Working Coal Loaders

[mecovey]

I'm building an approximately 1700 square foot transition era HO railroad set in West Virginia (Rowelsburg - M&K Jct area). The B&O is the parent road with my freelanced Pennsylvania Midland running east and west branches from the interchange point at Ashlie Junction.

Coal is the primary commodity and I have 2 on line tipples. One of these is based on the Walthers Mine Tipple and works well. Because it is touching the backdrop, I have run a PVC pipe through the backdrop and coal moves from a large container behind the backdrop to the tipple and is released into the hopper cars. Gravity does a great job and a simple choke cable moves a vane on the end of the PVC tube to control the flow. Trees hide the PVC and the deception is complete.

The other tipple however is based on the Walthers Flood loader and is freestanding. The load track which is some 6 inches below the main is fed by a conveyor that appears out of a nearby hill and must travel about 5 -6 feet crossing over the main before dropping the coal into the loader. I have tried various methods to move the coal including vibration, a conveyor made from a printer ribbon running in PVC channel and an auger made from metal wire sheathing. At least one of these methods should work but I don't seem to be smart enough to figure out how.

The printer ribbon shows the most promise as the ribbon is endless, and using the gearing inside the ribbon cassette I can drive it with a drill. The belt moves along very well however, the "coal" quickly gets under the belt instead of riding on top and soon my PVC channel is filled with coal and the belt is merely running on top of it. The belt isn't massive enough to hold a "V" shape and I have not been successful in running it through a tube rather than a channel either. The coal isn't heavy enough to depress the belt whcih would ensure that the material stays on the belt rather than migrating underneath.

Any help or ides would be greatly appreciated.

Thanks
Mike

[nfmisso]

Hi Mike;

You might want to think about a bucket conveyor, which looks kind of like a chair lift for skiers, except there bucket hanging from it instead of chairs.

Another suggestion is to use a toothed belt, but inside out, so that the coal rides between the teeth. Make a channel guide for it out of acetal (Delrin®) or ptfe (Teflon®), as PVC has more friction.

[mecovey]

Hi Nigel,

Thanks for the reply. I thought about some kind of bucket/chain device kind of like the N&W used at Williamson but given my skills, I have some misgivings about how to make it in a reliable enough fashion to be practical.

The toothed belt is a good idea. Particularly if I could find or make a belt that has "teeth" both crosswise to the axis as well as "sides" between the teeth. It would look almost like a belt of boxes that the coal could ride in. I'm at a loss of what to use for this but I think it may have the most merit.

I wander around Home Depot, Lowes and Menards looking for inspiration but so far I haven't found anything. I suspect when if(?) I find an appropriate material it will be something that was intended for an entirely different purpose.

Your comment about the friction of PVC is right on - Any thought on where I can get Delrin or similar in sizes big enough to make a 6' trough?

Mike

[preceng]

Thanks alot (sarcasm and kiddingly he says). I read your post, now I can't get it out of my head. As an engineer by trade, I spend all day solving my clients problems. Nights I spend solving my railroad's challanges (Soooo relaxing). Now I am obsessed with solving yours. I have some initial thoughts, but need to draw them (occupational hazzard). I can not figure out how to attach a picture file to this reply. If you want to e-mail me ([e-mail]) i can forward a sketch or two. How wide is the ribbon? i assume it is like really thin mylar, or something.

By the way,if anyone knows how to attach a file, I could be more helpful in the future. i have assumed you can not, for security reasons.[8D]

[mecovey]

Hi Alan,

Thanks for the reply-no point in just one of us scratching our heads over this ! The channel is "J" Channel screwed to a piece of plywood. In the channel I threaded a printer ribbon that's about 1/2 inch wide. I thought that by using the printer ribbon, I could use the cassette and associated gears to drive the ribbon and pull the coal. It does work...after a fashion. The ribbon is roughly the same width as the channel and when under load, either the coal spills off the ribbon and gets underneath or the ribbonrotates from horizontal to vertical and spills all the coal. Not exactly a paragon of efficiency. I tried using several small brads across and just above the belt which solved the rotation problem but have not been able to figure out how to keep the stuff on topof the belt rather than migtating under it. I've considered using a wider ribbon to see if it will curve up the sides of the channel and thus hold in the coal but I haven't tried it yet.

Mike

[nfmisso]

Hi Mike;

Look up PLASTICS in your yellow pages, with Menards, Home Depot and Lowes close by, you should be able to find a plastic supply house.

