Need Radio and Servo Recommendation ASAP

[dogbite]

Hi everyone.  My son is 10 and he's working on a robot project.  We have decided to bite the bullet and buy him a radio and servos so he can start creating his RC robots from "scratch"...  I was looking for a laser 6, but they are discontinued.  What I need is a recommendation for a radio, receiver and 4 servos for a RC bot that is a pooper scooper.  I'd like to have a linear actuator but we will rig something up with a std. servo if it's too tricky.  Anyway, an online source or link would be much appreciated.  I don't mind buying something he will hang onto and use for years to come.  So it's not just this project. He's a robot nut and i want to buy something that is expandable if that's applicable.  Thanks!

[Joker94]

Well if you are looking for a 6 channel(which is probably ideal for RC robotics projects) I would look into the Spektrum Dx6i. the reason being as it is not overly expensive at around $150. the good things about it is that it is a programmable radio so it lets you mix servo movements and mix channels which is really useful.

http://www.robotmarketplace.com/products/0-SPM6600.html

the common standard in the US is Mode 2, throttle on the left, rudder on the left, with aileron and elevator on the right. but in Australia and some european countries use mode 1, throttle and ailerons on the right stick, rudder and elevator on the left stick. but is personal choice.

One of the best features of this type of radio is the recent addition of Orange receivers that are compatible with Spektrum transmitters. and the best thing of all is it is less than 10% of a Spektrum receiver at about $7.50. but keep in mind that the radio comes with a receiver to start with.

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11965

Another option is you are after a cheaper option there is a 2.4Ghz, 6 channel radio that HK sell. it is not as use of friendly and will not be as useful as your son starts working on more advanced platforms.

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=10186

or

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9042

If i was to buy a 1st transmitter i would go for the Dx6i. due to many reasons, its many programmable function, cheap receivers for future projects and it has 10 model memory meaning that you can have 10 different receivers programmed to it which can be very helpful.

Hope this helps

Joker94

[dogbite]

Joker94, that is exactly what I was looking for.  Thank you very much for taking the time to help me and my son.

I am really interested in designing the remote controlled robots, and so is my son.  He doesn't seem to enjoy the automation of the NXT stuff, although he is addicted to legos.  I wanted to get him into the power functions, but they won't be strong enough to do what he needs to for this project.  He's very excited.

Is there a good all around servo you would recommend? The kit on robot marketplace appears to be just the transmitter.  I can buy the receiver for additional. Would you recommend just getting an orange rx?

[Joker94]

I have not had any problems with the Orange receivers. I have 3 and they all work fine. ( it is worth getting a few as then you can be working on multiple projects at the same time and all you have to do is change the model memory on the transmitter). I have them in a couple of robotics projects and a small foam planes with no worries. And the Spektrum receivers can be quite expensive, especially compared to the Orange RX.

As for servos the first servos i got from ebay were Futaba s3003 servo that were fakes and they have been really good, good torque and quite.

I have ordered some servos from Hobby king, the hextronic servos and are expecting them to come shortly(the next week). i am not going to recommend them yet as I have not yet tested them myself but i will let you know how they go, the good thing is they are cheap. they have had plenty of good reviews so i wanted to test them.

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3743

A servo that is used a lot around this forum is the Hitec HS-311. they are known to be good and well suited to robotics. and they are only $8.90. which is a good price for a good servo. you can get a good price from servocity.com

http://www.servocity.com/html/hs-311_standard.html

They are only a few of many servos, but i defiantly like the  HS-311's. do you have a rough idea about how big your robots will be. in terms of weight? this will help people on the forum recommend the best servos.

And  also what country are from, this will also help people recommend the best place to buy stuff for your location as some places can charge lots for shipping if you are not in the US or Canada.

[dogbite]

If i had to guess right now the weight of our robot, it would be 5 -10 lbs?  does that sound right?  Maybe closer to 5. 

Also, I am in the US, northeast.

TOday we picked up theDX6i and rx.  we grabbed ONE servo, because hobby shop had pretty much nothing.  It's a 322HD.  However, I didn't get a battery. I assumed it would have come with the Tx and Rx.

Oh well.  I'll look around tomorrow.  What kind of servo/motors should we use for the WHEELS?

[Joker94]

TOday we picked up theDX6i and rx.  we grabbed ONE servo, because hobby shop had pretty much nothing.  It's a 322HD.  However, I didn't get a battery. I assumed it would have come with the Tx and Rx.

cool, i really like the Dx6i and it is great for robotics.

Well you can modify servos for continuous rotation to use them as wheels. The thing with this is when you plug a modified servo into the receiver and turn it on it will turn fast and not really react to stick control. what you have to do is go into the menu options and put the sub-trim of the channel you are using to maximum/minimum( what ever way slows down the servo) when you have done this it will still turn slowly, from here you should be able to use the trim tabs on the sides to stop the wheel completely.

you can also use the features of your radio to mix the control onto one stick making control easier. although it will take up more channels. I am currently working on a way of plugging the servos into a micro controller and from there send a signal from receiver to condense the controls down to 2 channels and 1 stick. when this is done i will post how to do it.

I will upload a video to youtube showing how to setup servos and an RC transmitter if that will help?

If you want to go for a motor there are motor controllers called Sabre tooth motor controllers from a company called dimension engineering. you can get a version specifically designed to connect to an RC receiver. then you just have to find some appropriate motors and hook it all up. this will be a way of simplifying the set up but it is more expensive than going for a servo.

if you go for a servo you have to either chose a servo with high enough torque or keep your robots under that torque for them to handle the weight. and I have always found to allow room to add a lot more weight as things generally come up heavier than what i expect them to be.

A for the weight, if they are going to be smaller robots I would expect them to be around the 5 pound mark. but compile a list of all the things you can think of that you are going to incorporate onto the robot so you have a rough idea.

[Joker94]

Well got my servos in the mail yesterday and i have to say  i am very impressed with the HX5010

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=3743

and the HXT900

http://hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=662

i haven't put them through a lot of testing but i have hooked them up to the orangeRX and done some movement tests and a load test. what impressed me the most is that the HX5010 moved on almost all of the trim movements. which for a cheaper servo is very good.

overall on both of the servos the movement was smooth and very quite. a very good cheaper servo. i plan to use them both in my next robot, will post my thoughts when i write up about my robot.