Building a trainer

[woodhog]

Glad you got her goin For the lights you can use a battle switch or a pico switch i have bought several off ebay and they work perfect ! The radio will have a servo reverse to correct the steering ,also set your end points so the servo is not binding when you are at full lock left and right . You can also set your end point on the throttle so it won't be so fast . What radio did you end up with?

[Espeefan]

TB, congrats on seeing it come to life for the first time!

The steering wheels not being centered properly - that's something you can correct with your radio, or sometimes it can be a mechanical adjustment. Some radios (and I'm not sure what radio you've got) have a programming menu called 'sub-trim'. Sub-trim will adjust the centering position of the servo. In addition to that, you can also adjust the regular trim, without going into a menu. Under, or along side the stick that you are using for steering, there will be a small little slider switch, or momentary push button that will adjust your trim as well. Check your manual for more info on that. Basically both of these features will adjust the servo's centering position, and if your radio does have a sub-trim adjustment, adjust that first. If it doesn't, then use the regular trim adjustment switch or slider, along side the stick. If neither of these give you enough adjustment, then put your trims back to the default 'zero' position on the radio, and you'll have to make a mechanical adjustment to your servo arm, or the linkage going to the steering knuckle. You can remove the servo horn, and turn it one spline to the left, or right, depending what you need. Do this with the servo powered up so the shaft will hold what it thinks is it's centering position. Putting the servo horn back on the shaft, you'll see that you can get it close, but often times not quite perfectly lined up so it is parallel, or perpendicular to your linkage. That's where you'll adjust the sub-trim, or regular trim again. It takes a little playing around, but you'll get there. After doing it one time, it will be really easy the next.

If the servo is turning the opposite way you need it to, then as woodhog said, you'll need to reverse that servo. Your radio will either have some small little switches to do this, or else if it is a computer radio, there will be a menu where you can switch it internally in the programming. You can reverse each channel individually, on your radio, so make sure you do just the one you need. Check the manual. It'll talk about how you can do this!

As for the lights, I'd keep the LEDs. LEDs are more efficient then any grain of wheat bulbs, and as long as you don't push to much voltage through them, they'll outlast everything else on the truck! I wouldn't worry about them being to bright! That's minor. If you want, you can always use a larger value dropping resistor to make them dimmer too. Although if your grain of wheat bulbs are 1.5 volt bulbs, then it really makes it easy to wire them up to a AA battery, if that's what you'd like to do. I would still go with LEDs, but that's just me. LEDs aren't difficult to wire up, once you know what you are doing. Check the tutorial on wiring LEDs, if you haven't already. It's found here - http://www.rctruckandconstruction.co...read.php?t=441

Post some photos of your new ride! Even if it's stock, we'd all like to see it.

[dabears]

Congrats on getting it running!! What radio combo are you using? The centering and reversment is an easy fix one way is to turn the truck on and let the servo center itself, undo the servo horn screw and center your wheels with the horn off the servo and remount it the closest to center as you can get, then screw the horn back down and make final adjustments with the trims. Yes please post pics stock or not we like to see pics!!

[Tinbender]

Got the "battle switch" in the mail today. Hope to get it in tonight.

I think I am going to try to switch servo locations for the throttle and the shifting. Currently the shifting is on the right and the joy stick is spring loaded to center (don't like the idea of the tranny being spring loaded to second gear). The throttle is not spring loaded, so switching them makes sence to me. I can still steer with the left joy stick and this way throttle with the right, it will be spring loaded to "STOP". Makes sence to me, does it to any one else?

I got the steering straightened out, but I had to set up the servo arm 180 degrees out of what the directions said to do. I still have some room over the front axle so it should not present a problem.

I still have lots to learn on these, but I sure am having fun learning. I wish school could have been this much fun.

It was nice to see it run across the floor for the first time. Going to have to play with it a little more! lol.

Working on pics.

