HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Feb 13, 2010, 10:35 PM
Registered User
United States, HI, Pearl City
Joined Aug 2006
315 Posts
Paint Scheme

Playing around with the paint scheme to get the best visibility at altitude while maintaining orientation. My first idea is to paint the top so I can better orientate the plane while circling. With that in mind, I drew a few sample paint schemes for the top. I noticed that a large yellow strip on the tip was still the best when the paint schemes were zoomed really small with my graphics program. I don't know if this would be the same as in real life, but I think the idea is correct. Here are the paint schemes and the original file (svg format). The bottom two paint schemes in the picture seem to work best. Next, I'll look into adding a strip on the bottom of the wing.

Scotty
wsmorton is online now Find More Posts by wsmorton
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 08, 2010, 10:45 PM
Registered User
United States, HI, Pearl City
Joined Aug 2006
315 Posts
Flap Servos

I am re-doing the flap linkage. The old setup (with the servo shaft towards the trailing edge) just isn't giving me the throw that I want. But mostly, there's a little more slop than I would like.

But first: I am using the Hyperion Digital DS13 TMB servos and programed them for max throw. I made some custom servo frames that allow easy servo install and removal. Each frame weighed in at 5 grams. I used two brass tubes to hold the servo in place. They are sized to be a perfect fit with the holes in the servo tabs. Two brass tubes are used. One brass tube fits inside the other to provide a stronger setup. Servo install and removal is a sinch! Just slide the servo off of the brass tube. Just be sure you have enough room in the servo well to slide the servo out. I think I could shave another gram by using only one stainless steel tube per side, but I couldn't find any at the local stores. And by using a bit less epoxy. Next time. :>)

I'll post a video of the install when I get the chance.


Scotty
wsmorton is online now Find More Posts by wsmorton
Reply With Quote
Old Mar 09, 2010, 05:15 AM
Skye Malcolm
skye8070's Avatar
Upper Arlington, OH
Joined Mar 2009
644 Posts
Remember when I said 70 degrees of flap throw? Yeah, maybe not so much

Scotty
I just flew on Sunday down in Cincinnati with the Eraser. It flew well, I did not. So I've got it on the couch right now tuning out the up elevator with camber compensation because it stalls and there's a couple of sources (my buddy and the radio carbon arts dvds) saying that slight down elevator might actually be better with camber.

Anyway, that's not the point of this post - I want you to look at the two attached pictures which show neutral flaps lined up with the fixed part of the wing near the fuse and then "full" flaps with my servos and radio. I recall having to tune down one of the servos to compensate for the other getting noisy at extreme full flaps and this is the result. In fact I've been flying like this since a contest in September (at least) and it lands just fine for me. Clearly this is no 70 degrees flap. More like 45. The exact number isn't too important, just the point that you might want to get a rock solid linkage to the servo and then not worry about extreme throws if it doesn't work out easily for you. Also I see my flaps are driven from the top (f3j/euro style) and not as yours appear to be, so my setup might be more restricted than yours.
skye8070 is offline Find More Posts by skye8070
Reply With Quote
Old Mar 09, 2010, 08:58 PM
Registered User
United States, HI, Pearl City
Joined Aug 2006
315 Posts
That slop in the old setup was my main concern. One of the flaps started to flutter on approach and scared be a bit. So, I just experimented with several different linkage configurations until I came up with something that seemed really tight. I also upgraded the linkage to 4-40 rods and links. Then I looked at how to maximize the throw. Since the linkage is on the bottom of the wing and I didn't want to cut into the wing skin to allow for more movement, I kind-of limited myself. I wasn't too worried about getting 70 degrees or more out of it, I just had that engineer in me kick in. To increase the servo throw, I setup a program mix on my 9303 transmitter that helped to increase the servo throw. I also figured, I might as well grind some of the metal off of the linkage at the servo end to allow for just a bit more throw. The setup allows for a nearly slop free setup at 0 flaps and full flaps. It's a definite improvement over the previous setup. I'll see how it holds up this weekend. I may try moving the linkage in toward the servo shaft by one more hole on the servo horn, if this setup doesn't work out.

That flap throw you have looks like about 45 degrees. That should be plenty to slow the plane down for landing. I think anything past this amount just causes more drag without increasing lift. I might try some experiments with this setting.

I've seen the stall thing with camber on the Onyx that I fly. When I kick in the camber (in thermal mode) the plane noses up a fair amount. I don't have any elevator compensation mixed in the thermal mode and if I wasn't careful, the plane would stall with too much elevator input. Now I'm thinking I should go back and add in some down elevator like what you are doing. I haven't flown the Eraser enough to use the camber yet, but most likely, I'll add in the compensation on the Eraser as well.

I got the video posted at YouTube for the servo install and removal:
Removing Servo:
Removing Servo (0 min 10 sec)

Installing Servo:
Installing Servo (0 min 12 sec)


Scotty
wsmorton is online now Find More Posts by wsmorton
Reply With Quote
Old Mar 09, 2010, 09:37 PM
Skye Malcolm
skye8070's Avatar
Upper Arlington, OH
Joined Mar 2009
644 Posts
Quote:
Originally Posted by wsmorton View Post
...

I've seen the stall thing with camber on the Onyx that I fly. When I kick in the camber (in thermal mode) the plane noses up a fair amount. I don't have any elevator compensation mixed in the thermal mode and if I wasn't careful, the plane would stall with too much elevator input. Now I'm thinking I should go back and add in some down elevator like what you are doing. I haven't flown the Eraser enough to use the camber yet, but most likely, I'll add in the compensation on the Eraser as well.

Scotty
I had up elevator mixed to the camber slider on the SD10G and then I have a "float" flight mode selectable from a 3 position switch. The thing is the slider would put in up elevator compensation but the float mode switch really just did camber to a set position with only a fraction of the up elevator compensation with the slider.

Turns out using the slider would stall the snot out of the plane and using the switch was "OK". Not great, just OK. Knowing that info, I reprogrammed the slider to have zero elevator compensation. Thinking about it now I could try slight down elevator compensation for one of the flight modes and just no compensation for the other flight mode so I could get a feeling for the difference in-flight. I have not flown yet with these changes but I'll keep you posted for sure.

Even with the questionable elevator compensation this plane literally bounds upwards towards the clouds with camber vs. clean wing (lined up with the fixed portion). Talking to one of the experienced guys there he said the MH-32 airfoil responds well to camber.

Bottom line is that I still have a ton more flying and tuning up of the plane before I get a better feeling for it's ins and outs.
-Skye
skye8070 is offline Find More Posts by skye8070
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log Easy Glider AP/AV Re-Build!!! Flipper_118 Aerial Photography 123 Mar 05, 2010 10:29 PM
Build Log Re-Build Log - Vintage Slegers Skyhawk - 3 Meter Thermal Rotozuk Electric Sailplanes 9 Oct 08, 2009 01:17 AM
Discussion Time for a re-build Bothersome Fuel Heli Talk 2 Aug 24, 2009 05:58 PM