Axle suggestions?

[frizzen]

I'm looking for some possible axle suggestions to power an old steel earth moving toy, that i will be able to reconfigure for either Dump or Scrape operation. This is a Power Unit of something 2 axle and articulated. Basically it's an offroad tractor with permanent hitched attachment and no front axle.

The bigger setup 'just as a toy' empty weighs in around 11 lb 6 oz (11.5 Pounds). It's also going to need to be able to drag around a 'pretty good chunk of dirt'. One config has a tapered hopper 6x11.5x5", the other i'm not sure how to actually measure bowl struck or heaped capacity, so let's say 7x6x4" and self loading. Moving some yardage.

I'm thinking it's probably going to need some type of Crawler axle or Gearmotors?

Tires are 4-3/16" tall. 1-1/2" wide
Width between frame rails 2-7/8"
Frame rails 1" tall,
Fenders come out to 5-1/2" wide

I could probably either run each wheel tank-style, or come up with a way to steer off the trailer gooseneck.
If a crawler axle is the best way, a locking-diff would probably help to be able to swing around and still dig in?

[jerry56]

I think the space between your frame rails might dictate what you use...
The heavy duty planetary gear motors are over 100mm long but they have the torque your going to need. The 90 degree worm drive motors might work. Or you might have to machine or somehow build a gear box.
if you have room you could look at 550 80 turn motors and a 3 or 4 to 1 gear reduction feeding a crawler axle but I'm thinking some type of direct drive to the wheels would work out best....
I'm looking at some of the same limitations for my Tournarocker and tournadozer

[frizzen]

Yeah, I'm just hoping there might be a kinda easy solution.



Since you mentioned some of the LeTournau designs, I remembered seeing this Tournarocker build, but that type of gearbox housing machining is probably beyond my skill with the current tooling

https://rctruckandconstruction.com/s...t=Tournarocker

[jerry56]

Yeah I have that one bookmarked to refer back to....but yeah I have noway of building that type of gearbox.
I've thought of using a couple of these to make a pair of gearboxes
https://www.servocity.com/1-50-aluminum-channel/
Those toys are going to take some work they are pretty rough...

[frizzen]

I'll probably need to set up the bruder medical clinic playset to make sure all the action figures have current tetanus shots before we try to drag these out of their grave.

But really they're pressed steel toys, so it just needs a little bit of Sandblaster love and some Paint. I'm not fighting with the 'Serious Collectors' over good toys to 'Ruin'. Most of mine took some vicegrip or hammer & dolly work to put into service. If it doesn't work it's just a test mule, if it does i can do a good one and try some push-pull loading

I'd wondered about those 90 deg. Wormgear boxes, but hadn't messed with any yet to know about durability and driving characteristics. I know worms give great dragbrake, but you've got to be smooth on power, and they tend to wear a little quick

I didn't know if any of the small RockCrawlers could be made strong enough for the forces.
Some 1/10 parts should hold, but it would take some shoehorn work.

I wasn't sure if any of the rc Tanks might have some suitable transmissions.

These real machines were single engine with like 130 hp, top speed of 30 mph. So i'm not wanting to ask for WAY TOO MUCH, but it's still asking for a Lot.

[jerry56]

RC tank setups I think would work but you only have about an inch from the axle to the bottom of the frame...
I have some 90 degree motors coming for another project but I want to see if they will at least fit under the tournadozer...if they do they should fit yours too.
By the way... your Nylint crane with the duals on the rear is one of the earlier ones and kind of rare, most only have a single wheel on each axle

[frizzen]

The Heiliner axle hole is a bit below the frame, and i think it could get away with 'some' additional lift, if axle shifts aft so the fender gap is maintained.

Atleast the Heiliner power unit gives some room under the hood for stashing some components, not sure if the Wooldridge would give more

Yeah, good catch! Both of my Nylint Michigan Cranes are the first version with Dually rear, Knuckle steering, and chrome hole-plugs for headlights. Though i still I have no idea where the boom extension on the 'Truckmaker' one came from.

[ddmckee54]

Frizzen:

If you've got a 3D printer you could probably print that gearbox. Properly designed 3D printed parts will stand up to a LOT of abuse, they just need plenty of wall thickness and plenty of infill. Especially if you've got a nice steel plate that you can bolt them to, like you do. I've printed a lot of the parts for a CNC router that I'm building, and I've got NO concerns about any of them being too flexible.

Don

[jerry56]

Glad to here you say that ddmckee...I've been wondering if I could print something that would stand up to the torque needed to run these.
That would really solve a lot of problems, I've been using 3d printed parts in different places to see how much they would stand.

