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View Full Version : UHMW and chip collection on a table saw?



gundog
03-01-2008, 02:01 PM
I just bought a Delta 50-760 at a local supplier and got it home and hooked it up to my Grizz 1023 saw. It does not have enough suction to evacuate the plastic chips I make when cutting UHMW.

I have the dust collector set up with 10' of 4" clear vac hose connected to the saw the other port of the 4" Y is plugged.

Let me back up my story by a month or two. I had a Ryobi BT 3000 TS and I cut a little UHMW with it, it worked OK but was a little underpowered to cut 1.5" UHMW. The Ryobi would cut it but I could hear it was really straining the motor. The saw worked great for chip collection though just using a shop vac. The Ryobi has a nice shroud on the under side of the blade with a 2.5" dust port attached and it worked really good to pull the plastic chips or swarf. The down side was constantly cleaning the vac.

I bought a new Grizz 1023 TS for the greater HP and it cuts great but because it has such a large cabinet the dust collector can't develop enough suction to pull the chips out. The UHMW must be pulled out as it is cut or it creates large string balls that clog the system and can cause kick back when the blade grabs a ball of this stuff and forces it into the kerf of the cut. The cabinet saw lets the stuff fall in the cabinet until it is large enough to fall towards the dust port and then because there is so much it imediately plugs the system.

I am not sure what to do at this point. I feel like it would probably take twice the suction the 50-760 is putting out to pull it out of the cabinet fast enough to stop the buildup. I am wondering if there is enough room to construct a shroud like the Ryobi had and go back to a shop vac. I am not sure if there is enough room inside the cabinet to not restrict the saw from being able to fully tilt.

The sales guy I bought the Delta from thinks I should try and construct a shoot out of melamine to funnel the stuff to the dust port inside the cabinet of the TS.

I also cut the same material with a panel saw that has a shroud on the blade with a dust port on it, it is hooked to a shop vac and has no problem with pulling the chips out. The blades on both the panel saw & TS are Forest no melt plastic blades so they are making the same chips.

I bought the Delta 50-760 because it has been rated best in that size DC by several woodworking magazines. I have posted this question and problem on a woodworking forum too but because it is specific to machining plastic although with a wood saw I thought maybe someone on here has already figured something out. I make hundreds of parts a month out of UHMW so I need to figure something out.
Mike

2ManyHobbies
03-01-2008, 02:39 PM
Is the slot for the blade reasonably sized? (not too large or too small)
If so, with the saw off, drop the blade all the way down (or removed it) and completely cover the slot with a non-permeable material to see if the dust collector is starved for air at this point.
If so, then you just need better chip direction under the saw.
If the dust collector is not starved for air, then you have to find and block other air entrances that are not around the blade.
Lastly, would the chips be coming off of the blade in the direction of the dust port, or away from it? I would doubt that it would be going away from it, but it might be one more thing to verify. Obviously, if they stack in the corners instead of being sucked out of the dust port, you will have issues, but I don't know what the inside of the saw looks like to be able to advise on how to best funnel the chips to the port.

Paul Alciatore
03-01-2008, 02:42 PM
I just have a cheap table saw in my shop. It has a completely open bottom so I added a cloth dust catcher across it with an opening in the middle for the vacuum hookup. I attached it with Velcro and snaps. It seems to work well enough with my small Shop Vac.

If you don't "have enough vacuum", that probably means your Shop Vac does not move a sufficient volume of air. The vacumm pressure is not that great with any of them and does not vary much with larger models, just the volume of air moved or re-moved. You might be able to enhance the performance by closing any air leaks your saw may have in places where the dust does not need to be moved from. Try to direct the air flow across the blade area where the chips are being made and then to the exhaust port.

ptjw7uk
03-01-2008, 03:08 PM
Where is the extraction point situated in relation to the blade.
If the point is high enough you could put an extension tube inside the bottom cabinet, remove the top half of the tube so that chipping drop into it also cut a slit in the bottom haldf so the blade runs in it.
With careful sizing and shaping it should genrate enough suction at the right point to extract the majority of the chippings.

Peter

gundog
03-01-2008, 03:27 PM
The extraction port is in the bottom. Here is a picture of a saw like mine the only difference is my saw is left tilting and has a large motor cover box above that port on the left bottom. Look at the size of the cabinet and you can imagine how much area there is to creat a vacum in plus the slot for the tilting arbor gives a huge gap as well.
Mike

http://www.grizzly.com/products/10-Table-Saw-3-HP-Single-Phase-220V/G1023S

This is my saw but it does not show a picture of the port but you can see the extra motor box.

http://www.grizzly.com/products/10-Left-Tilt-Cabinet-Table-Saw/G1023SLW

Rookie machinist
03-01-2008, 03:40 PM
If you are not tilting the table on a regular basis try covering the hole in the saw body where the tilt lever comes out. I have a large piece of rubber I put over mine to seal the saw and allow my dust collector to work better. I also sealed most of the openings between the saw table and the stand.

gundog
03-01-2008, 03:47 PM
I am going to cover that tilt opening I was thinking some of that sheet magnet material (the stuff they use for refrigerator magnets) might work good I wonder where I can get a large piece? I could also use some spray foam around the cabinet to table I do remember the corners having a big gap where the table sits.

Mike

2ManyHobbies
03-01-2008, 03:56 PM
The goal isn't going to be to pull a vacuum on the entire cabinet, but just to promote a healthy airflow from the blade to the dust port to clear chips. Any local home improvement place should have a heavy rubber underlay for tile showers. That combined with magnets, foam tape, screws, or velcro should nicely seal off some of the extra openings. You may find that some additional cross-flow under the blade can help clear chips better than pulling air only from around the blade, but it could take some experimentation to get such a flow running correctly.

darryl
03-01-2008, 04:51 PM
Something else to consider is the dust collector bag- it's probably restricting the air flow far more than what would be required to collect uhmw chips. If the same saw makes fine dust from other materials, you're kind of stuck in this regard unless you can go to a pleated bag of some sort that has a much larger surface area. If fine dust control isn't really needed, go to a bag that's much more open. You might have to make this yourself (have the wife sew it up from a different material).

We have a similar problem in the wood shop- when the bag is freshly cleaned, the system works. About ten minutes into cutting, the pores in the bag are plugged and the effectivness as a dust collector is poor, though it does still contain the fine dust.

What others have said about eliminating air leaks from anywhere around the saw except through the blade opening is right on as well. You don't necessarily need to shroud the blade, just make that area the only place where air can enter the cabinet. If there's an obstruction that's catching the swarf, you may have to instal a deflector there to keep the flow path smooth. Maybe your saw has a provision for a scoring blade in front of the main blade. If so, and you don't use that, you may have a good mounting point for the deflector, and it shouldn't be hard to keep it from interfering with full tilt.

Duffy
03-01-2008, 06:32 PM
I have virtually the same model in right-tilt sold by Busy Bee as a Craftex. A piece of Coroplast corrugated plastic with a strip of manetic tape stuck to it works very well. If you forget to remove it when tilting the arbor, it just slides. I find that there is a huge dead zone in the cabinet and I have a 2 hp dust collector. When I clean out the cabinet, I will get about a bushel of sawdust. Perhaps if you installed a filler inside the cabinet, the transport velocity would increase enough to give the capture that you need.