That’s one of my concerns about the plywood chute. The tab/slot combination has a clearance of .04mm for a close fit, and there will be dog-boning in the final version. The parts will need to be glued together, so this should do some work towards sealing it. If more is needed, a little bit of caulking in all the inside corners should do the trick.
Could you just use a flexible material for that part? piece of thin metal? You could cut slots in the plywood so the metal “slides” in and then you just caulk it up to make sure it’s well sealed.
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I didn’t think of that, excellent idea! In that case, I could actually make the top piece just a piece of 24 ga steel and simplify the assembly a bit.
I say 24 ga 'cause it’s easy to cut with a pair of hand shears, and I have a ton of it lying around the shop >.>
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Alright, fixed up the assembly as per @madgrizzle’s suggestion. Thank you so much, this is a great idea!
As I’m sure it’s what most of you are looking for, let’s start with some pictures:
Section View:
“Front” View:
Attached to the sled:
I changed the sides of the chute to 1/2" plywood, given that the new design has the slot cut into it. I also quickly revised the body of the dust hood to make it easier to cut out of 3/4" plywood and mate with the wooden dust chute. The plexi window still needs to be corrected for the new chute.
The only “issue” I is with the thickness of the metal. I say issue, though I’m not sure this will ultimately be a problem. 24 ga is approximately 0.025", which is significantly smaller than the smallest tool I have, which is 1/16". This would leave an 0.0375" gap, which you can see with the section view. I usually give my parts 0.015" clearance for fitment, so this might simply just be a loose fit. Worst case scenario, it may be worth cutting a second piece or simply jumping up to 20 ga (0.0375" thick).
As much as I love my 3D printed version, I also am starting to like this design too! 
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I’d think some caulk would take care of it. It’s not structural component and would probably be pretty snug anyway since it will want to spring flat.
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Hey @MeticulousMaynard,
I think it looks good. I like the how the flexible sheet makes it possible to create something other than a box. I have some feedback. Hopefully, it is constructive.
One concern is how the flow area appears to get pinched down at the suction end. Is it possible to make the box wider and possibly taller, so that a 2.5" diameter equivalent flow area is maintained?
Rather than cutting a slot in the plywood, is there a way to nail or glue the sheet metal to the top edge? The slot may be unnecessary.
I like the long, swooping curves of the sheet metal, but it could be simplified as having two straight sections, with a crease in the middle. This way, the sheet metal could be bent (one crease) easily to fit the top of the plywood.
Funny, to me it still looks very boxy. That’s part of the reason for the curve.
Remember that the bottom of the sled is open where it gets lower. This adds another 1" to the height in that area, so it has less of an effect on flow. According to my math, it’s about 125 CFM in that area. I have about 20 mm of width that I can add, which would increase the flow to a max of 184 CFM.
So the answer to your question is yes, I can increase the width.
I don’t trust nailing into edge grain of plywood or gluing steel to plywood, I think the slot will be more reliable.
What do you have against curves? 
It’s possible, but personally I think that having the curved sections doesn’t increase the complexity enough to offset the added clearance that it offers.
not to mention the airflow will be better with a curve than with angles
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So I’m prepping the dust chute for printing and this is a demanding print. My slicer estimates 15 hr, 50 min print time, and 94 meters of filament. O.o That’s pretty much all of what I have left for black filament! After running it through my slicer, it should cost me about $40 $14 dollars to print the part, and that’s entirely the energy and filament mostly filament.
Before I even start talking about selling part kits, I want to have a proven design. I still haven’t gotten my Maslow running again, and it will probably be a least a few weeks before I will need to use it for the house remodel.
I’m considering the design of the 3D printed dust chute frozen at this point, as I’m committing a lot of time and material to it. I’m pretty confident in my math, although I would like to quantitatively test each of the chutes being developed for their real-world CFM flow rates.
Here’s hoping the print goes well. I don’t have a lot of room for print issues! This will be one of my largest 3D prints to date.
EDIT: I was very, very bad at doing math in my first post. I ran my time cost on the minute instead of the hour. Energy usage is, in fact, measured in kilowatt/hour. Sorry about that, I really should have sanity-checked my numbers before posting that. I’ve fixed the values about to reflect the actual costing, which is much, much more realistic.
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Good luck!!!
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One thought. Just to manage risk, you might build the cheap stuff first. If you build the wooden part of the frame first, and you need to change something. That change might affect the design of your $50 3D printed part. If you build the cheap stuff first, you reduce the risk of having to re-do the $50 part.
Josh
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Yes this was my thought also.
