# HDPE scraper bar



## dbert (Aug 25, 2013)

This project currently has about 3 minutes invested. A few quick passes on a table saw. I'm trying to decide if it will work. The cutting board was a donor (free). I wouldn't have picked this color. It's perfect for experimenting. I'd really like to put the HDPE scraper bar right on the cement for a clean pass. It's cut long (wide) at the moment while I ponder my options. I have several concerns. The auger clearance will be cutting it close. I didn't want to put the auger assy together just yet, but I will have to before I commit much more time. I can mill it thinner, but then again it needs to hold several hundred pounds, and the auger is close so I have concerns of it bending up closer with time. I sure wish the angle was steeper. Anyone have thoughts about building this better mousetrap?


----------



## Blue Hill (Mar 31, 2013)

I think your concerns about it curling under the weight over time are well founded Dell. I don't have any experience with HDPE sheet goods, but I've worked with the pipe quite a bit over the years. One of the things that's always amazed me is seeing miles of this pipe, with 1/2" or 3/4" wall thickness laying on the ground along the road waiting to be laid and it snakes all over and follows the contours of the ground as if it were a rubber hose.
I don't think you'll get away with leaving too much off the edge of the housing, but an inch or so should be ok. I'd try to keep it thick too, if I could.


----------



## dbert (Aug 25, 2013)

I set the auger back in for a fit check. It clears by about .250 in. Still close enough to be a concern. The skids on this machine were completely worn away. In fact this side in the photo the skid was missing so this is a what one would consider worn a bit beyond limits. The sharpie line is an extension of the former wear limit. You can see the location of the threaded fastener holes. Id like to add say 3/8 thickness below this sharpie line for future wear but that hangs the edge out there a long ways. Just don't know if this will work. It is a worthwhile thought. Just don't know what would happen. Worse case scenario... I bust shear bolts and waste my time? 








one more








x


----------



## TimY (Oct 27, 2013)

Del,
I think I have a possible solution for you, but a few? First that piece looks 3/4" to 1" yes no? Second that black piece next to your calipers I'm assuming that's a retainer strip of some sort does it go on top of the HDPE or on the bottom of auger housing and is it steel or something else. Now I'm not bragging and I'm not the foremost world expert on this stuff but I've worked with it a whole lot for 17 years I can tell you what it can do,which is long list and what it can't which is a very short list and if I can't answer something the experts are right down the road and a phone call away. My way of paying back for your help. Oh yea how long is it and what was that originally an actual cutting board or a piece plastic some had used for one. I know that sounds like a fine point but is does make a difference.


----------



## dbert (Aug 25, 2013)

The yellow material is only 1/2 inch thick. It was an unused cutting board my niece brought home from the restaurant she manages. 
I cant even guarantee it's HDPE.
It looked like this (including the little hook).
San Jamar CB152012YL 20" Width x 15" Height x 1/2" Depth, Yellow Cut-N-Carry Cutting Board: Amazon.com: Industrial & Scientific

The metal strip on the floor is the original steel scraper bar. It was on top where the plastic is now sitting. I'd estimate it to be 1/8 inch thick and perhaps 1 inch missing (worn) from it's original width (depth). As you can see it attaches with countersunk bolts. I have concerns about how well the plastic will hold up to a countersunk type fastener.
I was hoping to use it as a non marring edge like they have for snow plows, but it's not just vertical enough.
Here is a pic of everything when I purchased it. See the scraper bar on the ground?


----------



## Blue Hill (Mar 31, 2013)

Del, if you have a place that sells industrial conveyor belting and the assorted accessories in your area, they should be able to hook you up with some elevator bucket bolts.
http://upload.ecvv.com/upload/Produ...64886_Elevator_Bolt_Bucket_Bolt_m6_M8_Etc.jpg
Made for bolting soft material (like belting) to a hard material (like an elevator bucket) they have a big flat head and are barbed (best for what you are doing) or have a square shank like a carriage bolt. The head will suck into the HDPE and leave you with a nice flat surface. Google elevator bucket bolts and you will see what I mean.
Larry


