Help with CCPM upgrade

[Aussie newbie]

Hi everyone,

I recently purchased the CCPM upgrade for my X400. It went together reasonably well but I am having trouble with my pitch range. I am using a JR XP662 radio. In the swash mixing I have pitch, aileron and elevator all at 80% but I am still only getting a maximum of 7 degrees positive and negative pitch.

With my stock mechanical mixing setup I was able to able to hover just above half stick. Now with my CCPM uprade it will not hover until half way between 3/4 and full stick. I was thinking that I may have all my linkage lengths messed up. Does anyone have any suggestions?

Thanks.

[fedex]

I just ordered one of these upgrades, did you get yours working right?

http://www.grandrc.com/inc/sdetail/12396

[Aussie newbie]

It is so much better than the stock mechanical mixing. I think you will be really happy with it. I think the problems I am having are not with the upgrade itself, but more me not knowing how to set up the links correctly. One thing I did notice though, is the servo horn on the elevator servo inerferes with the anti rotation guide.

[fedex]

Originally Posted by Aussie newbie

It is so much better than the stock mechanical mixing. I think you will be really happy with it. I think the problems I am having are not with the upgrade itself, but more me not knowing how to set up the links correctly. One thing I did notice though, is the servo horn on the elevator servo inerferes with the anti rotation guide.

I noticed that problem on the other thread. Can it be solved without moving the antirotation guide to the front like he did? just don't look very good. I really don't want to move the guide. I may wait on this upgrade even after I get the parts. It was the last one in stock, or so I think it was, so I figured I'd better order it. Can you take a picture of the problem and show me?

[Aussie newbie]

As you can see in the photo the servo arm hits on the bottom of the anti rotation guide. I was thinking about gringing off the end of the arm but I'm not sure if that will be enough. First I need to solve my problem of not enough pitch. Because I'm only getting 6 degrees at almost full throttle my flight time is considerably shortened and the battery is getting very hot compared to my previous setup with mechanical mixing.

Radio setup is as follows:

Swash mixing for pitch, aileron and elevator all 80%
Throttle curve (normal mode) 0, 50, 100
Pitch curve (normal mode) 30, 80, 100

One other question, should the balls on the servo arms be the same distance from the servo output shaft on all 3 cylclic servos? Currently they are all on the middle hole. Would it matter if I moved moved the ball on the elevator servo to the first hole?

[10karer]

I have the CCPM upgrade using hs65 servos and have no problem with the servo hitting the antirotation Guide. Ball Links are set at 11.5mm and I get +/- 11 deg of pitch

Dave

ps lok at the finless video on CCPM setup it is for the trex but still aplys as our Heli is so simmiler

[fedex]

Seems like a round servo horn would work if nothing else. I would try that. If you can get full deflection both ways, just enough to get your +10 -10 pitch thats good. I'm using hs65's as well, but the 55's should work fine, I think the servo horns are slightly different. On the 55's you prolly need to dremel the last hole off of the servo horn.

[fedex]

Originally Posted by Aussie newbie

As you can see in the photo the servo arm hits on the bottom of the anti rotation guide. I was thinking about gringing off the end of the arm but I'm not sure if that will be enough. First I need to solve my problem of not enough pitch. Because I'm only getting 6 degrees at almost full throttle my flight time is considerably shortened and the battery is getting very hot compared to my previous setup with mechanical mixing.

Radio setup is as follows:

Swash mixing for pitch, aileron and elevator all 80%
Throttle curve (normal mode) 0, 50, 100
Pitch curve (normal mode) 30, 80, 100

One other question, should the balls on the servo arms be the same distance from the servo output shaft on all 3 cylclic servos? Currently they are all on the middle hole. Would it matter if I moved moved the ball on the elevator servo to the first hole?

I think your pitch curves are supposed to be 0 25 50 75 100

[fedex]

Originally Posted by Aussie newbie

Hi everyone,

I recently purchased the CCPM upgrade for my X400. It went together reasonably well but I am having trouble with my pitch range. I am using a JR XP662 radio. In the swash mixing I have pitch, aileron and elevator all at 80% but I am still only getting a maximum of 7 degrees positive and negative pitch.

With my stock mechanical mixing setup I was able to able to hover just above half stick. Now with my CCPM uprade it will not hover until half way between 3/4 and full stick. I was thinking that I may have all my linkage lengths messed up. Does anyone have any suggestions?

Thanks.

From what I've read you should remove those extended balls, because the radius to the axis is different which causes involentary pitch movement when using fwd and aft elevator.

[darkside212]

You should definitely have the ball links in the same position on all of the servos that is probably why you're not getting the range you desire. I have my linkages set on the second hole from the end of the horn. If your pitch servo is hitting the antirotation bracket try clipping off the excess.

One thing I find REALLY helpful is to use a servo tester when setting up the heli. I have a dnpower servo tester (that I sell so I am biased) and it's default position is half of the servo's throw range. This allows me to set each servo and lenghten/shorten each linkage so the pitch is 0 at half of the servos throw.

