motor and electronics for a track loader

[dsdmax]

Its been a long time since i built R/C cars - those were all kits. Im going to attempt to build a 973 track loader. You guys have set the bar really high - the models i see here are extremely impressive.

Im trying to get my head around the electronics?
- I need two motors - thinking 14.4V dewalt motors - Is there a better alternative?
- speed controller (ESC - do i need one or two? i like the servonaut sound module as well, is that an option based on my motor choice? From what i gather the ESC has to be able to handle the current draw from the motors?
- battery elimination circuit - this will enable me to power the radio receiver with the same battery used for the motors? - can the same battery also power the motor for the hydraulic pump? will i need three ESCs?
- batteries - there seem to be lots of options now. i guess i would like to keep it simple here. something rechargeable. is a run time of 15-20 minutes realistic?
- is there something else i am missing?

I want to get this part worked out first so i can see how much room i will need inside the model. Hopefully i can get some help picking out components and get a bench test up and running. Any help will be appreciated. If there are any books or good sources of detail oriented information that would be appreciated too.

thanks - Fred

[doodlebug]

What scale are you thinking? Take a look at RCP 57 s 955 build,
And take a look at Greg's D-8 build.
Cheers, Neil.

[RCP57]

Here's the link to my build that Neil was talking about...http://rctruckandconstruction.com/sh...ighlight=kitty

The drill motors you are talking about will be great for power but unless they already have, or you make a 90 degree drive for them you may struggle to fit them in. You would most likely need a further reduction on then as well unless you want a really fast trackloader. Sabertooth ESC's are a good choice but there are other choices. I have used Sabertooth 2x12's in all my builds with good success. The nice thing about using that sort of ESC is that they were made for tracked vehicles and setting up your TX is a breeze. You will need another ESC for the pump but everything can run off of the same battery.

Keep us posted!

[doodlebug]

Thanks for the help Reg!
Cheers, Neil.

[dsdmax]

thanks for the updates - i will read through that thread again ... ok so sounds like i will need two ESCs but i can start with one for now and see if i can get the motors turning.

Planning on 1/12 scale so that should give me about 5 inches width in the body. I have mill so will be making the 90 degree turn with bevel gears.

As for the reduction - i really would like to do a planetary gear reduction hub. that said the internal gear will be a problem. I have a rotary table so maybe i could broach one but ... I am also considering a hypocycloid ( more information here - http://www.zincland.com/hypocycloid/ )

not sure i will figure it out but would be cool.

I will get the motors and the ESC and see what i can figure out for the drive train - then model around that.

thanks

[dsdmax]

thanks for the link - your loader is great - love the 4in1 bucket. lots of effort in that alone. wish i knew how to weld. i have a little experience with braising ... going to go that route.

it looks like the 90 degree drive will be a challenge... the miter gears i found have a boar of 3/8 - the motors a 5mm shaft ... finding components is going to be battle...

what motors did you use?

[dsdmax]

great source for gears - http://www.sdp-si.com/Miniature/index.htm

[doodlebug]

I'll send you a link later, on the motors, that me and Greg are using.
Cheers, Neil.

[RCP57]

Originally Posted by dsdmax

thanks for the link - your loader is great - love the 4in1 bucket. lots of effort in that alone. wish i knew how to weld. i have a little experience with braising ... going to go that route.

it looks like the 90 degree drive will be a challenge... the miter gears i found have a boar of 3/8 - the motors a 5mm shaft ... finding components is going to be battle...

what motors did you use?

Thanks very much! I used these motors in the 955 with good success http://www.robotshop.com/ca/en/cytro...gearmotor.html. It is a twenty pound model and they have never stalled on dirt. My Volvo on the other hand, runs these motors and at fifty pounds it is under powered. I would like to try the 955 on 14.4 volts because it is a little slow at 12volts. I think the speed is somewhat realistic though, just not the most exciting piece to run.

[doodlebug]

Originally Posted by doodlebug

I'll send you a link later, on the motors, that me and Greg are using.
Cheers, Neil.

Here's the servocity link, http://www.servocity.com/html/25_rpm...gearmotor.html

Both motors nested together are under 5''

This is the link to Greg's thread, http://rctruckandconstruction.com/sh...ighlight=dozer
His dozer is around 28 lbs.

Cheer's, Neil.

[ihbuilder]

I have 2 18V righthand drive drills in my TD40 . It's scaled at 1:12 . I'm using a dimension engineering 2x25 dual esc

http://www.rctruckandconstruction.co...p?t=761&page=6