Grizzly wide belt sander dust port

[KelbyVP]

My situation: I have a 3-car garage, and my power tools are in two bays of that garage. I am currently using a 2 HP Laguna Cyclone, but I'm getting ready to upgrade to a ClearVue 1800 with the 16" impeller upgrade. (I'm waiting for the next sale.) I have 6" mains. While preparing for the cyclone upgrade, I'm doing an inventory of tweaks to my tools so that I can get the most of out of the upgrade.

One of the tools I'm concerned about is a Grizzly wide belt sander (G0527). Unfortunately, my shop layout dictates that this tool sit far enough away from the Cyclone that there's about 20' of ductwork and one gradual 90 (made from two 45 elbows) to the drop. I then have a wye with a 4" connector for the drop to the Grizzly. Unfortunately, Grizzly put a single 4" dust port on the outside of the machine. Although I would like to upgrade this to a 6" port, Grizzly also welded an assembly inside the machine that takes this port and funnels it to the location where the dust should be coming off the belt. On the one hand, I think it's great that they are trying to funnel the airflow to the precise source of the dust. But on the other hand, limiting the system to a 4" port really sucks. Bill Pentz's calculator shows a 4" tapered port results in a 3.14 SP drop! Ouch! By the time I add 18" of 4" flex to connect this to the wye off my main run (another 2.34"), and by the time I throw in 20' of 6" ducting and a couple gradual bends, with 1.5' of 6" flex to connect the cyclone to the mains, I'm over 13" SP. Unfortunately, moving the machine or the dust collector is not an option. I would hate to have to upgrade all my mains from 6" to 7". Any other suggestions? Will the 1800 draw enough air through this setup to keep me up near the 1000 CFM I would love to get?

Pictures

Here is the 4" dust port:


Here is the funnel inside the machine that goes from the 4" dust port at the top down to a sort of "sweep" where the belt is doing its work:




A better picture of the sweep at the bottom of the belt:

 

[jsbrow]

KelbyVP,

For some reason I was unable to open the photos accompanying your post; could be the web site or my computer. Anyway, since I could not get a good look of the machine I will probably be of limited help. I did look at the parts diagram from the manual for your machine and have experience with a wide drum sander, which has a dust shroud to channel dust to the 5” dust port on my machine. Therefore, I think I have some idea of the problem you are facing.

The first idea is to take the upper housing to a machine shop and have them cut in a 6” dust port. Obviously this would be an expensive approach and if the machine shop does not get it right, matters are way worse. But if they do a good job, it could solve the problem.

The other idea is to leave the existing 4” dust port and add a second 4” dust port. This is the route I took on several of my machines. One advantage of this approach is that allows for placement of the second dust port so that a dead spot where dust can otherwise accumulate can be eliminated. The critical part of this dual 4” port implementation is the transition from the dual 4” ports directly to 6”. A 4” x 4” x 4” wye transitioned with a 4” x 6” reducer would restrict air flow. I used a Woodstock T23830 - 6" x 4" D/C Adapter purchased from Grizzly (Item# D4240). It connects the dual 4” ports directly to a 6” diameter. Dual 4” dust ports offer about 90% of air flow of a 6” port based on cross sectional areas.

The second 4” port could perhaps be tapped into the dust shroud of the machine and extended to the outside of the machine cover. But even a right angle drill outfitted with a 4” hole saw, the limited space in which to work, could preclude this option.

Locating dust collection outside the machine cover would be another option, although I am not sure how effective dust collection would be. On my drum sander and when I used a ½ hp dust collector before my Clearvue upgrade, I noticed a lot of uncollected dust resting on the workpiece as it emerged from the outfeed side of the machine. Therefore I would think this would be a good location for external dust collection. I would think that a 4” floor sweep fitting, modified at the throat to give the width required could be mounted on the outfeed side of the machine. A piece of rubber, perhaps from a bicycle inner tube, could be attached to the wide throat of the floor sweep to make soft contact with the workpiece and offer some raking of the dust. This gasket could help direct air flow and loosen some of the dust that seems to stick to the lumber.

 

[bababrown]

I also am not able to open the photos.
bababrown

 

[cvcsupport]

Please note - we have now updated the forum so that photos are visible to unregistered users. These photos should now be visible to all.

 

[jsbrow]

cvcsupport,

Thanks! When I tried to view the photos earlier today I did so both without and after logging in; in both circumstances to no avail. Whatever you did works for me; I am now able to view the pics.

KelbyVP,

I can see from the photos that tapping into the dust shroud is not a very workable plan. Since I assume the sanding belt loops over a drum at the top and threads down and over a pair of drums on the infeed and outfeed ends of the machine (the sanding belt forming a triangle), perhaps a 4” hole can be introduced in the outer wall of the sanding belt housing on the outfeed side. I would think there may be a little more dust captured if the port is mounted high. My thinking is that centrifugal force as the sanding belt travels over the upper drum would fling dust off the top of the upper drum where it could be captured.

 

[KelbyVP]

jsbrow, those are great suggestions. I think you are on the right path. The dust coming off the belt at the bottom will get pulled by the existing port, and the dust that hangs on the belt should get pulled up toward the top of the machine. I think if I can get another port on the top or toward the outfeed side near the top, that should create the last little bit of airflow needed to get great dust collection on this tool. Thanks!