After I do this I worry about the pitch settings on the tx. I personally don't use pitch guages as I find them more difficult (for me) to use. What I do is try certain setting that give me the full negative and full postive pitch that I need (I just eyeball this). I then divide that into equal intervals for five points on the tx (some tx's use 3 points).

After I have this I fly in normal mode with throttle curve of 0 25 50 75 100 and see how I like it. I then tweak the curve for idle up it is usually "lower settings" for the pitch curve because you don't need as much pitch if the rotors are spinning at full (or close to full) RPM.

I just got an MX450 XS with the ECCPM carbon frame and REALLY like it. It is a very smooth, and stable heli.

BTW for my swash arf settings I have these:

Pitch 50% even though I have it limited to 50% I'm not using that much of the curve so I could reduce it more to have an even more detailed pitch curve

Elevator 75%

aileron 75%


Hope this helps!
Paul

[Aussie newbie]

With your ball links on the second hole, how far in mm are the ball links from the servo output shaft. Also if you wouldn't mind could you tell me the lengths of your links from the servo to the swash plate. Just want to compare so I can see if I am reasonably close.

Thanks.

[darkside212]

Sure,
the ball links are about 15mm from the center of the servo to the center of the ball (screw to screw)

my two aileron rods are 45mm and 30mm
elevator is about 35mm

I measure these all center to center of the ball links

[fedex]

Originally Posted by darkside212

Sure,
the ball links are about 15mm from the center of the servo to the center of the ball (screw to screw)

my two aileron rods are 45mm and 30mm
elevator is about 35mm

I measure these all center to center of the ball links

I saw a post on trex tuning on these measurements.

http://www.trextuning.com/forums/showthread.php?t=4746

[Aussie newbie]

Thanks darkside212 & Fedex, just what I needed.

[fedex]

Originally Posted by Aussie newbie

Thanks darkside212 & Fedex, just what I needed.

Hows your mod coming? I just finished mine up today

[Aussie newbie]

My heli is starting to fly reasonably well now. I ground the end of the elevator servo arm and the underside of the antirotation bracket so there is no interaction now. Found a new problem to try and fix though. I am using HS55 servos and inorder to avoid the elevator servo arm hitting the antirotation bracket (even after grinding the end of the arm) I had to use the middle hole on the arm for the ball link. As a result the ball link is only 10mm from the servo output shaft. This does not give me a great deal of servo throw for collective pitch. Even with swash mixing for pitch at 85% I am still only getting 7 degrees of positive and negative pitch. There is no way I will get to my desired 12 degrees pitch without longer servo arms, but then I will be back where I started with the antiratation bracket interaction. Any suggestions?

[fedex]

Originally Posted by Aussie newbie

My heli is starting to fly reasonably well now. I ground the end of the elevator servo arm and the underside of the antirotation bracket so there is no interaction now. Found a new problem to try and fix though. I am using HS55 servos and inorder to avoid the elevator servo arm hitting the antirotation bracket (even after grinding the end of the arm) I had to use the middle hole on the arm for the ball link. As a result the ball link is only 10mm from the servo output shaft. This does not give me a great deal of servo throw for collective pitch. Even with swash mixing for pitch at 85% I am still only getting 7 degrees of positive and negative pitch. There is no way I will get to my desired 12 degrees pitch without longer servo arms, but then I will be back where I started with the antiratation bracket interaction. Any suggestions?

Well I'm getting alot of pitch, I can really crank it +14 degrees or more. I'm on the second hole of one of my larger 3d horns for the hs65 servos, I ground down the antirotation guide a good bit, to almost where the screw threads would show, It still needs a bit more, but it manages to clear. Are you increasing your pitch in the swash menu?

[Gizmo6035]

Hey Fedex,
any chance of a pic of your mod without having to disassemble anything?
I have the aluminum CCPM upgrade that I am about ready to install so your tips will be put to good use

Well I'm getting alot of pitch, I can really crank it +14 degrees or more.

is that total of pitch and cyclic or pitch only?

[fedex]

Originally Posted by Gizmo6035

Hey Fedex,
any chance of a pic of your mod without having to disassemble anything?
I have the aluminum CCPM upgrade that I am about ready to install so your tips will be put to good use

is that total of pitch and cyclic or pitch only?

Not sure what it is you want a pic of, but that was 14 degrees or more total pitch. You shouldn't have any problems with the upgrade, and should be alot easier just doing the upper half of the frame, I had to take out all of my electronics, for both bottom and upper half frames. With just the upper half you should be able to leave most of the elec alone

Just do one side at a time, should make things real easy. You shouldn't have any problems. On setting up the ccpm I found that all the trex videos here at helifreak really help. If you have any problems don't hesitate to pm me.. I'll try to help. If you have a dremel tool you will need it to grind down the antirotation guide until your servo horn clears, its pretty easy tho, no problems.. The guide could easiely be designed differently to solve this problem, I'm not sure why they didn't.

[Gizmo6035]

The mechanical portion wasn't that bad but getting the radio set up was a real pain
I finaly got the radio set up re-tracked the blades and hovered around the back yard. Even with extremely conservative expo and rates dialed in for the first flight this thing is much more responsive than with the mechanical mixing.