New "high tech" dust foot, opinions?

[Sk8MFG]

I have a friend in town who works with plastics. Injection molding, 3d printing, thermoform etc etc...

We got to talking about my dust collection setup on the bot, which is a kent style boot. It works reasonably well, but has huge room for improvement.

After a few brain storming sessions, we've come up with a design for a new boot which will be going on my bot.

The boot has a 4" outlet, clamps to the base of the spindle and can be matched to different spindle diameters. The skirt is mounted to the boot with magnets to aid in easy tool change. The brush is also easily replicable.

This design focuses airflow around the tool which will reduce the loss of vacuum when the skirt hangs over an edge etc. It should really suck.

Once we're done testing on my bot, we may make some more. I'd love to get some feedback on it. Any suggestions or comments would be welcome.

DSC01425.jpg

[Justin G]

I made my own dust foot using acrylic before finding the kent shoe on the forum. It was the exact same concept: magnets, clamps to the spindle, removable brush skirt, etc. Learned a few things before buying my kent shoe. The dust foot that came with my shopbot was not as awesome as the rest of my big blue. Shopbot has since updated the design and has the new ones for sale, they LOOK awesome, but personally have no experience.

One thing about the kent is that it is tight in some area and not in others. I position my clamps perpendicular to the long axis of the dust shoe so that when I am doing a profile cut, the "housing" of the dust shoe does not hit my rockler clamps that are about 2 1/2" high. I think the housing body should be MUCH tighter to the spindle with the brushes protruding out at an angle. Since they are flexible, they can accommodate larger diameter bits and when they brush against clamps or other obstructions, the brush will fold naturally. I'm thinking something like a 45 degree angle.

The hose should definitely go up in front of the spindle in my opinion. With it going to the rear, you lose Z travel or at least have to think about it, and that is one more thing of 1,000. I had an idea to make a tight fitting shoe that would have the hose run around the body of the spindle so that is actually sucked air THROUGH the cooling vents. You would have to reverse your cooling fan, or disable it while DC was running, but I think the added air would help to cool the spindle as well. Small chicken wire could prevent larger chunks from getting lodged in there. If the brushes were large enough to fit a 2 1/2" diameter bit with some slight added clearence, I would be happy.

Also, I made an arm which connects from the back bracket and wraps around to the front, this takes the weight bearing off of the Z axis and has it resting on the Y car. Which should be a lot less gravity to contend with. That should be included, again IMO. I'll post a picture shortly.

Sometimes with doing engraving onto a 3d work, I have to go deep into the carving and I just cant do that with any high angle walls, or tight spaces with the kent. Another reason to make it tighter to the spindle. Of course I could remove the foot temporarily, but I dont and won't and usually just hope It doesn't crash into anything, finger lays in wait on the spacebar...


here is the new dust foot:
http://www.shopbottools.com/ShopBotD...%2010%2029.pdf

[Justin G]

IMG_8305.jpgIMG_8306.jpgIMG_8307.jpgIMG_8308.jpgIMG_8309.jpg

pictures of the arm as promised. Its not pretty but works for me.

[Sk8MFG]

Great, this is just the kind of feedback we need. Keep it coming!

Your setup looks very similar to my current one. I'll pitch the idea of having the port going vertically and see what we can do. Only problem I see of going up the front and tightening it to the body is it would be limited to only a few spindles. With the duct going out back, it would fit on any spindle.

The image I posted doesn't really show the clearance too well, but it should provide more clearance than your(my) current setup. The duct is set above where a kent main plate would be. As for pitching the brushes outwards, that may be a good way to keep the brushes from getting cut up. We will be playing with different brushes, most likely using a stiffer brush to keep the bristles from being sucked into the tool.
The diameter of the brush would be able to fit any bit you can mount. I have a large cove bit, which will be used with this boot. I think it's 4" wide or so.

I'd love to be able to make a few of these for fellow botters. I have a feeling it's going to be quite the nice bit of kit, and won't break the bank.

[Kyle Stapleton]

Do you think this would fit on a bot with air drills?

[donclifton]

I made some out of MDF, Because the brush is much smaller I get more suction. I have inserts to raise and lower my brush for longer or shorter bits.
Thanks
Don

[Sk8MFG]

Do you think this would fit on a bot with air drills?

On a PRS with an air drill, if the dust port was coming out the back... probably? If we had it come out the front like the photo below, I don't think so. *edit. I suppose using this configuration you could have the duct off to the side of the spindle vs straight ahead. That may clear an air drill.

Vertical Head.jpg

I made some out of MDF, Because the brush is much smaller I get more suction. I have inserts to raise and lower my brush for longer or shorter bits.
Thanks
Don

Yep, very similar principle. Reduce the area to increase the suck. We'll be running some simulations as well as lots of testing to see how much of an improvement in air speed our new design gets. See how it stacks up to a kent style, and one like your's Don.

[srwtlc]

I like your proto. Some thoughts/opinions... I prefer it to come out the back because of how my tool is set up and for ease of tool changes from the front (front for me is the spindle side). Coming out the front along with the hose, puts it in the way of tool changes. Having it attached to a drop bar in the way that SB does allows for more clearance whereas mounted on the spindle nose takes away some of that clearance distance. One way to gain some extra clearance is to make the connection on the foot be oval shaped. On the older SB ones, they would flatten the 3" hose and shove it in the back of the foot. This was a poor way of attaching it and also left a leaky connection. I took a piece of PVC and heated it until I could form it into a flat oval shape that fit into the back of the foot and then sealed it in place with expanding foam. This allowed a 3" hose to be easily slipped on and clamped in place. This also allows for full Z lift yet.

If connecting from the front, it will not allow drills to be used (SB's new one apparently wasn't designed with that in mind either). Coming from the side will interfere at each table leg location and if on the motor side, will have to go out and around it. Might be able to get away with a angled connection that would allow for a drill attachment and clear the legs.

You could use a long drop bar in same way that the new SB one does. That alone alleviates the small thumb screw down/behind/underneath that is hard to get at and not always in the right position.

Here's a shot of my oval PVC.

[coryatjohn]

I would have to go with the "hose in the front" crowd. I originally had the (crappy) SB dust foot and tried using it for a while but having the hose come out the back just kept being an issue. Once I installed the Kent foot, with the hose vertically mounted in the front, it worked out great. I have a 5" hose from the DC and a 4" hose coming out of the foot. The smaller hose slides in the larger one (with a gasket at the top of the smaller) so the joint is quite flexible and doesn't have to bend to get longer or shorter. This works quite well with my 12" Z machine. It also offers very little resistance to the Z axis.

One thing that may be an issue is the volume of air that can be moved if you constrict the opening of the host like you have in your prototype. The Kent design maximizes the air flow. I have a wicked good dust collector so it sucks mighty and I'd hate to have anything get in the way of that flow. Also, obstructions to the flow would cause one big howl. I don't need any more noise in my shop then I already have.

I think the Kent design is pretty good. I've had no problems changing bits or having it collide with clamps. I have both the 2 and 3" brushes with an extension so I can adjust it to however I need for a particular cut. I agree that 3D work is a problem, especially using the indexer. I just go without dust collection and use a manual vacuum to keep things from getting too messy. I don't do a lot of that so it's not a problem.

[kurt_rose]

Very interesting to say the least. I work with a lot of Extira and we all know how toxic that is. Better dust collection always gets my attention. Looking forward to seeing where you go with this. I've been very happy with my Kent, but there is always room for improvement.