BuschBarber

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Zor - How are things going?

Zor

Past 2:00 AM as I read your last. Will report what Ihave done later today.
I am gong to bed.

Zor

Zor

Hello Rich,

I have been a pretty busy fellow in the last couple of days.

I have solved (I think) my spinner problem on the Skybolt.
Two plastic spiinners have broken on me. They are supposed to be nylon but I do not think so.
Nylon is quite resistant to cracking I thought. They did not crack, The first one simply exploded in three main parts and two of the broken pieces flew more than 20 feet ahead to the grass. My plane was on the picninc table and idling when it occurred.

Last Saturday at the flying field a second spinner threw a chunk of itself when the Saito had a cold and coughed (Hee Hee) "back fired".

I bought an aluminum spinner which I wanted for a long time and the accessory to install it. Las fall (2009) the LHS had no aluminum spinner in stock at all for three blade prop. Back order was 6 weeks and cost $64.00. Lat week I found he had only one three blade spinner and it happened (luck) it was 2 1/2" dia. For $33.00 plus an adaptor for $18.00 and I dug in my pocket. ( Boo Hoo) It was the proper size.

What else did I do ? Oh YA ___I readjusted all the control surfaces aiming at zero trim and zero sub-trim for good balance in cruise flight. It needed a couple of trim clicks on the ailerons and about 12 clicks of up elevator. That is outof 26 click which is the range of the digital trims. On the elevators I ended up with only 3 to 4 thread engagements. I have to open up and go and see what I have available at the servo.

I broke my bank today ___ I bought a sailplane wihelectric motor to climb. We cannot use thermals at our field for the simple reason that there is no thermals there. LOL. It is called "a spectra" a typical 2 meter wingspan, just over 3 pounds weight 10 oz/sq.ft. Claimed to climb to 500 feet in less than one minute.

I queried about a JR R790 receiver to use my XP7202 and that was $99.99. Then I needed 3 servos at $33.00 each. I am now at $200.00 box so I went crazy again and bought a complete kit.
DX7 (HEY I am a big boy now on 2.4 Gig) complete with dual receiver, 4 Ds821 digital servos, Batteries included (Tx and Rx) , charger for both, switch harness, all mounting hadware for servos, the whole "chibang" for $311.00 brand new in JR packaging and purchased from the lHS dealer.

This sailplane uses regular size servos. I checked that on the drawings.

Now you have to tell me that I did the right thing Ha! Ha!

I have changed the settings on the XP7202. See next posting for that.

Incidentally he DX7 manual is a big improvement as I compared some feaures between the two. It is exacly the same features except for the receiver binding (bonding>) and the transmitting RF but the same setting explained in the DX7 manual are much better than in the XP7202 manual.

CUsoon

Zor

BuschBarber

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Glad to see everything is going well for you!!

Zor

Good morning BuschBarber,

NOTE: I often include in my posts things that you obviously know but I am always thinking of the readers that may be new to the hobby and may benefit with some details.

The XP7202 is now set up so that all controls are working fine.
Enough throw and all (except throttle) three respond to dual travel and all three have some exponential of 20%. I like less sensitive controls around the meutral.

Right aileron is on Ail (ch2) and the left aileron is on Flap (ch 6) _ _ (sometime labelled Aux 1).
I switched the left aileron from Aux 2 to flaps (channel 6) to make it more compatible to fellows who have only 6 channels.

So my Aux 2 is now completely (inh) inhibited. Just like it did not exist.

The gear switch works fine even though I do not have a retract gear.

I inhibited Mix 6 and set up the two aileron servos to Mix 5. It works fine. I think I had no need to do that but it was interesting in learning how to play around with the programming ( I hate that word "programming" when in reality I am just setting things up) So . . . channel 2 (Ail) now handles the right wing servo and channel6 (Flaps) handles the left wing servo and that is set up using Mix 5.

The aileron-rudder mix has now been taken off the flap switch and the upper right switch labelled Mix-Rudder Dual Rate is now doing its job as partly labeled "Mix". In position 0 the rudder does not respond to aileron control. In position 1 the rudder does respond (20%) to aileron control.

I think that pretty well cover it as it stands now.

I have spent some time reading stuff in this radio section of this forum and I see quite a few people reporting difficulties (problems) with the DX7. I have the impression however that it is more their misunderstanding than really equipment trouble. I do not blame them for their tough times understanding the manual as they are presented.

I saw your name a few places helping some fellows like you have done for me.
Thanks again, The English in the DX7 manual is an improvement on the XP7202 manual although the setting up is nearly identical.

