How NOT to design a dust catcher

Posted by request of @CurtisCummings since I brought it up in another thread.

I wanted to roll my own vs. buying, and have a 3D printer so took the challenge as practice designing. NOT an ME by trade. Goals I was after was a) mating up to existing Rockler ‘small tool’ dust hose, which I have routing to a larger diameter hose fitting against the wall behind the machine to my 2HP dust collector for my cabinet saw, b) wanted it off the side of the mount since I thought all the big ones looked like they weighted the Z-axis ‘down’ in front too much (potentially tilting the bit in the YZ plane…I’ve done nothing to improve rigidity of my X rails yet), and c) I was trying for something I didn’t have to remove to change bits, could just loosen and slide down a tad, and then retighten. It’s also more of a ‘fixed’ dust catcher design intended to set at a clearance height above the bit tip vs. having plastic wipes or brushes.

So, the ugly truth:

The top ring is fixed and just there for extra stress relief to the hose fitting in the part below, it screws right into the threaded hole in the router mount and never has to be altered. The bottom assembly has that vertical shaft and similarly pinches to the router mount with a 4mm screw. If I remove the hose I’ve got a split in the round mount for the hose so I can access that hardware easily to loosen and slide down out of the way, to change bits (the router lock button is not blocked) , then return to the desired height and push the hose back on. The shoe itself is printed as 2 pieces, a bottom that’s kind of boat-shaped with the circular bottom aperture, and a lid with the vertical shaft and hose attach point, then I just cut the clear cover out of a piece of waste plastic I had laying around from something else (hence the writing barely visible on it.)

As far as dust catching it actually does really well - even milling foam which as you can imagine is a static-ridden mess, I get no dust. It’s also super lightweight and the expandable hose tension probably has more impact on the actual movement resistance than the shoe does. But it has some definite flaws. Being off to the side, it restricts my travel to the left (but it’s sneaky…if I do ‘homing’ the machine homes Z first so this raises above the rail in most cases…and then crashes into it if I try to drop Z before remembering to scoot over in X for clearance. D’oh! Probably currently costs me 2 - 2.5" usable X axis distance at minimum)

The vertical mount part is also printed totally the wrong way - I should split this off as a separate part and print that flat to the 3D printer so it doesn’t split so easily between layers. It look obscenely glossy in the image because I coated the whole thing with epoxy for a little more strength and it’s still fractured (thanks to hitting the rail of course).

Works for now but preparing another go-around at a unique design. Will likely try to mount to both sides of the router mount as everyone else is doing to center it and get more strength, also so I don’t cost myself X travel. Maybe split the airflow up both sides of the router to one hose fitting pointing backward at the top to keep it all in the front facial ‘footprint’ of the X carriage if I can. Also like that this doesn’t extend below the bit at all so the only cost in Z travel is currently that I didn’t cut the hole in my plastic cover big enough for the collet, although of course the higher this gets relative to the tip the less dust gets taken.

So far I"m out about $0.95 worth of ABS filament, a little electricity, and $2 of epoxy (the 4mm hardware is reusable), plus a fair amount of design time and mental humiliation, so I’m not beating myself up TOO badly. But yeah, not a winner.

Laughter welcome.


no laughter required or merited. props for making something! more props for being bold enough to share. what printer do you have? share the designs if you can/would so others can benefit and iterate.

1 Like

Printer is a truly antique Solidoodle v2 “Pro”, heavily Frankensteined at this point (glass bed, Lawsy carriages, rerouted filament path, … E3V5 extruder in the wings waiting to be installed one of these days). I mostly print ABS.

This design is truly not worth sharing. That vertical shaft is horrendously weak, and I don’t even have the circular dust collection centered properly around the bit without spacers. But as it evolves better I’ll definitely eventually upload to Thingiverse or somewhere else useful and link here.

That’s not at all what I was expecting. The way you talked about it I was expecting a MONSTER lol. Actually it a no nonsense practical design. You mount yours the way I mounted mine. Screwed right to the spindle mount. I came off the mount with a straight bracket to the side of my boot so it comes off the front. The only problem with that. When I cut deeper 3D contours it will bottom out on the work piece.
I’m currently in the process of some “heavy” mods and plan to have a new dust boot mounted directly to the X carriage That way the Router can move independently.

Thanks for posting!

1 Like

Make sure you crack some of the fittings in the system. a 4" 2hp duct collector wants to move much more air than the Rockler hose can. The fan stalls in the DC, and so you loose throughput. If you partially open a wastegate in the system, the fan is moving the correct amount of air, and the smaller hose works better. Sounds counter intuitive, but it works.

1 Like

@CurtisCummings you’re welcome. I do like the idea of mounting off the X carriage so it doesn’t move up and down with the router. Trade off less dust absorption the lower the router is working for not mucking up your workpiece or catching and making you miss steps. Potatoe, Potahto.

@Andy4us, thanks for that. I do have a Y adaptor at the impeller with a cap end on it, might just go ahead and hook the other 4" hose to the cabinet saw instead of capping the 2nd Y path…since that’s drawing inside a closed base thru the saw slot, might provide just enough ‘bleed’. But suction already seems pretty good (good enough that when I got overly aggressive on making tabs small on cutouts I was having to pause the work to turn off both router and impeller to rescue the cutout and the job).

My collector is an older Jet design with a thick plastic 24-gallon sized or so bag below and the big corrugated inside metal cannister ‘Bench Dog’ filter top half with the spinner paddle handles for knocking the fine dust off of it, instead of just a fabric type bag. Had it for over a decade and been very pleased with it for all other woodwork. Still debating rigging up a small cyclonic catcher between the Xcarve and it to keep plastic, foam, other cuttings out of my general sawdust. (Metal perhaps too but don’t see myself cutting that anytime soon.)

1 Like

Only 95 cents for the ABS to make that? I would have guessed 10 times that amount, ABS must be lots cheaper to use than I thought it was. One of the reason I was holding off buying a 3D printer was the ABS cost.

When I last looked at the cost I remember the ABS being about $50 to $80 per 5 pound reel. Maybe I am just over estimating how much 3D printed parts weigh.

I might be underexaggerating a little - I did have a failed print before the one I used, that just plain didn’t fit (bad measurement on my part). But typically a spool is 1kg (about 350m I think?) of 1.75mm ABS, for these days $20-35 depending on color, quality, etc.

I bought my printer years ago along with a spool of red and one of black, and have since added another spool of black, clear, and glow-in-the-dark blue from another source. I had to pitch the original black because it was poor quality and kept clogging…but I’m still using that first red spool. Granted I don’t do “production” of anything, just one-off prints, but I’ve not used up ANY initial spools yet.

The whole part has 1.2 - 2mm thick walls in most places aside from the vertical support, since it’s mostly a hollow shell, and weighed I think 50-60 grams or so before I mummified it in epoxy. Aside from the part the hose goes over where I went thicker you could crush it in your hand easily (it might poke you a bit but it wouldn’t resist). Even when I’m printing large somewhat solid looking parts much of the interior is 20% or so plastic in a hexagonal or rectilinear framework pattern, the rest is air. You do like 3-5 layers (0.3mm nozzle sets the effective thickness of a layer) for outer shells.

ABS ain’t the cost…it’s the sunk cost of the printer, the hassles of figuring out HOW to print (orientation, where to break parts, etc.), electricity, and frustration.

@RichardRemski Thank you for the explanation