Take a look at:
http://www.pic-design.com/
http://web.mit.edu/rec/www/resources.html
http://www.smallparts.com/
http://www.sdp-si.com/

And especially:
http://www.smallparts.com/products/descriptions/TP62.cfm
http://www.fulong-drivingbelt.com/english/pro_03.htm
http://www.polytechdesign.com/?src=overture

Another idea; a plastic roller chain running in a trough, slightly convex trough to keep the chain against the trough. The coal rides on top, and between the rollers.

Like Allan, I am a design engineer.

Nigel

[nfmisso]

Good morning Mike;

I had another thought last night. A rotating pipe with an auger at the intake end.

The pipe would be mounted at a slight downward angle with a pillow block at both ends. On the intake end there would be an auger bit at the bottom of a hidden hopper. The auger would rotate with the pipe at low rpm. The auger bit could be shrunk (heat pipe up, freeze bit) and/or soldered to the inside of the pipe - use copper pipe it expands faster than steel, and is easier to work with. The rotating pipe will keep the coal moving,

[mecovey]

Good morning,

I hope you and Alan didn't lose too much sleep over this. You suggestion sounds like it might work but I'm having trouble visualizing the pipe/auger/hopper assembly. Could you send me a sketch ? My e-mail address is: [e-mail]. I usually draw in Vizio but have Word as well.

Have a great day
Mike

[nfmisso]

Hi Mike;

I'll e-mail you a .gif file when I get home and scan my pencil sketch.

I had another idea; hollow pin chain with buckets of some sort attached to it.

Or better yet, see figure 2 here: https://sdp-si.com/ss/PDF/79002210.PDF

[preceng]

Mike,

Hope you got my sketch ok. I found that book that shows you how to build an auger type device. Its Realistic Animation, Lighting & Sound. A Kalmbach/Model Railroader Book.

Hope you find some ideas bud

[mecovey]

Allan,
I sure did. Although we.ve been communicating off line, I thought I'd respond here as well so others can follow the thread if they want. I'll check out the book. Thanks
Mike

[Anonymous]

Have you considered using air to blow the coal through a tube? Im a little confused about the geometry of your problem but if your trying to move the coal 5-6 feet this might be the ticket. No moving parts to jam up, just tubing. I wont get into specifics of what Im envisioning but let me know if youre interested and I will be more specific.

Nathan

[vw-bug]

If you are still looking for Derlin and good toother belts. One of the best places for this is
Belts: http://www.smallparts.com/products/descriptions/tb6.cfm
Derlin: http://www.smallparts.com/products/descriptions/sde-sbde.cfm

This should help. My only suggestion is to make sure your covey does run too fast and that it takes small loads . Otherwise I bet you'll run into issues of it getting under the belt

[Anonymous]

How would an auger made out of an old wood working drill bit work. This type of bit has tall flights and a small diameter center. I have several that were for an old hand brace&bit set. The end that chucks is square. Even a regular metal working bit of 1/2" or so should move enough coal for HO scale cars and could be powered by a variable speed drill motor with the bit running through a piece of pipe or tubing. My e-mail address is ~~~~~~~~~~~~~~~~~~~~ if interested.

[mecovey]

Hi Nathan,
I thought about using air but didn't get much further than that. Would the conveyor(delivery pipe) have to be on a downward slope or could it be level ? How would the coal get introduced into the delivery delivery pipe without losing pressure? Sounds intriguing.
Michael

[mecovey]

Tweet469 -

Welcome to the discussion. Alan and others talked about using an auger bit and there was an article in MR sometime back about someone who used an auger bit attached to a wiper moter that was very successful. Moving the product a few inches shouldn't be a problem, it's when you have to move it several feet that the problem of using an auger only a few inches long crops up.

Nigel sent me a drawing of an auger bit solidly attached to a copper pipe held in alignment with pillow blocks that may have promise. Right now I'm leaning toward using a flexible toothed belt (Iwonder if I can get one that's V shaped) or a plastic chain with some sort of bucket arrangement attached to the chain. Appearance isn't all that important since it will be hidden inside a "conveyor housing" it just has to be simple and reliable. I hope that isn't an oxymoron.

Nigle also suggested some web sites for small parts and they look like they might have something appropriate. Rockford is a "factory town" and I plan to check out local sources for the belting and pulleys since I may have to look at several combination of belts and assorted hardware before I buy anything.

I've been really busy with work this past week so I haven't had the time to check anything out except some of the web sites. I really appreciate all the discussion and sharing of ideas on this. Together we ought to be able to figure out something.

Michael

[Anonymous]

Build a working coal tipple
Model Railroader, July 1999 page 84
PVC pipe, an auger bit, and a windshield wiper motor are key ingredients