Wishing you and all a great day,

Zor

BuschBarber

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Thanks!! I retired from Kodak in 2003 and built myself a fast PC. I monitor most of the Radio threads on RCU. I try to help anyone if I feel that I understand what the problem is and I feel that I know the solution. For radios that I do not own, I pull down the manuals and see if I can quickly find the answers.

I spent most of this summer working for the US Census Bureau. I was working 7 days per week and I did not have much time to be Online. Now that I am finished with that job, I have more time to spend on RCU. There are a number of familiar names, I see on many of the threads, providing the same support.

Zor

You and colleagues are doing a great job.
Many, no doubt, arevery grateful.

I am #1 of that group.

Zor

BuschBarber

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Thank you!!

Zor

Hello,

I am not forgetting you.

I am working on building my Spectra sailplane. The fuselage is ready to cover.
The stab and elevator is ready to cut the hinges slots.then cover.

I am thinking of a way of cutting these slots as perfectly as possible by making a small jig.

I have to get some fabric as thin as possible while being strong.
That is to reduce the amoujnt of dope going on. I will have to go browse around the store selling light fabric. Looking for something preferably polyester no more than 0.003" thick.

Let me know if you would like to see a few pictures I am taking as I go along.

I am planning to use the DX7 to fly this sailplane. It is using regular size servos. I have checked that.

So three of the DS821 will go in there.

Midnight here now and am going to bed soon.

Talk to you later.

Zor

BuschBarber

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Thanks!! I would love to see some pictures.

Zor

I will send you some hopefully later today..

Zor

BuschBarber

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Thanks!!

Zor

Hi Rich,

Attached some pictures of my Skybolt at the flying field.

Also some pics of the sailplane I am now building.
It is a Spectra kit from Great Planes designed by the same fellow that designed the Skybolt.

I bought this kit as the only motorized sailplane kit that was available at the only local hobby store.

I wanted to have something a bit more relaxing to fly and get away from the expensive glow fuel.

Zor

BuschBarber

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It looks very nice!! Great job!!

Why do you refer to it as a Sailplane Kit? When I think of a Sailplane, I think of a Glider.

I have two electric powered planes that in the past would have been Glow or Gasoline powered. One is a 84" 29% Aeroworks Katana. It uses 10S 5000mah LiPo's. The other is an 51" Eflite Extra 300 that uses 5S 5000mah LiPo's.

Zor

Hi Rich,

My covering will be "reinforced concrete" ____
Like the heat shrinking plastic (I do not know what plastic that is made of but I do know it tears very easily and the glue is very poor).

My finish is "aceto Butyrate dope" applied over "nitrate dope" and reinforced with 0.005 inch thick polyester threads at 80 threads per inch. The same product as used on full size fabric covered airplanes (ceconite fabric may be known to you).

Its weight is similar to plastic stuff but considerably stronger; does not tear and is intimately penetrated into the frame work compared to surface adhesive of the plastic stuff. It also never wrinkle and keep tight as a drum for over 60 years and more.

Of course the Skybolt is also finished that way and so weremost ofmy models.

I have not played with the DX7 yet but it will control this sailplane.
I agree it is sort of an in between design. An electric powered plane that has good glidng characteristics. Ha! Ha!

Long weekend here "thanksgiving day".

Cheers de Zor

BuschBarber

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There I go again, not reading all the text. I see you had a Spectra glider, as well as the Skybolt.

Zor

Rich,

In post #38 I showed you four pics of some work being done on the new Spectra.
I also included three pics of the Skybolt.

I have other planes in the hangar.
A Piper Super Cruiser 72" wingspan.
A Cessna 195 42" span.
A Cessna 170 36" span.
A Wing Dragon 40" span.
An old Mambo 48"span. It is being converted to full control and possibly becoming a biplane.
A small open cockpit biplane 17" span. ( a cutie )

I sold a few models before leaving Montreal and gave some models away to dear friends of the Montreal Model Bugs group..

Space to carry models was rather limited.

Zor

BuschBarber

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You have a nice fleet.

Zor

Hello BuschBarber,

I have been busy building the Spectra.

I have bought a JRDX7 to operate the Spectra. I got it set up on the table and have been switching it on quite a few times in the last week. It has been working fine until this morning I had a problem.

I turned the transmitter on then the receiver as I have done many times in the last week.
The two LED came on the receivers but no servo motions.

Shut of the receiver switch and then the Xmtr.

Tried again with same results, no servo motion.

Shut off again and restarted a third time. No servo motion.
I shut off the receiver and on the Xmtr I pressed down and select and went to the display of the servo motion.
No motion at all showing on the display.
Turned the Xmtr off.
Waited a ew seconds and turned it on again.

Hey I see the servo display responding to the sticks.
I turned the receiver on and it got the two leds steady (binding good)

The servos are now responding normally.

