How to Determine Engine Placement?
06-30-2017, 11:44 AM
#26
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Hello,
it it looks great Z-trap. I would expect it to fly very well. It has a little more power than is necessary so it shoulb be able to climb and most maneuvers like loops,rolls, snaps etc at half throttle. Trim it out and enjoy it. If you can fly a trainer then you can fly this one. One of my favorite maneuvers was a 25' leg square loop beginning at 10 ft altitude. Let us know how it goes.
james
it it looks great Z-trap. I would expect it to fly very well. It has a little more power than is necessary so it shoulb be able to climb and most maneuvers like loops,rolls, snaps etc at half throttle. Trim it out and enjoy it. If you can fly a trainer then you can fly this one. One of my favorite maneuvers was a 25' leg square loop beginning at 10 ft altitude. Let us know how it goes.
james
07-10-2017, 07:26 PM
#27
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Maiden Flight Report and Video!!
Ladies and gentlemen: we have F L I G T of the Dust Devil! After sitting as a box of wood since 1999, the "Beast" took flight yesterday, Sunday July 9th. Late in the afternoon, around 4 pm, we had 5-10 MPH winds from the west and temp around 85 - clear skys and excellent visibility. The plane handled very well on the ground. It ran down the runway a few times, and the tail came up every time ... I could tell it wanted to fly.
Take off run was predictable and smooth. Tail came up, as expected. With a touch, and I mean a touch of up elevator it literally jumped into the air. The instructions did say that "up elevator" is sensitive, and they are right. First right turn was smooth, and the plane leveled-off well. Very surprisingly, no trim was applied or needed. The plane tracked straight and true, and was very well behaved and smooth throughout the first few turns. At the 5 minute mark, the nose was pointed into the wind and the engine was throttled down to ready the Dust Devil for the landing approach. The glide path was smooth, and maybe a little too slow. You can see from the video a subtle stall in the last few seconds caused a bit of bouncy landing ... I'll need some more practice with this plane to get used to managing the speed and a good flare at the end. Overall, a satisfying day.
My daughter put together a nice video that is posted on YouTube. The link is attached. Thanks for all the feedback through the build ... I truly appreciated the insights.
Good flying all!
Z-Trap
Take off run was predictable and smooth. Tail came up, as expected. With a touch, and I mean a touch of up elevator it literally jumped into the air. The instructions did say that "up elevator" is sensitive, and they are right. First right turn was smooth, and the plane leveled-off well. Very surprisingly, no trim was applied or needed. The plane tracked straight and true, and was very well behaved and smooth throughout the first few turns. At the 5 minute mark, the nose was pointed into the wind and the engine was throttled down to ready the Dust Devil for the landing approach. The glide path was smooth, and maybe a little too slow. You can see from the video a subtle stall in the last few seconds caused a bit of bouncy landing ... I'll need some more practice with this plane to get used to managing the speed and a good flare at the end. Overall, a satisfying day.
My daughter put together a nice video that is posted on YouTube. The link is attached. Thanks for all the feedback through the build ... I truly appreciated the insights.
Good flying all!
Z-Trap
07-11-2017, 07:06 AM
#28
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In case anyone is interested in building one, the plans and instruction booklet can be found here: https://aerofred.com/details.php?ima...57&mode=search
I'm glad to answer any questions.
Z-Trap
https://aerofred.com/details.php?ima...57&mode=search
I'm glad to answer any questions.
Z-Trap
https://aerofred.com/details.php?ima...57&mode=search
07-14-2017, 07:02 AM
#29
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OK - made a couple changes for the next field outing:
1) Added 30% and 50% exponential movement in the elevator channel to 'tame' the inherent sensitivity - hopefully less jumpy take-offs and landings
2) Added "two clicks down elevator"
3) Changed out the 4" very stiff DuBro wheels with 5" Sullivan SkyLines for smoother ground handling on bumpy grass. I wish DuBro made their light weight (hollow) treaded wheels in larger sizes. Not a fan of the stiff solid foam - just too hard.
4) Moved some weight (battery) a little aft to bring CG point near its center. I'm certain it was on the nose heavy side.
1) Added 30% and 50% exponential movement in the elevator channel to 'tame' the inherent sensitivity - hopefully less jumpy take-offs and landings
2) Added "two clicks down elevator"
3) Changed out the 4" very stiff DuBro wheels with 5" Sullivan SkyLines for smoother ground handling on bumpy grass. I wish DuBro made their light weight (hollow) treaded wheels in larger sizes. Not a fan of the stiff solid foam - just too hard.
4) Moved some weight (battery) a little aft to bring CG point near its center. I'm certain it was on the nose heavy side.
07-14-2017, 05:12 PM
#30
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I saw this thread a few weeks ago and it brought back some good memories. I built one in 1999 and loved it. A friend of mine built one in 2000 while going thru chemo for prostate cancer ( that he beat and has no other problems to this day). I sold mine after a few years and have regretted it every since. My friend stoped flying in 2010 and it has been in his rafters every since. He gave it to me and with a lot of cleaning and new engine I flew it today I forgot just how fun this plane is. The VVRC 20 is a perfect match. Now just to figure out what to do about a cowl the old one was so bad there was no fixing it.
07-14-2017, 05:53 PM
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IIMAC - So great to read your post, see the picture, and to know your friend is doing well. And best of all, you have another Dust Devil to fly. I'll look into that VVRC-20, I heard lots of great things. As far as the cowl is concerned, I wonder how I can make a mold for you from my cowl ... any ideas? I'd be glad to help. There must be some sort of 3D imaging CAD thing that would make the process or reproducing the cowl easier.
Last edited by ZTrap; 07-14-2017 at 06:02 PM.
07-17-2017, 10:57 AM
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Quick report on the applied adjustments, and this weekend's flights ...
- The exponential made a significant positive difference, and at 50% exponential in the elevator movement the plane was smooth as silk on take-offs and landings - this was desperately needed and tamed the sensitivity of the elevator leading to "jumpy" movements
- Keeping to the exact CG, and eliminating the "nose heavy" orientation for the maiden flight was also needed. Recommend to balance to the CG from the start.
- The 5" Sullivan wheels is the way to go with this plane - ground handling couldn't be better.
- The plane is using a 1 degree right, and 1 degree down thrust.
- I would recommend a 'side-monted' engine for anyone building the plane with 2S or 4S glow engines. The inverted orientation doesn't leave a lot of room to center the tank with the carburetor - very tight fit, and it doesn't have to be.
03-25-2019, 04:38 PM
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Unfortunately I bought mine built by another person so I don't have the instruction booklet or the CG I balanced mine at the spar and it seems to fly real nice. One thing I do remember is you build the wing to the size of the wood not the plans. In other words the sheer webs set the wing ribs which might be slightly off from the plans. Have fun it's a great airplane.
