TOPIC:

Hi all.

I am in the process of building a Mammoth Dump Truck with my son.
The mechanical side of things is going well.
We have got to the electrics and the Plus 1CH control.
I have replaced the Tamiya MTSC with a ESC and used a splitter cable to provide power to the RX.
My issue is that I can get the rack and pinion lift mechanism to extend by holding the steering one way as expected.
However I cannot get it to retract no matter how much I mess with the tuning pot on the Plus 1CH unit.
I have the original MTSC and have hooked that up just to make sure it's not an issue caused by the ESC, I still get the same behaviour.

I have seen a couple of people on this forum have built mammoth dump trucks. I am hoping someone can give me some ideas on what to try.

It's  Dumbo RC radio gear. I have wondered if it is some incompatibility with the radio gear but as the lift mechanism extends I am not so sure about that.

Thanks for any ideas Dave

Do you have the steering trim on your radio off center?  If so, you may not be sending a 100% steering command in the opposite direction.  If I remember right, I had to crank up my steering travel to 120% to make sure I was sending a big enough command to get the Plus 1CH unit to work in both directions.  Your radio can't adjust end point past 100%, but make sure both directions are at least turned to 100%.  Then try turning the steering trim all the way to the opposite side and see if that works.

The lift system also only works when there is no throttle supplied.  If there is even a tiny throttle command coming from your radio, the lift won't work.  Maybe try unplugging channel 2 from the Plus 1CH module and see if that makes a difference.

Note that the MTSC is actually a pretty good electronic speed controller.  I recommend using it and not replacing it with an external ESC.

Yes I have tried turning the steering trim all the way to the side to see if that made a difference. Had no joy with that though, or with it centered.
Not sure if I can turn up the steering input up on the radio gear I will have a look into that.

The reason I went with the ESC is because I presumed the MTSC wouldn't have low voltage cut off for running LiPo's?

Well after a bit more messing around this morning it would seem the Plus 1CH system isn't compatible with the Dumbo radio gear.
Gave up on the Dumbo and tried a spare radio set out of a HPI and it worked fine.