1/10 Caterpillar D8T Build (3D Printed)

[Orange RC Works]

Just started on this very challenging build..

[Orange RC Works]

steering and throttle program mix on my Radiolink RC6GS pistol radio...
https://youtu.be/knUPPHZKtQg

[frizzen]

That looks like a really good start!

Which 90 deg. gearmotors are you using for this?
Any idea how much force those tracks can hold before something goes pop?

[Orange RC Works]

Originally Posted by frizzen

That looks like a really good start!

Which 90 deg. gearmotors are you using for this?
Any idea how much force those tracks can hold before something goes pop?

This one, 12v-65rpm, quite big and heavy too. 8mm shafts and 4mm mounting screws...
well, this build will be mostly for show and for the pleasure of seeing it run, so yeah, dont really know whats the max stress the tracks can hold, lets just see how long till the first one explodes...

[frizzen]

Thank you, i thought it looked like that's what you were using. I'd been considering those for a project. Any idea what size motors those use?

Sorry, I wasn't sure if you were planning to try staying plastic track, or prototype a few then send it off later to be printed in metal.

Can't wait to see this one come together

[Orange RC Works]

Originally Posted by frizzen

Thank you, i thought it looked like that's what you were using. I'd been considering those for a project. Any idea what size motors those use?

Sorry, I wasn't sure if you were planning to try staying plastic track, or prototype a few then send it off later to be printed in metal.

Can't wait to see this one come together

Did some research and found out the motors are permanent magnet motors 31ZY, might be 4000 rpm, 3mm motor shafts with screw gear installed, 12v at 65 rpm output on the gearbox shaft ... I used 2s lipo batts at first but the 7.2 volts seem to be underpowered, i changed to 3s and they seem to work well at 11.1 volts since the motors are rated at 12 volts. Im tempted to try a 4s pack but im afraid it might burn the motor out.

[Orange RC Works]

Rolling chassis is ready for a test run...





and the motor test...

https://youtu.be/Cv8Vz40k5Qg

[jerry56]

Wow your really moving along on this one.....looks like the drive train test was a success speed look pretty good....

[Orange RC Works]

Originally Posted by jerry56

Wow your really moving along on this one.....looks like the drive train test was a success speed look pretty good....

At first i thought it was too slow and underpowered with a couple of 2S lipo batts, but when i changed to a 3S set, it changed dramatically.... and i think the speed kind of matches the full scale ones at full throttle... i had it climb a 20 degree incline and it climbed pretty good until the tracks starts sliding on a smooth wood surface lol... i think im ok with the power system and it did not get hot at all (motor & esc)... so i call it a success. thanks

[frizzen]

Yeah good call, 3s makes more sence for the 12v motors.
3.7v, 7.4v, 11.1v

Your prints are looking really nice

[Orange RC Works]

Latest update on this build... im now designing the actuators using a small gearmotor with an M3 lead shaft at 65 rpm, this will be the actuator to tilt the rippers

[Orange RC Works]

Originally Posted by frizzen

Yeah good call, 3s makes more sence for the 12v motors.
3.7v, 7.4v, 11.1v

Your prints are looking really nice

Thanks, I actually do post print processing to smoothen the edges and re drill the holes etc... the bottom of the print usually flare out on my ender 3 so i have to file it off more so when i have to join two parts together, i just hate cleaning up material removed from the prints lol...

[Orange RC Works]

Gearmotor actuators for the rippers is done and installed...



test vidoes...

https://youtu.be/BsQvf6rvS60

https://youtu.be/zY9LS37m5LU

[jerry56]

Are they just N20 motors....

[ddmckee54]

It looks like you are controlling the motors with just a toggle switch. Do you have any end limits on your actuators?

If you have the limits installed, I'd be very interested in seeing how you pulled that off. I've got several projects in the works where end limits on the actuators would be nice to have, but as usual with most RC projects, space is at a premium. Ten pounds in a five pound sack is a good description for a lot of projects.

You said that you are using the M3 version of the gearbox with the threaded rod output as your actuator screw. What are you using for the nut? I know you've got this type of actuator on your powered ramps, but they won't get used as much as the ripper will, or the blade if you use the same type of actuator there. Any concerns about lubrication and/or wear of the screw/nut?

Don

[Orange RC Works]

Originally Posted by ddmckee54

It looks like you are controlling the motors with just a toggle switch. Do you have any end limits on your actuators?

If you have the limits installed, I'd be very interested in seeing how you pulled that off. I've got several projects in the works where end limits on the actuators would be nice to have, but as usual with most RC projects, space is at a premium. Ten pounds in a five pound sack is a good description for a lot of projects.

You said that you are using the M3 version of the gearbox with the threaded rod output as your actuator screw. What are you using for the nut? I know you've got this type of actuator on your powered ramps, but they won't get used as much as the ripper will, or the blade if you use the same type of actuator there. Any concerns about lubrication and/or wear of the screw/nut?

Don

I had to play around with the transmitter to get my settings just the way i wanted it, for the end point (EPA) of both ch 5 & 6, i think its just 20% both ways, and then i had to adjust the subtrim to make the servo horns be inline with the toggle switch... on the other hand, if you are asking about the end point where the motor reaches the longest or the shortest, i just play by feel and sound also, had to wait to hear till the motor starts to slow down and then hit the controls to center the servo, i use the on-off-on toggle switch so it stays when i flick the tx switch.. i was thinking of installing limit switches but with all the wires and switches, i wont look realistic anymore, not worried about cooling or lubrication either coz you only get to use it a few seconds or maybe minutes at a time to adjust the ripper, so it is fully enclosed as you can see...i use a regular m3 nut inserted at the bottom of the actuator rod, but 60rpm at the lead shaft and the M3 threads, it is kinda slow so i ordered the 200rpm ones and see if they will work better. Now, on the blade actuators, i will have to use a faster gearmotor and open the case a bit to have some bit of cooling and some grease on the lead shaft.. also since the 2 actuators will move independently, i may have to use ch 3 & 4 for each

[Orange RC Works]

Originally Posted by jerry56

Are they just N20 motors....

Not really familiar with the motor type...but this is it...they are small..

[jerry56]

Yeah those are n20s.. I have some like that of various rpm's so I can make my own cylinders like you did... been kicking the idea around for a while now just haven't started on them..
Did you print the inside of the cylinder to fit the nut or just press it in.... I have some of the brass press in threads I want to try too....

[Orange RC Works]

Originally Posted by jerry56

Yeah those are n20s.. I have some like that of various rpm's so I can make my own cylinders like you did... been kicking the idea around for a while now just haven't started on them..
Did you print the inside of the cylinder to fit the nut or just press it in.... I have some of the brass press in threads I want to try too....

all parts are printed...and the nut has a slot at one end of the rod where i insert a nut... these are the complete parts of the longer cylinder...

[jerry56]

I see.....
The rod, a cylinder in a cylinder... so you don't see the rotation... That was my thought...
It looks good in 1/10 I'm not sure if I can get everything small enough to look right in 1/16.
I might have to just deal with seeing one cylinder rotating....
But thank you for showing the exploded view it helps a lot...