other thing, did a tail wheel assembly come with yours? Thanks.
Mike
Mike
02-11-2019, 02:49 PM
#71
Hi Mike
Check post #47 in this thread for info on the Tail Wheel I used. There was one supplied but I have never liked the stock BJ Craft tailwheel. I really like that super light one from F3AUnlimited
As for Throws etc. Here's info from B.J. that I used in setting mine up initially (it is in Futaba Speak and refers to Futaba horns and settings):
Rudder servo horn: 40mm FUTABA big round horn. if the arm is too long the Rudder will always over shoot !
> (40mm Small horn + AFR 130% EXP 70% is good/ SNAP AFR 50% EXP 0%)
> 171 servo is too fast for rudder (0.19/sec is best) . AFR Speed, SIM Type / IN 3-7% OUT 1-2%
> AIL : Futaba + type horn, end hole. Normal 40% AFR, Set EXP 25% /SNAP 120% EXP 0%
> ELE : Futaba 6 arm type horn, end hole. normal 80% AFR, Set EXP 15% / SNAP Same.
Check post #47 in this thread for info on the Tail Wheel I used. There was one supplied but I have never liked the stock BJ Craft tailwheel. I really like that super light one from F3AUnlimited
As for Throws etc. Here's info from B.J. that I used in setting mine up initially (it is in Futaba Speak and refers to Futaba horns and settings):
Rudder servo horn: 40mm FUTABA big round horn. if the arm is too long the Rudder will always over shoot !
> (40mm Small horn + AFR 130% EXP 70% is good/ SNAP AFR 50% EXP 0%)
> 171 servo is too fast for rudder (0.19/sec is best) . AFR Speed, SIM Type / IN 3-7% OUT 1-2%
> AIL : Futaba + type horn, end hole. Normal 40% AFR, Set EXP 25% /SNAP 120% EXP 0%
> ELE : Futaba 6 arm type horn, end hole. normal 80% AFR, Set EXP 15% / SNAP Same.
02-11-2019, 10:17 PM
#74
By the way:
yes, the photos show the battery and ESC velcro’d on. The battery will probably stay that way. I waited on the ESC to make sure I had it in the right spot and it didn’t get in the way of battery access, also I wanted to make sure the CG was right. I have a small plate to mount it to with a velcro strap. I may put that in going forward but velcro works fine as long as you don’t keep removing the ESC and you keep changing the velcro out over time.
yes, the photos show the battery and ESC velcro’d on. The battery will probably stay that way. I waited on the ESC to make sure I had it in the right spot and it didn’t get in the way of battery access, also I wanted to make sure the CG was right. I have a small plate to mount it to with a velcro strap. I may put that in going forward but velcro works fine as long as you don’t keep removing the ESC and you keep changing the velcro out over time.
02-17-2019, 09:52 AM
#75
My Feedback: (41)
Guys, I have two available Eternity Biplanes that will arrive in about one week as well as three of the new BJ Craft Super Passion Bipes. (basically the same fuse as the Eternity different flying surfaces)
The Eternity's available are one ARF and one ARC.
https://www.f3aunlimited.com/bj-craf...ty-f3a-biplane
ARC:
https://www.f3aunlimited.com/bj-craf...ering-or-paint
I only have one of each for now.
This is the SP Passion new design.
All planes are easily converted from a Contra drive to a single upon request:
https://www.f3aunlimited.com/bj-craf...on-f3a-biplane
Thanks for looking and thanks to all my customers who allow us to bring these very exciting products to market.
Mike Mueller
The Eternity's available are one ARF and one ARC.
https://www.f3aunlimited.com/bj-craf...ty-f3a-biplane
ARC:
https://www.f3aunlimited.com/bj-craf...ering-or-paint
I only have one of each for now.
This is the SP Passion new design.
All planes are easily converted from a Contra drive to a single upon request:
https://www.f3aunlimited.com/bj-craf...on-f3a-biplane
Thanks for looking and thanks to all my customers who allow us to bring these very exciting products to market.
Mike Mueller