 

[KelbyVP]

Well, I have some new info. I bought a cheap anemometer and checked my airflow at various points in my system. I know this is not a super precise way to measure airflow, but it gave me some interesting insights. I'm testing by opening my ductwork at various locations and putting the anemometer in the center of the duct with the duct wide open.

First, my DC is getting around 2600 fpm at the DC intake. That's 520 CFM. That's not spectacular, for a cyclone that is advertised to get something close to 1600 CFM! It just goes to show that the advertised ratings are nowhere close to accurate -- we all know you can't get 1600 CFM out of a 2HP cyclone, but 520 CFM is much worse than I expected.

Second, I measured the airflow at each tool port to see how much airflow is lost due to ductwork. My very non-scientific testing method was to remove the flex hose from the tool port and measure the airflow at the end of the flex hose that would otherwise attach to the port. So these measurements do not take into account loss due to the tool hood or anything inside the tool. I was pleasantly surprised to see only modest CFM loss due to the ducting. Most are getting 450-520 CFM. That's a CFM loss of less than 15% due to ducting. If I measure before the flex hose (i.e., right before the drop), the loss is closer to 5%, so most of the loss is due to the flex hose between the wye at the drop and the tool port. That's great news.

My worst tools are my planer (325 CFM), tablesaw (271 CFM), and my wide belt sander (350 CFM). The planer and tablesaw are completely my fault -- way too much flex hose. I need to use more spiral pipe for those runs, and I will fix that. The wide belt sander is a function of the 4" port, as described above, so that would require a port modification. But the surprise here is that, even on the wide-belt sander, I'm still only looking at less than a 1/3 CFM loss due to ducting and reductions to port size.

Another thing I learned, spending some more time at Bill Pentz's site: A lot of the reason for his CFM/FPM recommendations is that he's assuming the dust collection at the tool needs to collect dust throughout a fairly large sphere, because the tools are usually not designed to direct the tool-generated airstream into the dust collection. Looking again at my wide belt sander, even though the cross-section of the dust port "funnel" is only 20 square inches, that 20" is directed straight at the airstream/duststream generated by the sanding belt, and it is extremely close to the point at which the sanding belt makes contact with the material. In that sense, it's actually pretty well engineered. Which may explain why my measly 350CFM does a surprisingly good (albeit not great) job of getting the dust. 4" is not ideal, but it may not be as bad as I first thought.

Overall, this data suggests that the biggest problem in my system is probably my underpowered cyclone. So, I started poking around to see what kind of airflow improvement I might expect moving from a 2HP like mine to a 5HP machine like the Clear Vue. I ended up comparing some of the fan curves for O'Neida's 2HP and 5HP models, on the assumption that they might give some clue to the improvement I might hope for, and I was a bit shocked. I know this is not extremely accurate and scientific, but I think it is very eye-opening.

The O'Neida fan curves show that their 2 HP model gets 350 CFM at 9" SP (similar to what my Laguna gets at my wide-belt sander). The fan curve for the O'Neida 5 HP model shows that it gets 900 CFM at 9" SP -- almost triple. Wow.

Now, I don't have the 2HP O'Neida, and I'm not going to a 5HP O'Neida. I'm going from a 2HP Laguna to a 5HP Clear Vue. But I wouldn't be surprised if I get a greater increase going from the Laguna to the Clear Vue than one would get going from a 2HP O'Neida to a 5HP O'Neida in the same product line -- the O'Neidas are similar other than motor and fan size, while the the Clear Vue design is also superior to the Laguna in many other ways.

All of this suggests that (a) my ducting is pretty good already; (b) my tool ports are not ideal on some tools; but (c) my best path for improvement is probably to focus on upgrading the DC. So, my plan for now is to hold off modifying tool ports until I get the DC upgraded, and I can tinker then if I still think it's warranted.

I'll document my progress and improvement for anyone who might find it helpful.

Cheers.

 

[MarkFerraro]

Don't overlook the efficiency you will pick up with a much better air filter system. Air can't move unless air can get out of the cyclone/Dust collector. As I've stated in other posts, increasing filter bag size by using custom sized singed felt bag on a dinky ShopSmith DC had great results. The twin Wynn filter cartridges that come standard with the CV is a huge step up in efficiency.

Don't be afraid to cut out your dust ports on your machines and upgrade them to a full 6 inches. My Delta Table Saw had a five inch opening covered by a plastic 4 inch port. I removed the port, cut the hole to 6 inches and made my own hook up with 6 PVC pipe. Even with a 3 inch port to my Shark overhead blade cover, there is no saw dust inside my table saw with the CV DC. I have a homemade dust/chip hood for my Makita 15 7/8 inch planer. I cut two air inlet holes in one end that I can open or close like shutters with a 4 inch connection to the CV DC. The difference in dust/chip pick up is day and night. Sometimes its not the size of the connection as much as being able to add make up air that adds dramatic results to the dust collection.

Congratulations on your inventiveness in trying to maximize your dust collection. You are discovering what must of us have experienced: less flex pipe, larger inlets and better filters delivers tremendous results.

Good Luck!