Dust Management System

I looked over the prior posts about attempts to develop a dust shoe for the MechMate and I developed a list of requirements for myself and by suggestions made by others:

• The ability to easily move the shoe out of place to be able to set Z on the work surface and to perform bit changes.
• The ability to have the dust shoe move up and down with the Z slide.
• The ability to have the dust shoe ride a fixed distance above the material in 2.5D. This keeps the suction on the table during z movements.
• The ability to support 4" suction line.
• The ability to easily remove the entire dust management system for special projects where it isn't required.
• Ability to accommodate a spoil board resurface bit.
• Easy to make adjustments - minimal tools or tool-less where possible
• Cheap, off the shelf parts
• No major changes or redesigns of the MechMate
• As small as reasonably possible - not a huge rectangle that covers up the work

I think I've scrounged enough ideas and made a few improvements to meet the goals listed above. After 21 tries, I have come up with the following MechMate dust management system. I'd like to solicit ideas for improvement or flaws. Once I've received enough feedback, I'll finalized the design and post the parts list and drawings.

Upgrades I already have planned:

• Dust shoe in 3/4" Plexiglas so you can see obstructions and the work under the shoe
• Switch from plastic skirt to horse hair

YouTube video of the Dust Management System in operation:
http://www.youtube.com/v/XOzDRlpfLWQ

Photos:
First - samples of a few of the prototype versions
Second - the major parts of the dust shoe
Third - closeup of the hinged section of the shoe. note the carriage bolt to reduce the obstructions.

Originally Posted by Art

Simple, clean and effective! Now for the hard part where do you get the guides for the rods and what are they called?

NOTE: This is just a preliminary BOM for the Dust Shoe and is subject to change:

2440K025 4 Each Fully Threaded 4140 Steel Rod End, 1/2"-13 Thread Size, 1-1/32" Head Dia, 3-1/2" L

9414T11 1 Each Black-oxide Steel Set Screw Shaft Collar, 1/2" Bore, 1" Outside Diameter, 7/16" Width (you can get two if you want both sides to lock)

3503K24 1 Each Polyamide Knurled-rim Ball Knob, With Steel Stud, 1/4"-20, 1.18" Thread Length (you can get two if you want both sides to lock)

90975A033 1 Pack Steel Tee Nut, Plain,1/2"-13 Internal Thrd, 3/8"h Barrel, 4 Prong

91236A972 2 Packs Znc-pltd Stl Low-strength Hex Head Cap Screw, 1/2"-13 Thread, 18" Length

This was my order with McMaster-Carr for parts that I didn't have in my workshop. You will also need:

• 1/2-13 Carriage bolt 2 1/4 or 2 1/2" - Quan 1
• 1/2-13 Lock nut - Quan 1
• 1/2-13 Standard Nut - Quan 6
• 1/2-13 Jam Nut (or a standard nut cut in half) - Quan 4
• 1/2 Washers - Quan 8
• ~7/16" Coupler Nut - Quan 1
• ~7/16" Bolt 1 1/2" Long - Quan 1
• ~7/16" Washer - Quan 1
• 1 1/2" .250" ID Spring - Quan 1 (you can get two if you want both sides to lock)
• 4" DWV PVC pipe with ~4.2" OD
• 3/4" MDF - 12" x 12"
• Skirting material (still under design - though I am trying to make 8801T26 Galvanized Steel-backed Conveyor Strip Brush, Horsehair Bristles,3/16"w X 7/32"h Back,2"h X 3’l work)

You of course need hose clamps, hose, a dust collection system, etc. I recommend Harbor Freight's "2 hp" unit, part #45378 (I purchased mine on-line for $169.99).

The "rods" are just extra long 1/2" bolts. You need to drill out the eye-bolts from .500" to about ~.520" to make sure they don't bind.

Thanks,
David

I've made an improvement on the prior posted design. I've cut a support bracket for the top of the support posts as shown in this photo. I think now I'd recommend anyone building one to purchase two of the locking collars instead of just one (and the spring/knob that goes with it). I got some time today to make some cuts with it and I'm happy to say it works quite well - hardly a speck of dust escapes.

