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Old Jun 28, 2012, 05:12 PM
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bdelapen's Avatar
United States, FL, Pembroke Pines
Joined Aug 2008
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Quote:
Originally Posted by ALL American View Post
Hey guys,

I just put together a vintage, COX electric powered sailplane with some modern upgrades including a brushless power system. I got the CG sorted out and the glide is good and it cruises along nice and slow at half throttle. The plane has an undercambered airfoil so by nature it climbs like a banshee when it picks up speed under power. Any throttle setting over 50% causes the plane to pitch up violently at 90 degrees or greater requiring down elevator.

A throttle to elevator program mix is easy enough to do but I'd like to set up a throttle to elevator program mix that doesn't start feeding in any down elevator until the throttle has exceeded 50%. Any suggestions?

Thanks in advance for any reply.

Anthony
You should be able to get what you want using a Pmix and if offsets don't work for what you want you can change it to a point curve. Let me know if you need more detailed setup instructions.

P.S. did you consider adding more down thrust?

- Birger
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Old Jun 28, 2012, 06:16 PM
Play tetris with my english
DaxFX's Avatar
Puerto Rico, San Juan
Joined May 2008
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Quote:
Originally Posted by ALL American View Post
Hey guys,

I just put together a vintage, COX electric powered sailplane with some modern upgrades including a brushless power system. I got the CG sorted out and the glide is good and it cruises along nice and slow at half throttle. The plane has an undercambered airfoil so by nature it climbs like a banshee when it picks up speed under power. Any throttle setting over 50% causes the plane to pitch up violently at 90 degrees or greater requiring down elevator.

A throttle to elevator program mix is easy enough to do but I'd like to set up a throttle to elevator program mix that doesn't start feeding in any down elevator until the throttle has exceeded 50%. Any suggestions?

Thanks in advance for any reply.

Anthony
You can use the camber mix. You will be able to counteract the camber of the wing by raising or lowering all 4 wing surface control. You can set the cambermix to a slider switch in tx so you can use try by steps instead a fixed position. When you get the amount you need just setup to activate with throtle.

Or setup in a flight mode for speed

Using the elevator to throtle mix will also work but will create more drag,
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Last edited by DaxFX; Jun 28, 2012 at 06:22 PM.
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Old Jun 28, 2012, 06:25 PM
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bdelapen's Avatar
United States, FL, Pembroke Pines
Joined Aug 2008
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Quote:
Originally Posted by DaxFX View Post
You can use the camber mix. You will be able to counteract the camber of the wing by raising or lowering all 4 wing surface control. You can set the cambermix to a slider switch in tx so you can use try by steps instead a fixed position. When you get the amount you need just setup to activate with throtle.

Or setup in a flight mode for speed

Using the elevator to throtle mix will also work but will create more drag,
I'm going to hazard a wild guess that there are no ailerons or flaps on that plane. .

- Birger
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Old Jun 28, 2012, 09:14 PM
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vespa's Avatar
Thousand Oaks, CA
Joined Mar 2004
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Yeah, tough to mold a 4 servo wing out of a single piece of plastic. Besides, you can't make any mixes with camber. It's a bug.
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Old Jun 29, 2012, 05:42 AM
Registered User
Brighton UK
Joined Dec 2010
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Quote:
Originally Posted by ALL American View Post
Hey guys,

A throttle to elevator program mix is easy enough to do but I'd like to set up a throttle to elevator program mix that doesn't start feeding in any down elevator until the throttle has exceeded 50%. Any suggestions?

Thanks in advance for any reply.

Anthony
As always, the 8FG provides many options but your suggestion of a program mix will work fine so why complicate matters?

In its default setting a throttle to elevator mix will give zero elevator deflection when the throttle stick is in the 50% position. The two values at the top of screen 1/2 of the program mix determine how much the elevator will move when the throttle stick is moved down towards low throttle and up towards high throttle. Accordingly, if you simply leave the top value at zero and set the lower one to the amount of elevator you require, the mix will only take effect once the throttle stick moves above its 50% position. In the first picture the elevator will begin to move once the stick is pushed above the 50% position and will reach 30% travel when the stick is at the full throttle position.

If you want to change the point at which the throttle stick begins to move the elevator you can do so by changing the X offset value. Entering a minus value will cause the elevator to start moving when the stick is below the mid position and a positive value will delay the start of movement until the stick is above the mid position. In the second picture the elevator will begin to respond when the throttle stick is three-quarters of the way up (50% offset from the middle).
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Old Jun 29, 2012, 12:34 PM
It's Not Too Windy...Man Up
ALL American's Avatar
USA, CT, Wallingford
Joined Oct 2009
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Quote:
Originally Posted by bdelapen View Post
You should be able to get what you want using a Pmix and if offsets don't work for what you want you can change it to a point curve. Let me know if you need more detailed setup instructions.