[frizzen]

That's a really interesting idea ddmckee!
I wouldn't have thought of it since most of the 3D printed stuff i've messed with so far was either done with less stable plastics or at lower % infills.

Bolting a plastic gearbox to the chassis plate with a sandwich-plate doubler below would be a really simple way to keep it stable, and keep the gears sealed up.

Which types of plastics are you having good luck with for the CNC project?

[frizzen]

As of right now i'm thinking i'll be trying some of these asian 12v 90 degree worm gearboxes
https://smile.amazon.com/dp/B08M6731...t_details&th=1

Shaft drive coupler to bolt flange adapter things should let me get wheels mounted.

With the 4" tires these run = 1 foot per revolution, 12v motor at 7.6v, i thought 90 rpm seemed like a good starting point? I may want to drop lower speed once i see how it looks and start load testing

I got one and my BIG concern with Wormgears doesn't look like it'll be an issue. This motor does have a short coast-down to stop before it locks the output, so hopefully i won't be blowing the teeth off the worms. Since it can slow gradually to reduce stress on gears and locks when stopped, I definately do NOT want to use an esc with brake.

My other concern is that this still doesn't look like a lot of motor to drag around a bunch of steel & dirt.

[jerry56]

I know both those toys are HEAVY... especially the scraper and with a full load of dirt?!?!?
Even with two motors I'm not sure they will have the grunt for the scraper.... The belly dump maybe since it just has to haul the weight around not dig in....
I guess the only way to find out is try it...and have a plan "B"
Just seems every build I've read about over the last couple years the builders say these motors don't hold up...IDK why....
I saw a guy do a Tonka scraper last fall but it was on FB so good luck finding it now...
FOUND IT...Finally....I hate looking for stuff on FB....Anyway... here is the scraper Rex Bryson built it.... not sure if he will share any information but...
https://www.facebook.com/photo/?fbid...45960662390545

[frizzen]

Ok, good to know. I hadn't really managed to find any builds using them, so i guess that's why...

After having one of those motors in hand, it had looked like the Heiliner might be able to become a 'tandem engine' scraper (drive to all 4 wheels). But if it's not found to be a durable motor setup, it's probably not going to be worth trying.

I can't open the FB link, so here's a guy driving many different Tonkas
http://www.rccrawler.com/forum/non-c...onversion.html

[jerry56]

I've look at those....he does the Mighty Tonka's I think they are close to 1/10 so he has a pretty wide variety of big motors and axles to chose from

[ddmckee54]

Originally Posted by jerry56

I know both those toys are HEAVY... especially the scraper and with a full load of dirt?!?!?
Even with two motors I'm not sure they will have the grunt for the scraper.... The belly dump maybe since it just has to haul the weight around not dig in....
I guess the only way to find out is try it...and have a plan "B"

I agree with jerry56, even though these toys may be heavy, I don't think they'll have enough traction to be able to dig a load of dirt in the scraper. The belly dump should be doable though.

Don

[ddmckee54]

Frizzen:

I haven't been able to check on this thread for a while, and I didn't see that a couple of months ago you'd asked me a question - until today.

All my printing to this point has been PLA. That includes the cooling fan duct on my D6 printer, and it is only about 10-15mm away from the hot block of the extruder in one spot. I don't leave my parts exposed to a heat source. I did make some motor mounts for the stepper motors on me CNC router. It's still a work in progress so I can't say if they'll hold up or not, but that's what the MPCNC uses so I think it'll be fine?

Don

If I'm concerned about part strength I'll increase the number of perimeter walls and the infill percentage. I usually shoot for about 1-2mm separation between the infill grid-lines if I'm worried about the strength of the part.

[jerry56]

That's when you need a big Cat to push

[frizzen]

i haven't been able to find much info even on the big machines about how much weight and power it takes for blade widths, cutting depth, speeds for various soil conditions. Realistically i'd be happy enough if it plays in crumb rubber or loose dirt. Still be fun even if i have to ''hire'' somebody with a "Big ol' Dozer" to help play for doing more than skim cutting.

So, um, if a guy were thinking about stupid ways some old junk might get a repaint... I know that Kodachrome was available to the public post-WorldWar2, but how are you feeling about Black&White photography?

[jerry56]

What about flat OD green.....then brush away some of the paint to expose the rust.

[jerry56]

I just saw this... just to throw another option at you. Not sure what size this is cause they made a couple different sizes.... but...
https://www.ebay.com/itm/35402324102...kAAOSwSJJiYuQu