Programming servos.

[David Jones]

I have the Hitec HFP-25 servo programmer and am trying to program four flap servos on a Ziroli B25. The servos in use are Hitec HS-5665MH digital/programmable servos. I can input information into the servos such as direction of rotation with no problem but, when trying to set end throws, it's as though the information is not stored in the servos memory. I'm pretty sure I'm doing everything as per the instructions, but obviously I'm missing a trick somewhere. Has anybody else had similar problems with this or a similar programmer, or have I got a faulty unit.

I've tried loads of options, resetting the servos back to factory default between each attempt, it's just as though the servos are not holding the data inputted. Any suggestions greatly accepted.

[John Rickett]

Dave,

I've just tried the end point function on a HFP-20 programmer and found that I had to switch off the programmer before unplugging the servo, just unplugging results in the memory not being held.

[David Jones]

Thanks for that John, I think I have been switching the programmer off before disconnecting the servo, but I'm not sure if I did it every time. The programmer is over at Alan's at the moment because it's his model we're trying to sort out, so it will be a few days before I get over there and we have another crack at it. We need to get to grips with it because we want to do the same with the DC3. Another thing that's been mentioned is, should we press "input" after setting each end point. The way the instructions read is to set centre, press M, set each end point, pressing UP/L and DN/R to confirm, set fail safe, then press input. I'm sure it's our lack of computer savvy that's letting us down.

[John Rickett]

Dave, the procedure with the programmer I've got seems to be the same as the one you have. It appears with mine that once the centre and end points have been set and provided I've exited the function by pressing 'input' (which then moves the programme on to the next sequence) or by switching off, the servo successfully remembers the values. I'm afraid I can't offer any more help.

[David Jones]

Thanks for that John. When we get together again, which will probably be weekend, we'll try a few different ideas that we've had, and be a bit more methodical in our approach. I'll keep you posted with our progress. Dave Jones.

[David Jones]

Tried again this weekend and even our electronics / computer wizard Mike Whitehead can't get it to work properly. The general consensus is the unit is faulty so it's being sent back to Al's Hobbies for them to have a look at it. No doubt it will be after Christmas now before I can post any final result.

[Mike altham]

Dave,

Is it still the one you were using on the DC3? If so they dont seem to be the greatest. Best one I have found it the larger older type, not sure of the number. Never had an issue with setting up the 3 servos on the ailerons, elevators and rudder of the big yak.

I could pop over and have a look sometime.

Mike.

[David Jones]

Hi Mike, no, its a new one, the Hitec HFP-25. Mike Whitehead has had another go with it and thinks he's sorted it out. It's something to do with the difference between the ATV on Hitec transmitters and JR / Futaba trannys. We are having a get together at weekend, probably Sunday, to have another go, your presence would be much appreciated if you are free. We'll keep you posted.

[David Jones]

It looks as though we've finaly got to grips with programming these servos. It would appear our mistake was setting up one flap using the ATV on the tx to dial in the end points. Using this flap as a master, we then tried to program the other three to match it. No matter how many attempts we made, we couldn't get all four to work in unison, because we didn't realise the ATV settings in the tx were having an effect on the program in the servos.

It seams the correct way is to have the ATV in the tx at a default setting, in this case 100%. Program one flap to the desired centre point and end throws (up and down) then use that flap as a master through the tx. The remaining servos were then set to match the master, each one plugged into the rx to check the throws, until we had all four working together.

We can now alter the amount of throw on all four flaps as one unit through the tx using sub trim and ATV. I don't know if I've explained it correctly but it does look as though we've solved the problem. So, now that the B25 is sorted, the DC3 should be a doddle. Thanks John for the advice posted on this one.....the learning curve regarding large models continues. Jonesey.