I am now worried about the reliability of this system.

Iturned all off and back on a couple of times before coming and typing this.
It worked ok.

Ido not know but it would look like if the main On Off switch had two poles, one for the RF and the other pole for the signal generation and the signal had failed to make contact. In other words I had a RF but no modulation.

Any comments ?
Have you heard this case before?

Hoping you read this and thanks for any response.
The story of my life is that I always run into problems no one else ever had.

Zor

Zor

Hi BuschBarber,

I am using your same post to make sure you read this. I hope you do.

I am now wondering about the four DS821 servos.

The transmitter is set at 100% travel in both direction on all 7 channels
The trims on the front of the case are all four at neutral (Centered by the beeping sounds) .
The sub trim are all at zero.

Now how many degrees of servo rotation should I have when I move the transmitter sticks to their full travel ?

I seem to have observed something strange and unexpected but I do not wish to influence your response. I will explain what I observed after I get your reply.

Thanks for your kindness and valuable time.

Zor

BuschBarber

My Feedback: (2)

In all my years in IT, working on hundreds of PC's with the same OS, hardware, and software, there were always occasions where a problem would develop that logically should not have occurred. The same is true with RC equipment.The challenge is to discover what caused the anomaly and how to prevent it from happening again.

It is my understanding that most servos should rotate 60deg on either side of Neutral. Retract servos are an exception. Most servos have Mechanical Stops in the Gear Train, so they cannot rotate past the Mechanical Stop.

Most computer radios allow you to set the End Point Adjustment (EPA) or Travel Volume, from 0% to 120%, 125%, or even 150%. I do not believe that at 100%, you are getting the full 60deg of travel, but I could be wrong. I thought I saw that in a thread somewhere.

I, generally, set my Travel Volume to the max and then adjust my Servo Arm Length and position on the Control Horn, accordingly. Usually, it is suggested that the distance from the Center of the Servo Arm to the point where the Pushrod connects, should be the same as the distance from the Control Surface to the point on the Control Horn where the Pushrod connects. I then use Dual Rates or Expo to keep the aircraft under control.

Zor

BuschBarber,

I am now feeling that I am abusing of your valuable time and all I can say is that I sure appreciate it.
I also have the feeling that we are just about through with this topic and the operation of this system.

I have not had any further "lack of servo response" so I will attribute that to a freak that hopefully will not repeat. If I was the cause, I sure do not know that I did anything wrong since all I did is turn on two switches in their proper sequence. Xmtr on, rcvr on ___rcvr off, Xmtr off.

Will never find the answer to that one.

I had always seen ratings on servos givng the time to rotate 60 deg. I did not test this kind of thing before and thought that the 60 deg would be at 100% settings of the Xmtr travel (EPA). I was wondering on my first test to find 40 deg one way and 38 deg the other way. I have now checked all four servos and they all go 40 deg one way and two go 40 the other way and two 38 the other way. Good enough for my satisfaction. I am forgetting "resolution" for now.
That DX7 does go to 150% on travels and I set it up to 150 on all four servos and made the measurements (accuracy 1 deg.) I got all 4 going to 60 deg one way and the same two as above gong to 60 deg the other way. The two that were going 38 are now going 59 deg the other way. It is easy to interpret less error at 60 than at 38(40) by considering that the pots are not that accurate in linearity of the resistance deposit.

Incidentally for anyone curious, the potentiometers rotated by the sticksare handling a DC voltage, not a pulse or digital.. I had my DC/AC oscilloscope on them and no ac or pulses are detectable as we move the stick around and look at the variable DC voltage as the sticks are moved. The quite obviously control ADC converters later in the cirucitry.
That gives us the same degrees of rotation for the control surfaces as the servo is doing. There is an opportunity here to vary the linkages location on the horns to take advantage of torque and resolution of the servos. For example we might want the elevators to go up 30 degrees while the servo rotate 50 degrees. The elevator reaction is stronger at higher rotation (like the 20 to 30 deg) while the servo is approaching its limit (30 to 50 deg) has the same availale torque but is providing a shorter linear movement of the linkage. (more force).

I think we have the topic beaten to hell by now. LOL

I am at the stage of installing the servos in the Spectra these days.
The drawing is calling for the old style linkages using 1/4 x 1/4 semi hard balsa terminated with piano wire with the wire bent 90 deg into the balsa and the thread wrapping and the glue. Hey we are back in the 1950s and the kit is supplying the material to do this.

Ah!___"The Good Old Times".

I read the nearby long thread discussing Spectrum vs Futaba. I kind of got bored by the end (as of tonight's postings).

Take care and thanks,

Zor