Having a bad day with my USA1 and Mod Clod

[richytanimal]

Grrrrrrr[!]

Thought I'd reinstate the 4 wheel steering on my USA1 today, managed that, then thought I'd put my twin motor esc in to replace the knackered old msc. Did that, now when I go forward and turn (either direction) the servo straightens up!!! When I let the power off it turn's again!! Tried another reciever and that improved it but now the esc is cutting out!! Put it back on the shelf in disgust and took my "reliable" mod clod out for a spin. It's running 4 channel radio gear and twin hitec 645's, now that's playing up!! If I pull back and right on the right stick, the servo's go mad and the esc cuts out! All the left stick functions are fine. I only have to have one servo plugged into either of the right stick channels and it drives the others crazy!!

That's gone back on the shelf for a bit now, I'm off to have a beer!![xx(]

[raemin]

Have you tried to cut the esc red wire and install a separate battery pack? These hitec hi-orque servo really drag the esc power supply, above all if your receiver is "bec".

[richytanimal]

Already running with a seperate battery pack, also tried different batteries to power the reciever, tried one of my reciever nicad packs, tried 4 2000mah batteries, that improved it slightly but didn't cure it.[]

Think my reciever is on it's way out[]

It has to be Monday today!!

[raemin]

Is the receiver a "bec" type, if so you would have to wire directly the servo +/- to the battery +/- -

[richytanimal]

It's not a bec type, gonna try and borrow another 4 channel reciever tommorrow and see if that makes a difference.[xx(]

[raemin]

And don't forget to cut the esc red wire, otherwise, the esc will "drain" the current out of the receiver. I already had such problem with a tekin ESC and an hitec 625: when using a big (9t motor) the current drop was so high that the receiver would go mad, I installed a separate batt pack to no avail until I cut the ESC red wire.

In order to reduce receiver batt size, what i also do, is to cut the both the esc and servo red wires and hook them together. The receiver is fed with a separated 4.8v 150mah battery. Hence the ESC feeds the servo directly and the receiver has its own separate power supply. Two separate power supply is the best way to avoid interferences.

[richytanimal]

I might try linking the esc to the servo direct!

Thanks.

[DJTheo]

Wouldn't it be better to put a stong pack (NiMH AA) to feed the servo directly and let the esc handle only the receiver?

Cheers

[raemin]

quote:Originally posted by DJTheo

let the esc handle only the receiver?

Cheers

---

id="quote">id="quote">

Actually not, because in case of current drop, the esc will not be able to feed the receiver. It's better to have low current on the servo (=sloggish servo) rather than low current on the receiver (=eratic behaviour).

[richytanimal]

Hi everyone, thanks for the tips and hints, put seperate power to servo's, reciever etc, still got probs but only with the channels from the right hand stick! I can put both servo's in the left stick outputs with no probs, but as soon as I put anything in either of the others and pull the right stick down and right, it interferes with all the channels again!

If i servo reverse either of the right hand channels (on the transmitter)the problem gets reversed ie pushing up and right or left interferes with all the other channels. Think it must be the reciever, will test it with another reciever (as soon as I can get hold of one)

Anyone got a working 4 channel 40mhz FM reciever going cheap?[?]

Rich

[DJTheo]

quote:

Actually not, because in case of current drop, the esc will not be able to feed the receiver. It's better to have low current on the servo (=sloggish servo) rather than low current on the receiver (=eratic behaviour).

---

id="quote">id="quote">

Interesting, all the ESC I know never had problems providing the few mA current for the Rx, usually the high servo current was causing problems. Since I am using a high power servo on a work project on a self designed board I found out that the erratic behavior isn't so much caused by low current (Rx anyway needs only tiny current) but on interference from servo (Back EMF and sparking), since I soldered a capacitor in parallel like on our car motors the problems disappeared.

Cheers