underdw

My Feedback: (2)

I had 2 collars with set screws in my kit that I believe were intended to go on either side of the center support to keep the tube from shifting laterally. Gary's way should work too (and be lighter).
You might want to wick thin CA into the wooden "hooks" on the canopy to harden them up. (I didn't have a problem, just thought it seemed like a good idea)

grotow

I am having a difficult time measuring the wing incidence relative to the thrust line. My only other experience with adjustable wing incidence was relative to canopy line. Anybody have a simple method of taking a incidence measurement relative to thrust line ( which should be +.5 degrees in this case)?

Thanks,
Gary

underdw

My Feedback: (2)

Hi Gary,
If you have a flat workbench, try this technique:
Construct a "fake prop" from a straight piece of 1x3" lumber. You need a center hole to clear the contra drive shaft and six clearance holes for the screw heads that hold the drive together. Holes can be oversized and crude, you just need to be sure that the wood gets clamped well to the contra spinner back plate.
So, remove the props from your contra and replace the rear prop with the fake prop.


Now set the plane up on your workbench using a carpenter's square to align the fake prop perpendicular to the workbench. Then measure points at the wing LE and TE for their distance from your workbench. Be careful to choose points that are equal-distant from the fuse centerline (not the fuse side), otherwise the dihedral will corrupt your measurement. Use trig to calculate the wing incidence: angle=arctan((LE-TE)/L)), where L is the chord length at your measurement location.
BJ has specified that the correct incidence is +2.5deg relative to the thrust line.

A conventional incidence meter and a bubble level can also be used if you trust the relationship between the bubble level's vertical measurement and the incidence meter's horizontal measurement.

Hope that helps. Let me know if I haven't written clearly.
Dan

grotow

Dan,
It is the incidence reading of +2.5 that was confusing me. I thought the reading should have been +.5 deg and I was reading +1 deg with the original (incorrect) anti rotation location. The fix of lowering rear pin and thus increasing the incidence by 1.5 deg will bring the reading to +2.5deg as you suggest. I took my readings my positioning the fuselage such that the nose was vertical with digital level and then took conventional incidence reading with same digital level. Does that sound OK to you? Gary

HerbK

Here is the way the canopy hold down is set up on my Inspire. I used piano wire through carbon fiber tube and left the wire exposed in the middle under the screws so it would spring forward to release the canopy.

pippy

Thanks for the photo Herb. The arrangement for this is different with the new kits. There is a wooden piece with a hole for the tube to go through but the plastic tube is quite loose and will require some method of tightening. Some have used glue and others collets. I will decide something between the 2.

underdw

My Feedback: (2)

Perfect Gary! That's the way to do it if you haven't mounted the contra yet.

grotow

Dan,

I am still not clear about that +2.5 deg incidence. Have you had any direct communication with BJ since his original email concerning the misplacement of anti-rotation pins? That email did state that correct settings are 2 deg down thrust and +0.5 wing incidence. Any input would be appreciated.

Thanks,
Gary

HerbK

Gary,
I think you should make this simpler on yourself and match the contra drive thrust setting to the nose of the plane. Then I would correct the antirotation pin locations to match up to BJ's diagram as a starting point. Install your adjusters so you can move up and down from there if you need to. Incidence settings and correcting KE depend a lot on where you like your CG. Another factor in Dan's case is that he is flying in Denver which is at 5,000 plus feet. BJ has made it very clear that this has a significant affect on the lift and yaw stability of the plane so what is good for Dan may not work for you. I would then go out and fly the plane as it flies very well at the factory settings with the correction BJ has made. You can then see what you need and go from there. Attached is a picture of my Inspire taking off.
Herb

pippy

Am I right to assume that I only use 4 of the White rubber grommets to set up the mount. The kit came with 8 (4spares).

underdw

My Feedback: (2)

That's what I did.

pippy

Is the spacer shown above on the Biside tail construction also to be used with the inspire? They didn't come with my kit so should I make up some. Can anyone tell me what thickness they should be please. I presume thy are used to ensure the all moving tail moves very freely.

HerbK

I used spacers on mine. I bought a few different thickness nylon flat washers to get the right fit that allows the stab to be snug against the fuse and move up and down properly.I use the spacers on both the front and back tubes. On the front tube I sanded the fuse a little so that the front washer moves smoothly as the stab moves up and down. The flying stab is a large surface and the spacers strengthen the whole thing.