A valid point and something I wasn’t thinking about yesterday. If I had seen that before I started the print, I would have held off. Admittedly, I’m anxious to get this going and I have more access to my printer than I do my Maslow. I guess at this point, if I run into an issue with the parts interacting, the wooden frame is going to have to change around the dust chute.
The good news is that the print was (mostly) a success! It should be good enough to work, even if it’s not the best print. It took 14 hr, 45min. It finished somewhere around 6:30 this morning. The cats do not like when the printer is running overnight, though.
“Finished” Part on the Printbed:
Where it was when I went to bed last night:
Layer Separation at the hose connection:
I had some issues with warp-age, the support structures, and layer separation. It’s nothing I can’t fix with some acetone welding and caulking, but it does speak to the quality my current printer offers. Even though it has a large print bed, I really think it’s limited to being able to print smaller parts. I have very limited print options, and the heated bed is pretty cold around the edges. If I were to sell these, and that’s a big IF given the cost of making one, I would want to wait until I got my Prusa built. I would have a lot more control over the print and the MK42 print bed is a clever bit of engineering.
Moral of the story, I should prioritize building the new printer. xD
@Bee and @Mooselake, I know you are accomplished 3D printer guys. What would be the best way to fix this layer separation? Assuming I had enough control of the slicer, what settings would you use?
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What material is this? Are you printing in an enclosure? What is your layer height?
Thank you
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It’s ABS, though it’s not the greatest quality filament, so that might be part of the issue. The printer uses proprietary cartridges, so I can’t use better filament. I was able to flash the eeprom chips in the cartridges for a little while and I got better results with other filament, but the firmware got updated at some point and it was able to recognize the flashed the chips. I haven’t figured out how to revert the firmware yet.
This is the printer back when I was easily able to flash the cartridges:
The printer is it’s own enclosure, although it doesn’t regulate the temperature inside the enclosure.
My layer height is 0.3 mm. I could reduce that to 0.2 or 0.1 at the expense of print time and filament.
OK - ABS wants heat 80-100c to not warp. You could try a heat gun. You will get better results with PLA. I know the XYZ - you might be one of the few still using one. They tend to end up in the dumpster. It might be a decent printer with a Ramps controller. But I don’t think the heat bed on it is good. You could retro fit a new heat bed.
The YXZ was a good way to get into printing but limited in how far you can grow.
A good all around printer is the Luzbot. The next least expensive is a Prusa I3 Clone. There is little else in between. The Prusa I3 Mk3 is a great printer but the cost of shipping and the wait time make the Luzbot a clear choice.
The mini delta from MonoPrice is nice as is there line of non delta printers are good too. I feel the mini delta is too small for the parts you are making.
Happy printing
Thank you
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Thanks for the pointers, @Bee!
The read-out says the bed gets to 90* C, although I would believe it if that was only in the center. I tend to get warp-age if I have a part big enough to get to the edge of the bed. Believe it or not, but I do a lot of larger prints for models or hobby stuff like this.
Believe it or not, but I’ve never printed with PLA. I could give it a try to see how much better it prints. I get the sense the XYZ optimized the printer for PLA, even if it has the heated bed and enclosure.
Your comment about me being the only one still using an XYZ gave me a good laugh. I could definitely see that, given it’s performance. I have been thinking about scavenging the steppers and linear guides for the Prusa clone, seems like a better fate for my first printer.
Funny, I never thought about retrofitting the printer with a Ramps board. I will be buying one to build my Prusa clone. I guess it makes sense, it’s all hardware. I have a MK42 print bed that’s slotted to be used with the Prusa clone. It would also improve the XYZ to have the better bed.
I did inherit the printer. The previous owner wanted to play with 3D printing and hardly used it. I got it with maybe 10 hours on it, and I’ve since put over 500 hours print time on it in the two years I’ve had it. I really shouldn’t complain, given that I got it for free.
I’ll do some more research into the other printers you recommended. I’ve heard good things about the Luzbot. I’ve already bought/printed a lot of parts for the Prusa clone, so that will probably be the route I go though.
EDIT: I did the math very, very wrong on the chute costs. I calculated my energy use based on the minute, not the hour! I should have sanity checked that number first! It really only costs $14 dollars to print.
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That sounds a lot more reasonable. At the previously stated price I would have encouraged you to look into injection molding or vacuum forming.
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Make sure you get a good dedicated power supply for that I3 clone. Under powered ones will have you pulling your hair out. It’s about how much they can produce per output. Not just Watts and Volts. The joy of learning the hard way …
Thank you
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At fifteen hours per print I would still look into vacuum forming anyway. Watched a video on building a DIY one earlier today by I Like To Make Stuff. I get paid way over 1$ per hour for my time🤑
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