Non-GS plastics question

[Joe Nardy]

First, let me explain what I'm trying to do. My Toro snowblower has what I think is a design flaw. The blower has rubber paddles that scoop the snow and eject it out through the chute. Also, tilting the blower forward causes the paddles to contact the pavement more, pulling the blower forward. This all works very well, for the most part. The problem is that as the paddles wear and/or if the blower is aggressively tilted to dig down in packed snow the side plates contact the pavement and wear through the thin sheet metal lip on the bottom edge. This isn't a big deal initially as the metal side plate slides reasonably well on the pavement. But when the side plates start to wear through the blower drags horribly on the pavement. The side plates cost about $60 for the pair and will eventually do the same thing. I decided to try to fabricate something to help the problem. Below is what I came up with today:



I cut a thick nylon specialty washer roughly in half then drilled and bolted it to the side plate at the contact point. This works very well. The blower can be aggressively tilted forward and will smoothly glide forward. However, it looks like the nylon will wear pretty quickly so I'm looking for a more durable plastic to use for this purpose.

I'm also considering making something like the pic below from a similar material to protect more of the side plate edges:



Does anyone have any suggestions regarding a durable, reasonably priced plastic that I could use for this project? A source to buy the material from would be greatly appreciated as well.

Thanks,
Joe

[Nessism]

I'd use 1/4" steel or aluminum. Plastic will wear too fast.

BTW, I had a similar snow blower when I lived in Ohio and I loved that thing.

[jonmasaya]

I'd so go with some sort of Delrin plastic.

http://en.wikipedia.org/wiki/Polyoxymethylene_plastic

It's super low friction and pretty robust. I've used it before for machine joints, there's no need to lubricate. I'd imagine it would slide across the pavement nicely.

You can order blocks online, or what I used to do... pick up a plastic cutting board at a drug store. The translucent white ones are usually the same material.

[Joe Nardy]

I'd use 1/4" steel or aluminum. Plastic will wear too fast.

BTW, I had a similar snow blower when I lived in Ohio and I loved that thing.

Ed,

I know steel or aluminum will wear longer but I really like how smoothly the blower glides with the plastic. The plastic washers were $1.80 apiece and I can fabricate and install them in a few minutes. I found some info on Ultra High Molecular Weight (UHMW) Polyethylene which is 'a very tough material, with the highest impact strength of any thermoplastic presently made.[citation needed] It is highly resistant to corrosive chemicals, with exception of oxidizing acids. It has extremely low moisture absorption, has a very low coefficient of friction, is self-lubricating, and is highly resistant to abrasion (15 times more resistant to abrasion than carbon steel). Its coefficient of friction is significantly lower than that of nylon and acetal, and is comparable to that of Teflon, but UHMWPE has better abrasion resistance than Teflon. It is odorless, tasteless, and nontoxic.'

I can get 3/4" x 4" sheets for $4.99 a foot here.

I might give this a try. I'm still open for any suggestions and sources.

Yes, the Toro two-stroke snowblowers are outstanding......unless your stepson runs non-premix fuel in them. Mine now has a new short block.

Thanks,
Joe

[bonanzadave]

I can get you some Cell Cast Acrylic (1/2" thick) that I make airplane windows from. Its actually kinda brittle and may crack in your application. I may also have various ABS or Poly carb scraps laying around. You can experiment with whatever. What the H its free !! Send me your address and a rough blank size.

[Joe Nardy]

I'd so go with some sort of Delrin plastic.

http://en.wikipedia.org/wiki/Polyoxymethylene_plastic

It's super low friction and pretty robust. I've used it before for machine joints, there's no need to lubricate. I'd imagine it would slide across the pavement nicely.

You can order blocks online, or what I used to do... pick up a plastic cutting board at a drug store. The translucent white ones are usually the same material.

I looked at Delrin because I know it is used for frame sliders but it is pretty expensive. The cutting board idea is GREAT! That's why I ask here.

Thanks,
Joe

[jonmasaya]

I looked at Delrin because I know it is used for frame sliders but it is pretty expensive. The cutting board idea is GREAT! That's why I ask here.

Thanks,
Joe

I guess I should clarify, the cutting boards aren't Delrin, they're High Density Polyethelyne, but will probably be good enough for what you need. Also cheaper to replace when they eventually wear down.

[Steve]

To help minimize the wear rate, make your contact patch as long as possible.
That small washer gave you a good start, but if you can make those blocks 4" or longer, they will wear much longer.

.

[bwringer]

You can get UHMW and many other plastics besides from McMaster-Carr.

http://www.mcmaster.com

You could try the cutting board plastic first, though. I believe it melts at a lower temp than nylon or UHMW, so it would take a lot longer to cut out a large shape without melting.

I just paid $6 at WallyWorld for a cutting board to make a big spring preload spacer for my V-Strom's shock. The plastic kept melting on my hole saws, but other than that it was pretty easy.

I believe we have the same snow blower, but for some odd reason nothing has worn out yet...

[Joe Nardy]

I guess I should clarify, the cutting boards aren't Delrin, they're High Density Polyethelyne, but will probably be good enough for what you need. Also cheaper to replace when they eventually wear down.

So, the cutting boards are like the UHMW polyethylene I mentioned above? If so, that would be perfect.

To help minimize the wear rate, make your contact patch as long as possible.
That small washer gave you a good start, but if you can make those blocks 4" or longer, they will wear much longer.

Yes, that was my original intent. I made the patterns before going to the hardware store to search for materials. They did not have any thick steel, aluminum, or plastic so I looked for alternatives. (I didn't think of the cutting board idea). The nylon washer was a very cheap way to see if my idea would work. So, the plan is to both find more abrasion resistant plastic and increase contact area by using longer and wider blocks.

You can get UHMW and many other plastics besides from McMaster-Carr.

http://www.mcmaster.com

You could try the cutting board plastic first, though. I believe it melts at a lower temp than nylon or UHMW, so it would take a lot longer to cut out a large shape without melting.

I just paid $6 at WallyWorld for a cutting board to make a big spring preload spacer for my V-Strom's shock. The plastic kept melting on my hole saws, but other than that it was pretty easy.

I believe we have the same snow blower, but for some odd reason nothing has worn out yet...

Yep, cutting board will be my first attempt.

I believe my snowblower wears out parts quickly due to the nature of the concrete on both my driveway and sidewalks. The tiny traction grooves run perpendicular to snowblower direction and are very abrasive. I have a lot of driveway area and around 300 feet of sidewalk so it all adds up to quick wear.

Thanks,
Joe

[bwringer]

I believe my snowblower wears out parts quickly due to the nature of the concrete on both my driveway and sidewalks. The tiny traction grooves run perpendicular to snowblower direction and are very abrasive. I have a lot of driveway area and around 300 feet of sidewalk so it all adds up to quick wear.

Thanks,
Joe

No, I believe your snowblower wears out parts quickly because you live in the frickin' arctic tundra.

Every winter, I wonder why the hell anyone ever settled north of the Mason-Dixon line...

[twr1776]

Joe, is yours the paddle or reel type? Mine is the reel type and they have a plastic scraper by the inlet on the pavement side that is replaceable and it keeps the steel parts slightly off the ground. Tim

Part # 17

http://www.partstree.com/parts/?lc=snapper&mn=3201S+20%22+3+HP+Single+Stage+Snow+Thrower+Series+1&dn=7769

[scrapper]

I don't know what it is made from but if you check woodworking supplies they make some stuff that is real slick it is for attaching to the rip fences on table saws and anything else you need to make slick.It helps slide the wood through the machine. The stuff is made thin for rip fences but I believe it comes thicker. I am not sure but I would think rockler would sell it. It is self lubricating, not sure how? I got mine at thewoodworking show in Indy and it was cheap, cost more for thicker pieces. Hope it points you in the right direction.

[Joe Nardy]

Thanks to everyone for their suggestions. I picked up a cutting board at Wal-Mart and made my 'bumpers'. They seem to work very well although I've only used the blower twice. It will see more action soon as we're getting hit with a lot of snow today. The bumpers make the blower glide much better and seem to be wearing well so far. Below are pics of the final result:







Thanks again for all the suggestions,
Joe

[Larry D]

Looks nice, Joe.

When you get done with your driveway, would you come down to Indy and get mine ???

Stupid snow..........