P.S. did you consider adding more down thrust?

- Birger
Thank you for the reply Birger. The CG is good and the down thrust is fine if I fly the plane at speeds the manufacturer designed the aircraft to fly. The brushless setup provides about 13 Mph (28% more speed) more pitch speed than the original brushed / geared power system and undercambered wings tend to offer a lot of lift at higher speeds. Therefore, a program mix is best in this case.

Regards,
Anthony



Quote:
Originally Posted by DaxFX View Post
You can use the camber mix. You will be able to counteract the camber of the wing by raising or lowering all 4 wing surface control. You can set the cambermix to a slider switch in tx so you can use try by steps instead a fixed position. When you get the amount you need just setup to activate with throtle.

Or setup in a flight mode for speed

Using the elevator to throtle mix will also work but will create more drag,

Thanks for the reply! It's a vintage three channel aircraft with no control surfaces on the wing.

Regards,
Anthony


Quote:
Originally Posted by MalcolmHolt View Post
As always, the 8FG provides many options but your suggestion of a program mix will work fine so why complicate matters?

In its default setting a throttle to elevator mix will give zero elevator deflection when the throttle stick is in the 50% position. The two values at the top of screen 1/2 of the program mix determine how much the elevator will move when the throttle stick is moved down towards low throttle and up towards high throttle. Accordingly, if you simply leave the top value at zero and set the lower one to the amount of elevator you require, the mix will only take effect once the throttle stick moves above its 50% position. In the first picture the elevator will begin to move once the stick is pushed above the 50% position and will reach 30% travel when the stick is at the full throttle position.

If you want to change the point at which the throttle stick begins to move the elevator you can do so by changing the X offset value. Entering a minus value will cause the elevator to start moving when the stick is below the mid position and a positive value will delay the start of movement until the stick is above the mid position. In the second picture the elevator will begin to respond when the throttle stick is three-quarters of the way up (50% offset from the middle).

Malcolm,

As usual, you have filled in all of the blanks regarding programming this radio. Thank you for the reply and explanation of the offsets. It's all set up and ready for a test flight. I'll let you know how it worked out.

Best Regards,

Anthony
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Old Jun 30, 2012, 05:09 PM
3d Kiwi
uptime4downtime's Avatar
New Zealand
Joined Dec 2007
3,113 Posts
Hi all

What is the best way to back up my models? I'm guessing my models are all stored on the TX at present, but is there a way to copy these to the card to backup? I notice the copy menu, but I can't for the life of me quite figure what to do with it.

Thanks
(just popped a screen protector on mine - i notice that the metal toggle fastener was slowly making semicirular marks across the screen)
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Old Jun 30, 2012, 05:31 PM
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bdelapen's Avatar
United States, FL, Pembroke Pines
Joined Aug 2008
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Originally Posted by Rick662u View Post
Hi all

What is the best way to back up my models? I'm guessing my models are all stored on the TX at present, but is there a way to copy these to the card to backup? I notice the copy menu, but I can't for the life of me quite figure what to do with it.

Thanks
(just popped a screen protector on mine - i notice that the metal toggle fastener was slowly making semicirular marks across the screen)
Pop an SD card int it if you haven't yet, the radio will ask you and then format it automatically if it is not already the right format. Note that the card can be max 2GB, none of the newer high speed and high capacity cards will work so look into your old digital camera for one. Also, it has been noted that although most small cards will work there is a few that just don't.

Once the card is in place and formatted correctly you can then copy each model individually to the card. Turn off the transmitter, pop the card out and head over to your PC equipped with an SD card reader and pop it in.

Use the "File System Utility" found in this page to read the contents of the card and now you can back up your models to your PC (and any additional media you want). Use the file system utility again if you ever want to put them back.

One more thing, you can use the models directly from the card if you want, you will however notice that the card is considerably slower to load and write than the internal memory so I would discourage any serious programming directly to the card, it will get frustrating.

- Birger
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Old Jun 30, 2012, 06:12 PM
3d Kiwi
uptime4downtime's Avatar
New Zealand
Joined Dec 2007
3,113 Posts
Thank you very much.

I'm still a bit stuck on how to back up or copy to the card. Is there a special menu for this? No problem, I'll probably figure it out. Just don't want to loose anything in the process.
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Old Jun 30, 2012, 06:26 PM
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bdelapen's Avatar
United States, FL, Pembroke Pines
Joined Aug 2008
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Quote:
Originally Posted by Rick662u View Post
Thank you very much.