[woodhog]

Dont know which radio ya got but if you got a dx8 you can open the radio up and set the gimbal to self center

[Espeefan]

TB, as woodhog suggests, I've also added a factory spring to my stick radio to have a self-centering throttle. It's not to difficult. Internally and mechanically, the left and right sticks are identical, but instead of a spring, they have a simple rachet mechanism so the throttle stick holds it's last position. That's a typical airplane set-up. Get in touch with the manufacturer, ask them what parts you need to make your throttle stick self-centering, and I am sure they can ship you the parts.

This thread might help give you an idea of how easy the conversion is. Some companies prefer you send the radio in, and they will do the work for you, but it's really so simple, you can do it yourself in a few mins.

http://www.rctruckandconstruction.co...entering+stick

[Tinbender]

Woodhog and Espeefan, Thanks for the help on this. Don't know what I am going to do as yet. But in looking at the thread that Espeefan suggested, I now wonder if I can just take the mechinims from the two sticks and just switch them so the throttle would be spring loaded and the tranny shift would not. I bought the Futuba 8j radio, if that helps.

I did switch the servo connects around last night and that does not work so I had to switch them back.

I got the "battle switch" in and hooked up to a LED to verify it was woirking. Once I plugged it into the #5 connection on the reciever, the darned thing lit up. Could not get it to go out no matter which switch on the tranmitter I flipped to any position. Looks like I got me some more reading to do.

I also got two of the tail lights wired up and installed. Was going to install the two head lights ubtil I found out I have lost one of my extra bright LED bulbs I bouth for the headlights and fog lights. Back to Radio Shack to get some more it looks like.

[rsd53]

I'd like to weigh in on this.

Originally Posted by Tinbender

Cammo:
From what I am understanding:
A 23 turn motor will run say 25 miles per hour and have no pulling power
A 55 turn motor will run say 15 miles per hour but have all kinds of pulling power
A 45 turn motor is a fair inbetwwen motor to have a little of each but not a lot of either.

The more turns you have, the larger magnetic field will developed. The other part of the equation comes from the number of poles the motor has. The more poles a motor has, the slower the motor runs. There's a direct relationship between number of poles and torque, for a given field strength.

Let's say a motor is rated at 2000 rpm, has 4 poles and has a torque value of x. If the same motor was wound with 8 poles, it would have a rpm of 1000 and a torque value of 2x. In either case, the same amount of power is consumed.

[1985 kenworth]

Hey congrats on your first build. They are alot of fun, i read you were looking for someone who does decals. There is a guy in london ontario canada that does them. They are water slide decals. I just put clear coat over them so they don't tear once they are on. His website is j-bot.com or. ca... i forgot but go on their and check him out.send him an e-mail if there is something you are interested in.even though it doesn't say 1/14 scale, he should be able to do it.i got my decals for my Blue Mule build in 1/14 scale from him.he is extremely busy so it may take a few days for him to get back to you. He does decals worldwide. Hope that helps you out.The other way to go is if they are generic decals you can take the picture to your local print shop and they can print them on vinyl. for you as long they are not copyright. Although some will print them if for personal use only

[Tinbender]

Well it is built, except for putting on the air horns and the sun-visor. (And the wife still does not know about it, so no one tell her)

I went with a very simple paint job and used a store bought decal and I am calling it "Devil Dog Trucking". I guess the next thing I will have to do is build me some sort of trailer to pull with it.

I did have to rewire the whole thing. I bought the smallest wire that Radio Shack had and it was too big. So I tore apart an Ethernet cable and used the very small wires from it. Works great, reduced the weight, does not look near as bulky.

[Tinbender]

After a great amount of research in this forum and on line, I got the spring loaded 2nd gear problem straightened out. The throttle is now spring loaded to center (or stop position) and the shifting is now free to hold in which ever gear I select. Was scared to death to tackle it, but once I got the radio opened up and saw how all that stuff worked, it was not bad at all to change it around. Now to try it with the truck. Thanks to all for the suggestions, and yes I know I still owe you some pics of it.

