domiflichi

Hello,

I am very new to the rc/hobby world, so have been doing lots of Googling, but still can't figure something out. I recently bought a transmitter:
http://www.ebay.com/itm/322033374196...%3AMEBIDX%3AIT

I received it Monday, but there was 1 'problem' with it: the left control stick does not 'bounce' back to the center (when pushing up or down that is...it does bounce back when going left or right) like the right control stick does.

I've been reading about different 'modes' of a transmitter, like 1 or 2 and so on, but it doesn't seem like the mode of the transmitter has to do with whether that left stick bounces back to center or not.

To keep things simple, let's just say I'm strapping 2 wheelchair motors to a frame that I built, so I want to control those wheelchair motors by using 'tank steering'...so I want that left stick to bounce back to center like the right one does.

I'm not sure how/where to specify / search for when buying a transmitter that behaves this way (both left and right stick bounce back to center when moving them up or down). As a side note, I don't need 6 channels, but I need at least 2 obviously, but would like an extra 1 or 2, so 4-channels would suffice.

flyinwalenda

My Feedback: (5)

You bought a Helicopter Radio. The throttle on that type of radio is set with ho spring return to neutral and typically no ratchet stops.
On most good/well made radios the spring return, ratchet, and stick location can be easily adjusted . On other radios they have to be taken apart to adjust.
On most cheap radios like the one you bought, there are no easy adjustments if there are any at all that can be made. To accomplish what you want you should buy a better made radio that provides easy adjustment of the gimbals (sticks) like a Spektrum.

Steve Percifield

My Feedback: (14)

The left stick does not have a spring on the gimbal because that stick is throttle control on a mode 2 transmitter. If you check your instruction book, it probably tells you how to change the spring from the left stick to the right stick, making it mode 1. Using that info, you can purchase another spring, install it, and accomplish what you want.

domiflichi

Hi,

Thank you both for your replies.

Yeah, I kind of had the feeling that I was buying a cheap one. I didn't think it was going to matter though. I'm going to send it back and look for something else, and guess I'll stay away from the 'helicopter' transmitters. Do I stay away from airplane ones too?

I looked at the manual, and it does mention switching between Mode 1 and 2 briefly, but doesn't talk about at all changing the behavior of the stick. It doesn't mention taking it apart or anything like that either.

Well, thanks again for the replies, I'll keep you guys updated.

rgburrill

Yes iit's cheap but I haven't seen a transmitter yet that doesn't have one stick as a throttle (left or right side) that doesn't have a spring. You will have to make your own. Like said above yu should have instructions (or can easily find them) to convert from mode 2 to mode 1. Just perform half the conversion.

Xpress

For your purposes, you are going to want a transmitter that is setup for robotic style control. Airplane and helicopter style transmitters will always have one of the gimbals that won't spring to center on the vertical axis- this is done on purpose as we use that stick to control motor RPM's and don't need it to spring to center (the difference between 'airplane' and 'helicopter' is that the vertical movement will have a ratchet (for airplane) or no ratchet (for helicopter)).

domiflichi

Wow you guys are awesome, and seem to know your stuff!

@rgburrill - You are correct, one of the sticks (the right side has the spring), but I want both to spring back.

@Xpress - thank you for the tip - I guess I'll be on the lookout for robotic transmitters next...

I'll probably check back in here tomorrow, if I have any updates on my findings...

Steve Percifield

My Feedback: (14)

If you build robots, you can modify the transmitter. Take the back off the transmitter, and look at one of the sticks that has a spring. Notice it's size and how it is attached. The stick without the spring will be identical, except no spring. Buy a spring of the appropriate size, attach it to the springless stick, like the other stick. The sticks are the same in any transmitter, they just don't attach a spring to the stick we use as a throttle.

domiflichi

Hi guys, just wanted to give you an update...

I looked around at Spektrum and Futaba transmitters like you guys recommended, and wow, they are expensive! Seeing this, I decided to see if I could 'modify' the one I have with the necessary parts.

Right off the bat, I found this cool page: http://www.thingiverse.com/thing:927809 but I don't have a 3D printer. This gave me the idea to maybe make my own, so I did - I scanned in the existing control arm from the right-hand control stick, vectorized it, and laser cut it out. Before this, I took specs of the existing spring, and found one with the same specs on McMaster.com so ordered 1 (they come in packs of 12 though). FYI - http://www.mcmaster.com/#catalog/122/1261/=14f8skg (part# 9654K942).

The photo shows the original spring and control arm (spray painted white to scan it in better) on the left, and the new spring and new control arm (laser cut from 1/8" orange acrylic).



When I had the spring and the new control arm, I installed them, and it (mostly) works! My only problem is that the spring is a lot stronger than the 'stock' springs that the transmitter has, so takes a lot of force to move the left control stick up/down.

Thank you everyone for your help...I appreciate it!

crossman

Since you had to buy a package of springs, put one of the new ones on the right stick as well. That way they will have the same tension.
These kind of things are what makes the hobby interesting.

SwampFlier-RCU

You' re on the right track
servocity.com has a lot of stuff for robotics.... but the radios are the same��

SwampFlier-RCU

You' re on the right track
servocity.com has a lot of stuff for robotics.... but the radios are the same😄

domiflichi

Wait, what do you mean the radios are the same?

AndyKunz

Yup. If you're using a Spektrum radio, you can enable the spring centering on both sticks if you like, just using a screwdriver through the back. Take a look at the manual around page 40 or so on changing modes.

Andy