I'm still a bit stuck on how to back up or copy to the card. Is there a special menu for this? No problem, I'll probably figure it out. Just don't want to loose anything in the process.
First of all, you won't loose anything unless you specifically delete or change the configuration of your airplane (model type, wing type, tail type, swashplate type).
  1. Select the model you want to copy (i.e. make it the active model)
  2. Go to the model select screen, you will have 5 models on the right and on the left you will have the tx/card selector and below it the copy menu.
  3. Select the copy option, pick the destination (card in this case) and then go through the "OK" process. (note, the radio will use the same name when copying tx/card or vice-versa, if the model already exists it will start adding sequential numbers).
  4. If you copy tx/tx and you already have 20 models it will ask you which one you want to replace, if it has space it will ask to add new I believe (i've been full for so long I can't remember, or test).

Hope this helps.

- Birger
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Old Jun 30, 2012, 06:27 PM
3d Kiwi
uptime4downtime's Avatar
New Zealand
Joined Dec 2007
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This is good of you. Found it after scrolling the tx symbol. Now it all makes sense. Great. Happy flying and thanks. Rick
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Old Jun 30, 2012, 09:09 PM
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United Kingdom, England, Brighton
Joined Jan 2012
1,762 Posts
Hi everyone

I was flying my Jart M70 today about 400ft away and started to loose connection. So I brought it lower and I was fine. Out of interest I took it higher and it started to loose connection again. I then to make sure my eyes weren't playing tricks on me wrapped my hand around the aerial and lost complete connection. Took my hand away again and was fine. I am using an 8FG and r6008hs receiver

So because of this, my questions are:

I was standing in front of a bush, would this hinder signal?

My aerial was erect pointing upwards. Is this the best position (I've always assumed it was )?

My glider fuse is fibreglass so shouldn't be a problem. But will putting the aerials externally help?

One of my aerials goes forward and the other back, is this ok? It's hard to achieve that 90 degree stuff in my glider, hehe!

Thanks!
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Old Jun 30, 2012, 09:14 PM
3d Kiwi
uptime4downtime's Avatar
New Zealand
Joined Dec 2007
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First thing I'd try is a range check on the ground in the exact same location and see what occurs. Very strange... I would almost suspect the RX, TX, - what other RX do you use, age of TX, etc would be interesting to know
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Old Jun 30, 2012, 10:34 PM
Registered User
DeBary, FL
Joined Nov 2010
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Quote:
Originally Posted by RCPilot1234 View Post
Hi everyone I was flying my Jart M70 today about 400ft away and started to loose connection. I am using an 8FG and r6008hs receiver

I was standing in front of a bush, would this hinder signal?
Maybe, if it's a synthetic Xmas tree. Well, not block-hinder, but it might reflect/refract the signal weirdly.

Quote:
My aerial was erect pointing upwards. Is this the best position (I've always assumed it was )?
Directly -at- the receiver is the worst. Straight up is fine if the plane is somewhere in front of you. But even if it's straight up over your head, that generally means you have to lean back to see it, and the antenna is probably not pointed at it.

Quote:
My glider fuse is fibreglass so shouldn't be a problem. But will putting the aerials externally help?
Not a problem, fiberglass is electrically 'inert.'

Quote:
One of my aerials goes forward and the other back, is this ok? It's hard to achieve that 90 degree stuff in my glider, hehe!
This may be the source of your blackouts because the two leads directly inline leave a 'blind spot' (actually two blind spots) when the ends are pointed either directly at or away from you.

The fix isn't difficult even in a skinny glider fuse. Obviously there's no way the full-90deg can be achieved in most avg-smaller fuses. But it's actually the last uninsulated 1" of each antenna lead that's 'most important.' The long leads are to simply have a better chance that the lead ends not be blocked by, for instance, a large ESC. If you bend one lead -end- up 45deg, just the last 1" and the other down 45deg (or one left and one right) then you have achieved the preferred 90deg angle. Look closely at the pics in the 8fg manual and you'll see that effect.

'Bend' meaning a curve no smaller than about a pencil or a dime diameter.
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Old Jun 30, 2012, 10:49 PM
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vespa's Avatar
Thousand Oaks, CA
Joined Mar 2004
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You shouldn't lose signal with a dual antenna rx in a little plane like the Jart. Either your rx antennas are broken or very shrouded in something conductive. Tape the two cables together in an X shape and stuff them somewhere far away from batteries, servos, wires, pushrods, etc.

Also use a flashlight to verify that your fuselage is not carbon in that region. If you can't see light it's carbon.
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