[Tinbender]

I have yet another question for the guru's.

I was trying to set the stops on my radio last night and got that accomplished quite well. But when I turned on the truck to make sure of the shifting and steering, I got a buzz sound coming from the motor. I can feel it in the tranny but there is nothing but gears in there so it has to be coming from the motor. The last time I turned it on I did not have this noise but now I do. Any suggestions?

[rsd53]

Originally Posted by Tinbender

I have yet another question for the guru's.

I was trying to set the stops on my radio last night and got that accomplished quite well. But when I turned on the truck to make sure of the shifting and steering, I got a buzz sound coming from the motor. I can feel it in the tranny but there is nothing but gears in there so it has to be coming from the motor. The last time I turned it on I did not have this noise but now I do. Any suggestions?

If you adjusted the stops on the shifting servo, you might be over rotating (binding) the servo in one direction or the other. Does the noise go away, or change, if you change gears without the motor running?

Rob

[Tinbender]

rsd53,

No it does not. I can turn off the radio and leave the truck on and I still get the noise. It does not go away until I either turn off the truck or until I push forward/reverse on the throttle, and then I am not sure the sound of the gears whirling isn't jus drowning out the buzzing sound.

I am at a lose here.

[rsd53]

Originally Posted by Tinbender

rsd53,

No it does not. I can turn off the radio and leave the truck on and I still get the noise. It does not go away until I either turn off the truck or until I push forward/reverse on the throttle, and then I am not sure the sound of the gears whirling isn't jus drowning out the buzzing sound.

I am at a lose here.

Did you make any adjustments to the throttle?

[Tinbender]

rsd53,

No, I left it as it was. I also reset all stops back to factory setting of 100% and I still have the buzz. I bought a sound system and tried to install it and the speaker gave the same buzz so I took it off and now I have this buzz.

Moving the joy stick for the steering and the gear shift has no effect on the buzz. I am thi9nking about removing the drive shaft to see if the gear whine will quite down enough to see if the buzz is still there under throttle.

If this don't get fixed soon, I may not be able to go to the Jackson show.

[rsd53]

Originally Posted by Tinbender

rsd53,

No, I left it as it was. I also reset all stops back to factory setting of 100% and I still have the buzz. I bought a sound system and tried to install it and the speaker gave the same buzz so I took it off and now I have this buzz.

Does it make any difference if you disconnect the motor?

[Tinbender]

Disconnect the motor? Explain, please.

[rsd53]

Originally Posted by Tinbender

Disconnect the motor? Explain, please.

The motor has two wires going to the ESC. There should be plugs on the wires between the motor and ESC. Just unplug one of them, and see if the noise goes away.

[Espeefan]

If you are sure the buzz is coming from the motor, then I can only guess that your neutral throttle position is off a little bit. The speed controller is actually giving the motor some juice at neutral. Not enough to actually make the truck move by itself, but enough to make the motor buzz. This is common noise at the very slow speeds, or when starting a model from a dead stop with a really light throttle application. The moments before the motor begins to spin.

If you are sure you didn't bump the throttle trim one way or the other, you might need to recalibrate your speed controller. In other words, re-teach it neutral, forward, and reverse. Check the manual to see how it's done, if you aren't sure.

Otherwise, it's possible your radio's throttle stick is not centering itself in neutral very well. A weak spring might be keeping it off neutral ever so slightly. The way to check if this is the problem is to turn the radio on, turn the truck on, and then barely move the throttle stick forward, or in reverse. If the motor buzzing stops, and the truck doesn't move, then that is the opposite direction the neutral point on the radio or the speed controller is off. Or you could try adjusting the trim one way or the other, on the throttle channel, until the buzzing stops. I wouldn't use trim adjustments as a permanent fix, but for testing it will let you know what is going on. The correct fix would be to center the trim, then calibrate the speed controller.