He is at it again! 1:50 Dozer Conversion

[SmallHaul]

Here is a nice small forward & reverse esc:

http://www.ebay.com/itm/ESC-20A-Brus...3255a6&vxp=mtr

[john]

small haul can i ask what you my think is a dumb question, but on the ebay page it says break off? i google searching got alot to read up on tonight haha

[Rvjimd]

Scott,

I think that is what I ordered! Oh, on a side note, do you have a build thread on one of your tonka trucks? I have a semi truck tractor that I want to convert. How did you do the steering and fwd?

John,

The speed controls sometimes have circuit in them that provide a brake function when you let up on the throttle. Something like that is usefull for a race car so when you dive into a corner and let up ub the throttle, it provides a bit of brake effect. This cam be programmable depending on the ESC.

Jim

[SmallHaul]

Originally Posted by john

small haul can i ask what you my think is a dumb question, but on the ebay page it says break off? i google searching got alot to read up on tonight haha

John, i wondered the same thing when i read that and messaged the seller to clarify if it has forward and reverse. He hasn't answered yet though.

Very good question actually.

[SmallHaul]

Originally Posted by Rvjimd

Scott,

I think that is what I ordered! Oh, on a side note, do you have a build thread on one of your tonka trucks? I have a semi truck tractor that I want to convert. How did you do the steering and fwd?

John,

The speed controls sometimes have circuit in them that provide a brake function when you let up on the throttle. Something like that is usefull for a race car so when you dive into a corner and let up ub the throttle, it provides a bit of brake effect. This cam be programmable depending on the ESC.

Jim

Ha! We both posted at the same time. i am curious to hear how it works when you get it.

[john]

I was wondering if that's what it ment thank you both! I ordered one as well. Hoping this was a good idea joining this form hahah I'm getting to many awsome info an ideas!! I found a few decent diecast models on eBay. So with that esc any recomandations for radios or brands? I'm hoping for a 4 channel but is it worth spending more for a 6 channel in case of adding a winch or a scraper in the future?

[Rvjimd]

Here is a short video and pictures of the blade lift on the die cast dozer. Pretty simple setup. Made an aluminum extension for the servo horn. The 2-56 threaded rod is screwed into the blade support frame.

http://youtu.be/cwbXnWAz1Hs

Jim

[john]

very nice!!

[ptebbe]

Amazing project. I don't know how you guys come up with these things
PT

[Rvjimd]

Scott,

Here is a picture of one of the drive cog wheels on the dozer. Did you simply bevel the inside surface, starting at the cup and making it pointed toward the points. Sort of trying to get the cogs to slice or cut the dirt when it comes into the driver? Also, do I want the cup to be more narrow so that there is not so much surface to trap something in the cup between it and the tread?



I had a thought, don't know how well it would work out. What about putting little pieces of low density foam into each square hole of the track chain so debris can not get in?

Jim

[john]

just a thought, wouldnt the foam take alot of power to turn the track? on my 450 case with street pads there are holes on top of where the sprocket tooth would be allowing the tooth to just push the dirt out .. Not sure i you want small holes in your track or if it would even help in that scale. Just throwing an idea out there. i looked at the first tracks pics you posted and it looks like the track frame covers most of the track on ground but i couldnt see if dirt falls from the top of track to the gap from the track frame to the sprocket? my case has a removible rail cleaner, it just a piece of hardened steel that sheers off the bigger pieces. hope you get it going.

[SmallHaul]

Jim, see where the dirt gets compacted between the teeth there, i am calling that a "pocket" and what i do is make that pocket a steep ramp down away from the the side that faces out. So, looking at the drive wheel from the outside you would not see that it has been modified but, if you looked from the backside you would see that the pocket has been sharpen like a serrated knife. Being just soft pot metal though, i would not make the edge too sharp or the drive wheel might wear out very quickly.

Hopefully if you look closely to this photo you can see how i cut a steep ramp into the pocket and just a sharp edge actually touches the drive chain.

[Rvjimd]

Thanks John. I was going to edit the post and ask for other ideas.

I like the thru hole idea, make sense. I'll have to look at them to see.how that might go.

I have some low density foam that I thought would crush real easy as it turns thru the sprockets. I have just enough wear on them now that the tension would not be that much. I think it would be hard to keep it in place..

Jim

[SmallHaul]

i circled the cut/angled pocket.

[Rvjimd]

Cool, that is what I was thinking.

I'm still trying different motor and battery combinations. With the speed controllers I can easily fit two 500 - 3 cell lips under the hood. I hope the ESC's don't smoke

Jim

[john]

small haul thats the drive sprocket? you beveled the teeth on it it looks like? on both sides or just one side of the sprocket? so does that push dirt out or crunch it? good idea

[john]

smokes not good unless it out the pipe eh lol. hey either of you played with smoke generators? think it would be hard to build one from scratch?

[Rvjimd]

Motor question for everybody...

With these mini gear motors I'm using they list the amps @6v stall current. They also list the torque. Is the stall current the current draw when the motor is stalled? Does that have anything to do with the power output or torque?

On the chart below you can see the numbers. I have the following four motors.

LP 250:1 and 298:1
MP 250
HP 250

I like the RPM in the 50-75 range, but I can get some other pinion gears and compensate for that if I need to.

I cut off the column titles. It is stall current, rpm, torque...



Jim

[Rvjimd]

If this project doesn't turn out I keep thinking these track on the undercarriage would make a good looking load on a low boy or deck trailer.




I'm putting the high power motors back on...

Jim

[john]

Isn't more power always better? Lol you can get it together! That's the sweetest cat I've seen hate to see it apart. Did you get your esc working?