----------



## TimY (Oct 27, 2013)

OK If it came from a restaurant it's probably virgin HDPE (no fillers) about as tough as that
stuff get's. With the number of bolts you have will keep it straight and flat. Heat will make it flex cold not so much I've used it for shelves, and fixtures in industrial freezers. Beaten a frozen out of the ground without breaking. Once the I don't know, wasn't me person that lives in my house left a large expensive board we used to use for cutting pizza in the oven. Then the wife went to preheat the oven. After the distinct smell of burnt army men hit we got it out of there no longer any good for a cutting board it made a bunch of other stuff for me. Had to cut around the wiggles in it. 
The only thing you have to allow for is extreme temperature movement give the bolt holes a tiny bit extra diameter I don't think those bucket bolts will because your screwing them from the top into the threaded housing but if I remember those bolts were size of a 1/4" carriage bolt depending how far you have to counter bore you should be fine. I wouldn't worry about the weight on the hdpe. I'll PM you a drawing see if that will work. I would have liked to see it a little thicker. But you got little to lose.


----------



## Blue Hill (Mar 31, 2013)

The bucket bolts don't require any countersink Tim. The heads which are thin to begin with, will suck in to the HDPE and be flush with the top surface.


----------



## dbert (Aug 25, 2013)

Thanks Tim
Got you PM. Will PM back
Larry
That bolt looks perfect but I don't have room for nuts on the bottom. In the photo of the underside above that thicker bar you see welded on is tapped/threaded. I think they are 8mm threads. Fasteners will have to screw in from above. Anything added below that would lift the scrapper.


----------



## TimY (Oct 27, 2013)

I looked at those the reason they suck down is that you'redrawing them into the plastic with the nut. he has to screw them down into a taped hole in the housing from above for the lack of a better term the nibs would therefore interfere with that procedure he's got to use some sort of what I call a button machine screw it looks like an almost carriage bolt with an internal hex hole for a allen or torex or star wrench in the head. the only one I saw that you could do that with had a slotted head for a flat screw driver. There is a reason you hardly find a slotted screw these days. But those are really cool bolts I just thought up about a dozen uses for them for what I do. Using them on the clearance kits was only about fourth on the list.


----------



## TimY (Oct 27, 2013)

My typing sucks by the time I get words down everybody get there before me. Still really cool bolts.


----------



## Blue Hill (Mar 31, 2013)

Oh crap! . Sorry guys, I didn't realize that they had to be screwed in. Note to self, pay more attention to the previous posts.


----------



## TimY (Oct 27, 2013)

we've all done that. I just thought up more uses for those bolts thanks  Tim


----------



## dbert (Aug 25, 2013)

Speaking of bolts, I need to remember to order some cheap a$$ grade 2 bolts online (while i'm ordering these countersunk bolts). It's what is called out for my shear bolts and I cant find any locally. Grade 2 bolts have no marking on the head. I didn't look high and low, but you wouldn't think they would be hard to find. I'll order spares.


----------



## TimY (Oct 27, 2013)

Fastenal? Got a few out your way


----------



## dbert (Aug 25, 2013)

They're right at my exit. I'll go check it out. Thanks.


----------



## Spectrum (Jan 6, 2013)

I think you want to be a lot thinner or better yet steel and give up on scraping with the machine.

Gilson usually referred to the part as the cutter bar and that's just what it needs to do. I needs to slice near the ground to let the machine progress forward, low profile and sharp. The machine should be riding on the skids. The skids should be set so the machine does not snag on pavement irregularities or sling gravel all depending on the property. The cutter bar extension should be minimal to limit leverage. Set this way the cutter bar should be a forever part.

Letting the cutter bar scrape will result in all sorts of cracking and bending of the bucket. The jarring that happens with each snag is hard on the machine and operator.

Obviously some will want to scrape to nothing and that's their prerogative but IMO it's counter to best practices and equipment damage usually bears this out.

Pete


----------



## dbert (Aug 25, 2013)

I respect and appreciate your opinion Pete. I'm a huge fan.
I was hoping to lead this edge with similar height radius lip shoes to smooth the transition over the expansion joints and whatnot. What I was going for was something like this that they make for plows with the intent to be a sacrificial material that cleans well without marring up the surface. 








This particular blower is a 600 lb machine that has spent its share of time not floating the scraper as the skids were complexly worn away when I got it. It does have a hydraulic lift and a tug on the lever can give me ground clearance if I want to hover. If snagging and jarring becomes a concern or it just doesn't work out I can put the metal scraper back on.


----------



## TimY (Oct 27, 2013)

Del I really think your on the right track. As far as I can tell those bars on those plow blades are made of the same stuff. I know it's kind of a different concept with the plow blade but the idea should transfer over to your situation quite well. Hopefully you got to look at my drawing. But I think that HDPE would be Less stress on the bucket than steel because of it's low friction properties that and it won't rust.


----------



## dbert (Aug 25, 2013)

Tim
Did you gat my last couple private messages? I'm having problems accessing the drawings.


----------



## dbert (Aug 25, 2013)

So TimY had a great idea to attach this with better support. Cut a slot in the HDPE and sandwich the steel lip in the poly. With the lower lip now under the steel edge it's very sturdy. 









It wasn't long enough to make in one piece but I just made it in two half's. I also made it wide enough to go flush to the outside edge.









Before I bolt it in place I need to come up with a final length. It's still currently longer than it really needs to be.









If I cut it off at the sharpie line, I'll have 1/2 inch of material to wear away to reach the point it was before. I don't know if that is one season or twenty seasons so I am still trying to decide how much to cut off.








Thanks again Tim
Next up is the side skids.


----------



## Blue Hill (Mar 31, 2013)

Nice work Del. Thanks for the update.


----------



## SweetD (Dec 6, 2013)

Great stuff. Whatever you do, take measurements (and maybe even make a couple more parts) before you start using it. Nice to have some pre-made replacements in the garage so you don't really have to worry about replacing them when the time comes!

Dave


----------



## TimY (Oct 27, 2013)

You're very welcome Del VERY happy to help out. Looking great we'll put all our heads together on those skids. Tim


----------



## dbert (Aug 25, 2013)

SweetD said:


> Great stuff. Whatever you do, take measurements (and maybe even make a couple more parts) before you start using it. Nice to have some pre-made replacements in the garage so you don't really have to worry about replacing them when the time comes!
> 
> Dave



That would have been a good idea. I just hacked at them with a table saw until it fit. It was cold in the garage when I cut them so I was not taking my time. My saw does not have a tight fit around the blade opening. Cutting the kerf up the center was the worse. There is some melting build-up when you cut deep and the burr that forms snags on things. This melt scrapes off easily like 10 seconds after its cut but made it hard to have precision cuts with my cheap table saw.


----------



## TimY (Oct 27, 2013)

Oops sorry Del I forgot to mention that part. I haven't come up with a decent way around that. I'm so used to that, that it kinda slipped my mind,the closest I've gotten is to wax the blade but it doesn't last long and is almost as much hassle as it's worth.I use brake cleaner to get any gummy stuff off my blades. I tried wd-40 kinda worked but I spent more time cleaning the saw( can't get any of that on wood) than the job took I f anyone has to make a cut like that take multiple shallow cuts and clean out the slot after each one depending on the grade it can jam during the cut so be ready to turn the saw off. Again Del I should have remembered to mention that. Tim


----------



## dbert (Aug 25, 2013)

It didnt seem to want to stick to anything but itself. It wasn't really sticking to the saw or blade. Perhaps because it was so cold. I did take several passes, and I could scrape the melted stuff right off the cut piece with one swipe of the edge of the table saw table. Maintaining any constant depth was a challenge, but I was only making room for piece of steel to fit inside of. I kept pushing the tail too deep when I'd finish the cut because there was nothing under it at the end.


----------



## Kiss4aFrog (Nov 3, 2013)

The trick with cutting it might be like plastic. You want a really sharp bit and a slow cutter speed so the cutter is cutting and not burning it's way through. Learned that doing switch installs in dashboards. Sharp bit with a Dremel turned way down and It'd cut clean.
Being in a cold garage & cold material might have helped it cut cleaner !!

That's a great install and really good pictures to help us follow along. On older stuff where the scraper isn't easily available this would be a very worthwhile improvement.


----------



## micah68kj (Oct 8, 2011)

Blue Hill said:


> The bucket bolts don't require any countersink Tim. The heads which are thin to begin with, will suck in to the HDPE and be flush with the top surface.


I was going togeet these if the skids I made were slipping. I just used regular carriage bolts and they're working fine. Nothing has moved so far.


----------

