John Deere 9 Series Tracked Tractor with Planetary Steering

[cooker2003]

Really looking good with some fresh paint.

[egronvold]

Looking good!

[cooker2003]

Next up: disk based on Deere 2660VT design. Close to finalizing, then printing.

[ddmckee54]

How much of the disc will be printed? At first I assumed that all the green would be printed; but then I realized that those were probably just the painted parts on the full-sized disc.

Any possibility of another shot of the disc from a different angle? I'd like to see how your lift linkage works. I've got a Quad-trac that I've been planning on converting to RC and building a 3D printed pan scraper to pull. I'm not above shamelessly copying a good idea when I see one.

Don

[cooker2003]

Basically everything will be printed aside from the disk gangs themselves. The discs are 1.25” fender washers with 3/16” shafting.

Would like more weight to the unit, but the tractor needs to bulk up first.

[cooker2003]

Originally Posted by ddmckee54

How much of the disc will be printed? At first I assumed that all the green would be printed; but then I realized that those were probably just the painted parts on the full-sized disc.

Any possibility of another shot of the disc from a different angle? I'd like to see how your lift linkage works. I've got a Quad-trac that I've been planning on converting to RC and building a 3D printed pan scraper to pull. I'm not above shamelessly copying a good idea when I see one.

Don

Don,

Here is the section showing the lift linkage. I'm using ~1" linear actuators. The linkage should help the implement lift somewhat level.

[ddmckee54]

OK... I'm guessing that there's a shaft that's not shown which connects the lift cylinder to the pivot arms for the wheel assemblies. It looks like you've got hangers that will allow you to extend the shaft out to the wheel assemblies on the wings. Or will the wings just be along for the ride when you lift the center section? If you are lifting with the wing wheels too, how are you going to deal with that shaft when the wings fold? If you've got the centerline of the shaft and the centerline of the hinges lined up correctly, is a u-joint all you need?

As far as bulking up the tractor, if you're just looking for weight I've got a suggestion.... Google "shotgun reloading supplies snake shot for sale". (Or rat shot, same thing.) I used it to add some weight to the tires for my Bruder Manitou 2150 RC conversion, that stuff is great. I had to order a bag of it on-line, I can't remember if it was 20 or 25 pounds, I think it was about $40-$50 - but you get a lot of added weight in a small volume. The snake/rat load shot is a maximum of 1.5mm in diameter and goes down to grain of sand size, so it will fit/fill all the small nooks and crannies.

I 3D printed containers that fit through the wheel opening and also fit around my printed drive wheel/hub. I calculated the volume of the containers at their original size and realized that even using a conservative fill estimate of 50% I woulld be adding over 8 oz. of weight per wheel. I had to reduce the size of the containers, the current size adds about 2.5-3 oz. per wheel. I just used the model rail-roaders' trick of gluing things together with diluted white-glue. I filled the containers with the snake shot, then dribbled on the 50-50 white-glue/water mix until they were completely full, then set things aside for a week to dry. Once dry, everything was bonded together and no amount of banging on the table top would dislodge any of the snake shot.

Just be careful when adding the snake shot, you spill some of it and that crap will go everywhere - DAMHIK.

Don

One more question - in your section view showing the lift linkage the front disc gang supports all appear to be facing the same direction but in the rear gangs they seem to be facing both directions. I assume that's the way they did it on the real thing, any clue as to why?

[frizzen]

I really like the looks of that disk plan.

Great idea using fender washers for the coulters. makes a lot of sence, would simplify making it, and add weight.

I've never tried snake-shot for ballast, i've used mostly #7 or #8 shot.

[cooker2003]

Yes, there is a shaft I didn't model for the lift mechanism. Easy enough to do, just not necessary for all the mates to work properly. Using a universal joint out to the wings, but will have to index them properly so that you can fold the wings without binding (lift will have to be in the up position and you won't be able to let it down without unfolding first). Open to other ideas but this seemed simple. Hydraulics would solve the issue!

The gang supports should all be facing the same way. I did a rebuild in Solidworks and it was fixed - just a quirk with the mirror feature I imagine.

I have some iterating to do on the fold linkage. 1" travel out of the actuator just isn't quite enough. Have a 2" but it's quite a bit bigger. Was trying to avoid using it if possible. Made all the parts like this modular for this exact reason - just some quick linkage parts to reprint, rather than the big frame sections.

[cooker2003]

I found an 8R cab that seems to work a bit better. Had to reprint the cab base to match the new geometry.

[ddmckee54]

Nice excavator, very realistic - looks like a real kid. Bet the controls can get kinda glitchy on it at times - sometimes does what you don't want it to do?

Had a couple of ideas about the fold linkage, rejected both of them because they really wouldn't work. It'll be interesting to see what you come up with.

I've probably already asked, but what layer height do you normally print at?

Don

[skeeter]

I'm LOVING that disk!

[cooker2003]

Reprinted the fuel tanks hollow and filled with #7.5 lead shot. Worked awesome! Maxed out my scale with 500+g added to each tank. Pulls the disk much better now in the dirt. Dry steering without speed is harder on the steering servo for sure.

[redneckfgf]

WOW can you PM me so we can talk about the Stl files you used.
Regards
Frank

[ddmckee54]

Originally Posted by cooker2003

Dry steering without speed is harder on the steering servo for sure.

That's true for any vehicle that can pivot in place. There's just something about being forced to move sideways that treads/wheels don't like. Sometimes friction is our friend and then at other times....

Don

[cooker2003]

9RT got a big upgrade here recently to hydraulics! Now just to finish the disk!

[Lil Giants]

KOOL

What system did you go with?

The couplers look the part at the back.

[cooker2003]

Most of the hydraulic components are from Magom HRC in Spain. It's nice that they provide the CAD models to help with mock-up.

Made some more progress on the disk & getting close to wrapping it up. Functionally, it works really well. I'd like to swap tires with actual rubber ones (versus 3D printed) but haven't pulled the trigger yet.



I've got a couple videos demonstrating the hydraulics - which are quite impressive (strong) for being 10mm diameter. I started to machine my own cylinders on my lathe & quickly realized that is some tedious work. I found the components were available separately from Magom & went that route, which allowed me some more freedom on determining cylinder lengths, etc before brazing them together.

https://photos.app.goo.gl/gVYeEzB3ZYydXE4Z6

https://photos.app.goo.gl/5PG7kBGV1rn3Cmtp9

Going to be switching gears to a planter soon! Got started with a preliminary mock. It will be mainly steel with the row units likely being 3D printed. Planter will be a lot of work, so we'll see how far I get.

[ddmckee54]

Something is not making sense to me on the planter drawings, and that's the length of the triangle braces for the wings. It would seem to me that as the wings fold in, either those braces need to get shorter, or that center support frame needs to get longer, which is it? Or do you have something else to astound us with? (Nice drawings by the way. I've probably asked this before, but what CAD package do you use?)

Don

[cooker2003]

No magic! The forward (insert) part of the hitch telescopes into the rear part of the center frame hitch, just like on the real DB planters.

I use SolidWorks for all my CAD work.