Introduction and a signal problem

Hello, I’m Brad from Team Hardrada. I’ve been lurking for a short while now and I’ve finally taken the plunge in actually joining! I’m looking forward to getting into this community!

I come with a strange problem. When attending Extreme Robots in Manchester, we discovered a problem with getting our featherweight Harald to react to control inputs. I'll try and be as detailed as possible. When our robot was fully built, with the lid on the distance it would travel before losing signal would be around 20m. When we got to the event, behind the stage it would work almost fine with very occasional cutouts. None that you would notice until you're looking for them. When we got to the featherweight rumble there was no movement to any input on the controller throughout the whole fight. Even in the loading area, there was no movement no matter how close you got to the robot. After the stationary fight we did some more tests. If there was any obstruction between the controller and receiver, the signal would be stopped.

After switching to a very kindly lent controller and receiver, it worked perfectly with plenty of range and no disruptions. Now this naturally seems to me to be a controller/receiver issue however after doing some further tests, the receiver when out of the robot and with no other signals around worked well with no disruptions and plenty of range. When the whole thing was placed back in the robot however, the range decreased significantly.
This has confused us a bit.

If anyone has any ideas of what to try or what the problem may have been at the event I would love to know. Of course, the last thing we want is to go to our next event in June and find the same problem! The controller is an Etronix ET1127 Pulse and we’re using the receiver that came with it. If you need to know anything else, just let me know!

if you get one cheap or easily returnable get a replacement receiver and see if that helps. If not grab be worth grabbing a new kit.

I ran THIS at Manchester and ran fine in every fight even after binky making it do a triple back flip OOTA

I'm not familiar with that particular model of Tx and Rx, but as you say, if a different system worked fine then it certainly points the finger at it. Out of interest, did the robot failsafe ok?

If I remember correctly, was your robot mostly made from HDPE? Was there any chance the Rx in it was touching some metal parts inside that may have been causing issues? Maybe the radio gear is just not transmitting a particularity strong signal and in the noise of the arena and all the other radio equipment is getting drowned out? Maybe there is a problem with your radio gear?

Not much help I'm afraid but if you decide to replace it there are lots of recommendations of proven radio sets on here. From that Mark mentioned above, to the Spektrum, Orange Rx, Flysky to name but a few.

Was the replacement receiver placed in exactly the same place? It is possible that the exact placement of components will make a difference.

I've done some tests and it turns out it was a combination of the inner structure being made of dense aluminium making the perfect signal insulator and placement of the receiver! We've added a tube that raises the aerial out of the inner body and our range has increased to a much better amount. It seems to be working lovely now. Thanks for all of your help!