1:14 RC Tracked Conveyor

[Blender]

A couple years ago a local guy built a really nice trommel. Only issue is the feed is too tall for most machines to load on flat ground. This device will solve that. Will pull double duty as being able to deposit shredded rubber into 5 gallon buckets to clean up at the end of events. Ideally a machine that can be setup in the morning and let run unattended all day.

Based on Terex, but will be between sizes with functional differences to work in small scale. Not a true replica.




Drive belt has been the key part. Bruder's is really nice with cups for steep angles, but too small. Spliced rubber sheet looks great and is super thin, but is never true (when i build it). Megadyne T150 is perfect, but they never pointed me to a distributor in the US. Tried several custom belts from Misumi until i found the right one. Lots of width options, thin and has a woven texture for some grip. Only bummer is it's green. Built a simple fixture to test belts. Rollers are 0.75" 19mm dia aluminum on 8mm shafts. Aquarium gravel transports best at less than 20 degree incline. Granulated rubber appears to tolerate up to 27.5 deg without tumbling. Good news for a short conveyor that still has enough vertical reach. This is much steeper than the real machines




Some details

• Tracks and drive is from Double E Volvo 160 excavator. Temped to use the gearbox too
• Hydraulic cylinders from Magom
• Valves are Lesu 4 spool i have on hand.
• Pump: Scaleart tiny pump ordered to try out. Otherwise i'll get another Leimbach since they are a sure thing.
• Hydraulic functions are: conveyor height, conveyor fold, rear feet and hopper discharge sluice gate.
• DC gearmotors for feeder and conveyor
• runs on 3S 5000 mah lipo to be common to my trucks. External strobe light will act as low voltage warning since transmitter won't always be connected to receive telemetry data
• low hopper <7 in from ground to be fed with modest sized wheel loaders (MCL8), but wide enough for a full bucket from something larger (wedico Cat 966G) or excavator of any size
• Construction will be almost entirely stainless steel sheet. Trying to minimize machined parts for simplicity
• When folded must fit into my existing case geometry.
  

Already confirmed i can alter the failsafe setting of the receiver inside to hold speed of both conveyors if/when radio signal is lost. External power switch will keep things mostly safe.



Still a ton to do before i can start on the physical build. Focus will be on the hopper/feeder to verify is works.

[Zabco]

Oh this will be cool. I love this type of equipment. There is a company only a few miles from where I live that makes all sorts of crushing, screening and conveyor systems. They are called Screen Machine Industries and I always like driving by their facility because they always have some neat looking equipment sitting in their yard. Their web site is screenmachine.com if you want to see what they make.

Could you glue thin strips of rubber to the belt to assist with moving the material up the conveyor?

[Blender]

Screen machine has some cool stuff. Mobile Crusher is too ambition for me, but I'd love one. Same with the mobile shredder. Too cool.

Glueing on some ribs or scoops is exactly plan B. Hope I don't need it, but I'll do what it takes. Rubber strips of all thicknesses are readily available on McMaster-Carr.

[ddmckee54]

I used to work in a food processing plant, and I've seen a lot of conveyor belts in various widths, from 50+ inches down to a couple of inches. Buying the stock for the belts ain't cheap.

Have you thought about making your own custom belts? Used treadmill belts belts can be had for a few bucks, they are usually only a couple mm thick, and they are the right color. They can be split to the desired width, and then scarf joined to length. Winky's Workshop had an excellent video on how to make a custom flat belt using heat cured glue. A 90 degree scarf joint is the easiest to make, but will be a little noisier when the joint hits a pulley/roller. An angled scarf joint will be quieter as it runs over the rollers.

Don't forget to crown the pulleys/rollers, it makes tracking the belt much easier - crowning the pulley will make the belt want to self-center. A few turns of tape in the middle of the pulley/roller should be enough, just be sure to wrap the tape in the proper direction. A small slice of heat shrink tubing might also work. A softer material with a lot of grip on the drive pulley/roller helps avoid belt slippage, and be sure to make the idler pulley/roller adjustable for belt tracking. Also, you want to pile your product up in the middle of the belt when you load it onto the belt, keep it away from the edges. The product will spread out as it travels, every time it gets jiggled around a little it'll spread out.

If you do add ribs to the belt, I'd keep them as narrow as possible, and as far apart as possible. The ribs are going to make the belt stiffer and harder to drive around the pulleys/rollers. Make your drive and driven pulleys as large as possible, idler rollers can be small, but the end pulleys/rollers need to be big.

Don

[Blender]

Great info Don.

I did experiment with building my own belt. I was never happy with it. I'm sure it's partially skill based. Also looked at gravity molding my own, but the required mold size is just too big to be practical. Instead I'm using these:

https://us.misumi-ec.com

1mm thick, width in 5mm increment and custom length in 10mm steps. Only cost $10 each for 50mm x700mm

Tracking was exactly my concern the fixture above was assembled with great care to try and get everything as square and true as possible. Just to see how much adjustment I really need. Tracked OK, but not perfect. Crowned rollers might be exactly what I need. Should be able to modify what I have to see how it acts.

[ddmckee54]

That's really not a bad price, when I was looking for U.S. suppliers the 50mm stuff was about $5/foot. You only need a couple of degrees of crown on the rollers. If you've got solid rollers, just turn a shallow taper on each end and leave a small flat section in the middle. It seems counter-intuitive, but the belt will track to the high side - that's how the crown works.

If you don't like the green color of the belt, vinyl upholstery dyes are available at a lot of auto parts locations. I've seen prices from $11, to over $30 per spray bomb. 40 some years ago I changed the headliner color on my '57 Ranch Wagon using that, worked like a charm and only took 2 cans.