Herb

grotow

The following line appears in the fix BJ posted on his website: "In your maiden flight fly the plane with fixed rear anti-rotation pin first, after that if the flight setting is finished,
fix 2 pieces of anti-rotation pin front and behind the main wing tube". Can someone please explain what he is saying?

Thanks,
Gary

HerbK

Gary,
He is saying to fly the plane with only the rear anti-rotation carbon fiber tube installed in the position BJ has in the diagram. After test flying and adjusting the rear anti rotation tube to get the incidence where you want it or very close install the front anti rotation pins with the adjusters. I used adjusters on both the front and rear pins. When I received the prototype from BJ he only had the rear tube installed with adjusters. I would not do snaps without both front and rear anti-rotation pins installed. I was able to test that there was no rolling or knife edge pitch depending on CG.Hopefully with the suggested position from BJ there should not be much additional incidence adjustment needed.
Herb

grotow

Herb,
Thanks for the explanation. Also, you posted a photo of elevator deflection. Is that 4 deg?

Gary

HerbK

Gary,
I think in normal flying full deflection is around 8 on the TX. I do use 30% Expo with the full stab as I fly with a very soft elevator. BJ says that with the flying stab you don't need much Expo at all but I think it is too sensitive with no Expo. I have a landing condition that has more elevator as well as for spin entry. I'll post a video of the Inspire flying the Master's pattern in a week or so.
Herb

grotow

Herb,
I am not familiar with all the shorthand terminology. I know TX usually is short for transmitter. What does "8 on the TX" represent?

Thanks,
Gary

HerbK

Hi Gary,
Sorry for the shorthand. Yes TX is transmitter and 8 is 8 degrees full throw in normal condition. Since I did the measurement in the picture I added a Elevator on Elevator dual rate to boost the end of the curve. I found that with the soft elevator there were times I needed a little more throw like at the bottom of the hourglass in masters and p sequence.
Herb

grotow

Help! I need to place my batteries completely forward of landing gear to balance on wing tube bulkhead. The rear servos are 64 gm each. Any suggestions would be greatly appreciated.

Gary

underdw

My Feedback: (2)

Hi Gary,
My 8411s are somewhat lighter than your servos I think(?). Shouldn't be a problem for overall weight, as this plane is VERY light.
Here is a pic of the battery/esc tray I constructed. ESC is mounted to the underside of the tray front. Tray mounts to some brackets I added onto the gear structure and to a rail I added up front (not visible in the pic). Multiple sets of holes allow me to shift the tray as I experimented with CGs. I'm using a more rearward CG than Herb (as partial compensation for flying at high altitude) and my lightest batteries (Power Unlimited 5100s at 590gm) still are over the gear mount. However, you might find my tray concept useful.
Dan

grotow

Dan,
My plane weighs in at 4700gm with 1066gm batteries with some landing gear reinforcement and lower fuselage seam reinforcement. I see your batteries extend well past landing gear even with a more rearward CG. Perhaps too much weight was removed from nose of plane and in its place we need a heavier tray system. I see the holes in tray but cannot make out how you are securing tray to rails.
Gary

HerbK

Here is a picture of my Inspire with the battery in place. The CG is marked in the picture. I mount the battery tray using the landing gear block in front and a carbon tube to support the rear. I hold the battery tray in place with zip ties.The prototype is a bit heavier then the production planes as mine comes in at 4950 or so with APC props. I use carbon fiber props for competition and APC props for practice. I also reinforced the landing gear block with carbon fiber as shown in the picture. I use futaba BLS servos for Elev and Rudder which are a bit heavier then the one's you mentioned. I use the power unlimited batteries Dan mentioned as well as others that are similar weight
Herb.

Anthony-RCU

My Feedback: (2)

Gary
You have very light packs. Which are they? I have had similar issues using the Hobby People 4500 but need a very different location for my 5100 packs. Herb's look like 1200g packs so it is difficult to compare. Herb do you change pack location when you switch from the APC props to CF? That is about 90g difference very far from the CG.

grotow

Anthony
Hyperion 25C 4600.