Unit Cable Hoe

[tracksntreadslou]

Mike I think you sumed it up pretty good ...It also gives us a good excuse to play with our old toys and not look too foolish lol

[SmallHaul]

Thank You very much Mike.

Thanks Lou.

I really enjoy converting them and never get tired of running them.

[modelman]

SmallHaul-I will enjoy watching this build! These old machines are my main interest. Do you have any worries over the hi amp draw you will be putting on the servos for track drives? I didn't think servos would handle much continous load.

[SmallHaul]

Originally Posted by modelman

SmallHaul-I will enjoy watching this build! These old machines are my main interest. Do you have any worries over the hi amp draw you will be putting on the servos for track drives? I didn't think servos would handle much continous load.

Well, here is what I am thinking... The crowd drum on my doepke dragline has enough power to fairly easily pull the entire crane up hill on (free wheeling on its wheels) and that is one 200oz inch servo. So, I figure if I have one 200oz inch servo on each track that should be more than enough power to propel the entire crane up a steep hill. Worst case scenario is the 200oz inch servos are not strong enough and then I'll just have to swap them for Hitec 7955tg servos (well over 300oz inches of torque @ 6volts) that cost $100 a piece. I have one of these servos in my Mack dump truck running the dump mechanism and the servo has so much power that even if you overload the bed with dirt the servo doesn't even sound like it is working hard to lift & dump it.

[Dreamweaver]

Originally Posted by SmallHaul

Well, here is what I am thinking... The crowd drum on my doepke dragline has enough power to fairly easily pull the entire crane up hill on (free wheeling on its wheels) and that is one 200oz inch servo. So, I figure if I have one 200oz inch servo on each track that should be more than enough power to propel the entire crane up a steep hill. Worst case scenario is the 200oz inch servos are not strong enough and then I'll just have to swap them for Hitec 7955tg servos (well over 300oz inches of torque @ 6volts) that cost $100 a piece. I have one of these servos in my Mack dump truck running the dump mechanism and the servo has so much power that even if you overload the bed with dirt the servo doesn't even sound like it is working hard to lift & dump it.

WOW... Scott speaks Greek Or at least that's what I am hearing.

[SmallHaul]

Originally Posted by Dreamweaver

WOW... Scott speaks Greek Or at least that's what I am hearing.

HA! Here is how much power one 200 oz inch servo has.

http://www.youtube.com/watch?v=RDJwvo3claI

[9W Monighan]

That looks powerful enough Scott. You ought to put a ammeter in line to see how much current draw you have.

[SmallHaul]

Originally Posted by modelman

Do you have any worries over the hi amp draw you will be putting on the servos for track drives? I didn't think servos would handle much continous load.

Oops..sorry Modelman. the whole time I am thinking power not continuous load.

Thanks for the heads up Steve.

I'll check the current and post it up. But, I really don't think it will be enough to overheat the servo.

[9W Monighan]

It's not like you'll be traveling any great distance. So the duty cycle would be down. Do a test on a junk one and try to kill it.

[SmallHaul]

Originally Posted by 9W Monighan

It's not like you'll be traveling any great distance. So the duty cycle would be down. Do a test on a junk one and try to kill it.

The servos I ordered for the drive are only $11.70 free shipping.
So, if they fail no biggie... They have all metal gears and over 200 oz of torque. From what I read the MG996R's hold up very well to abuse.

http://www.hobbypartz.com/servo-mg996r.html

[Stuff]

11.70 each for 200oz servos!! **** man!!


also that video was awesome!!

[SmallHaul]

Originally Posted by Stuff

11.70 each for 200oz servos!! **** man!!


also that video was awesome!!

Thanks Dean.

Also, every gear in that servo is metal and it is a digital servo as well. I will disassemble one when I get them and see how well they are made.

[doodlebug]

Dragline Wheelie

[Stuff]

this is what im getting http://www.servodatabase.com/servo/springrc/sm-s4315r




Torque:
4.8V: 201.4 oz-in (14.50 kg-cm)
6.0V: 213.9 oz-in (15.40 kg-cm)

and are factory 360 robotic servos with J-channel connector. gotta watch some are a square 4 pin connector that i haven't seen before.

[SmallHaul]

The bucket is made. It is not perfect but, it is the first time I ever brazed aluminum. I used the aluminum weld sticks from harbor freight. I sure learned a lot using it and will be able to do a much neater job the next time I use it. The ears at the back of the bucket will have holes drilled in them for mounting the rear pivot arm. I am surprised how heavy it is now that it is all welded together. I'll probably eventually make a another one out of thinner aluminum and make it neater.

[Stuff]

that turned out pretty good!

[Stuff]

wow that does sound tricky! what did you use for the heat? propane torch or go to oxy/acc torch?

[RCTech9]

Bucket looks good.

[SmallHaul]

Originally Posted by Stuff

wow that does sound tricky! what did you use for the heat? propane torch or go to oxy/acc torch?

A little map gas bottle with a hose & torch head.

Originally Posted by RCTech9

Bucket looks good.

Thanks.

I used some scrap aluminum that I had laying around to jury rig a stick & boom to figure out the best length and pivot locations. Next I need to add the pulley at the top of the stick and the pulley down by the bucket because pulley the cable 1/1 is a little too fast and having twice the power will be nice. I have the servo rate turned down so that it doesn't move too fast setup directly... I'll probably use these dimensions on the final boom. It digs ok with this sloppy setup so, with teeth on the bucket and a bigger mouth opening (the stick is in the way on the jury rigged setup) it should dig very well.

http://www.youtube.com/watch?v=JXdtQ9FA-Xs

[Stuff]

it looked to be doing okay as it was in the video lol. This is gonna be a heck of a project of yours!

the boom line, is it just one piece from the lower boom to the servo then back to the top of the boom?