I though I would pass this along. I purchased the Harbor Freight 2HP dust collector (part 45378-9VGA) for $169.99

http://www.harborfreight.com/cpi/cta...emnumber=45378



The harbor freight unit comes with 30 micron filter bags (think heavy t-shirt material). You can convert it into a 2.5 micron unit with the simple addition of the bags from this Grizzly unit:

http://www.grizzly.com/products/2-HP...ron-Bag/G1029Z



The parts you need are:

• 1 - Part Number G5556 - $24.95
• 1 - Part Number H6899 - $5.95 (actually you can just use any proper diameter PE plastic bag and save a few bucks)

They are direct fits for the Harbor Freight unit. The 2.5 micron bags are much heavier and are more like heavy felt. When you are done, you basically have a $259 Gizzy dust collector:

http://www.grizzly.com/products/2-HP...ron-Bag/G1029Z

Worked great for my dust collector.

Due to cost and complexity, I think I'd recommend against purchasing the McMaster parts:

9414T11 - Collars
91236A972 - 1/2"-13 Bolts
3503K24 - Knobs

Instead I would purchase standard, off the shelf 1/2" -13 threaded rod and two of these:

http://www.grizzly.com/products/G7318



This method has the following advantages over the collar/knob arrangement:

• These have a simple push button to raise and lower the shoe - less moving parts (knob and spring)
• Less likely to come loose with vibration
• Allows the use of cheaper threaded rod
• Allows the upper support to be bolted for better support
• Allows easy expansion for extended Z units

I'm going to purchase some and report back later.

I would now recommend two, 3ft lengths of 1/2"-13 threaded rod along with two of these threaded shaft collars:

http://www.grizzly.com/products/G7318 ($7.95 USD) - Quanity 2

These threaded shaft collars are really nice and are, in total (shaft, spring, knob, long bolt), cheaper than the extra long bolt "system". The threaded rod also allows you to put one or two tube supports along the length above the Y-Car (shown in photos below) and double nut each side to keep them in place.

I also would NOT recommend opening the .5" ID hole on the McMaster rod ends (part 2440K025). The threaded rod is already a bit under the .5 and floats with enough play without opening the holes.

If you are a profectionist, you might want to turn down the base of the threaded rod collars to make them sit directly on top of the rod ends since they are larger than the orginal non-threaded collars. They also would turn (for fine adjustments - see below) better.

On a side note - as I mentioned below, I would recommend two collars even though you could make it work with one. The reason is that you can leave one collar at a particular height, say 3/4" from the face of the material to the bottom of the shoe. You then leave this "present" one in the same spot and don't touch it (it's like a radio preset). Then when you load sheets or have to raise the dust shoe out of the way (if you don't have it bolted to the Z slide), just lower the non-preset collar down below the preset collar, load the sheet and then just raise the non-preset collar and the preset collar will then be right at the height you need for that material.

Another side benefit of using the threaded rod is that with these threaded collars, you can just twist the collar for "fine" adjustment. The other method I orginally came up with was hard to make "fine" adjustments - this one works perfectly!

Hope this helps. I will put the final parts list in my master BOM. I will also release the drawings once I've made a few more corrections (issues with large cutters and finger safety.)

Thanks,
david

I've included a seperate setion for the Dust Management System (and dust shoe) in my MechMate BOM located here:

http://www.mechmate.com/forums/showt...27&postcount=1

Link to the current MechMate BOM in Microsoft Excel (2003 format):
http://www.dmoore.com/MechMate/bom.xls

Link to the current MechMate BOM in HTML format:
http://www.dmoore.com/MechMate/bom.mht
I am cutting what I hope is the final version of the dust shoe this weekend and hope to have the final drawings posted soon.

THIS IS SUBJECT TO CHANGE!

Here is the next to final version:

http://www.dmoore.com/mechmate/DustShoeVer3.crv

Photo of posted file: dustshoe (Custom).jpg

The above file is a v-carve pro file, you can open it with their trial version at http://www.vectric.com/WebSite/Vectr...s/download.htm. The above file has all the tool paths in it.

I would highly recommend cutting it from MDF or some other scrap wood first and work out any bugs. The spacing of the router hole was based on my setup and may require changes to work with your system.

I welcome any feedback on improvements or problems.

Thanks,
david

Here are some nearly final photos of the dust management system. I've cut this show out of .7" clear PlexiGlass. The horse hair brush is expoxied to the plastic. All in all it works well. All the parts for this setup are in my master BOM. If someone has a better idea for affixing the brush to the PlexiGlass, I'd love to know it.

On to the photos:



From the bottom looking up:


From the side:


A photo of the fully adjustable, two level height adjustment: