"Alligator" ribs for dust shields along the Y-Axis


For my first useful project with the Longmill, I thought it might be a good idea to try and contain the chips and dust that it spews out the sides. Very important to contain the dust for the WAF (wife-accptance-factor) as my shop is in our garage and directly attached to the house.

In the spirit of making do with what is on hand and also recycling as much as possible like the Sienci approach, it occurred to me that the shipping box the unit came in could provide the ideal material for the side dust shields.

I cut one long side (complete with top and bottom flaps) off the main box, then I used a utility knife to cut the top flap off as I only needed one flap and the long side. Seeing how well it worked, I would be more careful cutting the top flap off in future so it was tidy.

I sat down with Sketchup and Fusion and designed a simple single piece support rib suitable for use on the right side of the machine (assuming you have your machine right aligned on the wasteboard like the standard build).

Here are some pics:

Right now I just have it sitting in there and it works pretty well. I did stick a single piece of tape on the far arm to try it out, but the preferred way to lightly affix the cardboard to the arm would be a simple thumb tack from the cardboard side through to the MDF or plywood. That way it will stay in place but can be remove trivially if you need it out of the way. The lower edge of the cardboard is already resting in the groove in the photo.

One tip if you decide to make some of these - gently predrill your mounting hole in the MDF before screwing. It will likely still split a bit even with the drill bit (you’re going sideways through MDF) but the single screw plus the 90 degree edge seem to hold it just fine. You can’t put too much weight on it or you will snap the arm but it can withstand a few accidental prods of the cardboard.

There is still a small gap along the bottom edge, but I intend to cut some lengths from another off-cut and seal that up so I can keep the dust and debris on the work surface for easier cleanup.

I cut the 'Gators out of some cabinet MDF scraps I had laying around. I used fairly aggressive settings of 3048 mm/min @ 17,000 RPM and did the cut in 3 passes. Material was 18.6mm thick and I used the Sienci 1/4" downcut bit. The Longmill knocked each one out in about 90 seconds. Boy did it spray MDF dust, but otherwise worked very well. Definitely wanted eye projection and the respirator, with the shop vac close at hand. Bit was nice and clean at the edge as well.

If anyone is interested I can share the Fusion 360 file or the Sketchup model.


Dust shoe installation

Jeff, great idea. I designed my table to be able to add a complete enclosure but dust boot does a pretty good job and I never bothered. This looks like the best of both worlds - cheap, easy to install, easy to remove and clean, and I’m guessing pretty effective.

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Great idea, Jeff.

I redesigned the dust boot so that I can run a 2.5" hose to the front of the router. It catches almost all of the dust now. I still like your inventiveness. :grinning:

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Do you have a link for that? One of my first questions after I got the machine together was to ask out loud “Why isn’t the dust connection in FRONT of the router?” so definitely interested in that!

Also, since I am going to mount my vertically, I need to do that and find a sweep to convert it to a vertical run if I can. Otherwise there will be serious tension on the lower edge, although I suppose I could use zip ties for strain relief…



Jeff: I can take pics this afternoon.

I used Vcarve to do the cam work. What are you using? Could you open vcarve files? I can likely attach the gcode files to a message here, too.

I’ll be back to you mid-afternoon.


Thanks, Grant. I’m using Fusion 360 and Sketchup. I suspect they can open something you can export. I’m not familiar with the native file format in VCarve though. A quick google suggests going via DXF is one option, but that will reduce it to 2D I think.

I had surprisingly good luck going from Sketchup in 3D direct to Fusion and doing CAM on the import for the dust shield arms. That surprised me as people said Sketchup output was usually probelmatic for CAM due to it not being vector based. It had the line effect on the circles but the cut was nice and smooth so I guess it managed ok…



Jeff: I cannot attach dxf files, as this forum does not accept that file format. It says that it will accept svg, but I tried to attach an svg file in another thread, and it failed, too. If you want the dxf and/or svg, just send me a PM and we can likely make that happen.
In the meantime, here are pics of my set up.
Captions as follows:

001 shows the overall setup. There is a bungee strung from the ceiling holding up the 2.5" hose. The flex hose goes to a 4" solid PVC pipe to which I can connect another flex from my dust collector.

002 shows the top of the bottom/brush part of the shoe. The three magnets hold it very firmly. You can see that I was still playing with the design after I cut this out on the Mill, as judged by the rough cut out. I’ve since modified the vcarve file to match this design.

003 shows the shoe and the hose connection. I just used the Sienci brackets to connect it to the LongMill.

004 is a bad pic of the underside of the top part of the shoe. You can barely see that the back part of the brush is attached to the top of the shoe. When the bottom is slid into place on the magnets, the brush on the top meets the part on the bottom and completes the “circle” around the router.

005 shows the underside of the bottom part of the shoe. The cut out for the router doesn’t look as bad here as in pic 002.

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This is great. I need to give my situation some more thought but I’m thinking you have pretty much what I was looking for right here. Thank you for sharing it.


I’ve sent the files to Jeff and Michael by email.


@gwilki, Gentleman and scholar.


Chris kindly (and very quickly) added dxf and svg files to the list of acceptable attachments, so here are those files for my dust show.
new_shoe_topandbottom_2.dxf (15.4 KB)


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Ok Grant, I figured out what was going on. When you were uploading the SVG the forum is displaying that as an image rather than a downloadable link, however you weren’t able to see the image either since for some reason it was being displayed as 20x14 pixels!!

So what I did (I fixed up your original post) is that I created a link by using the uploaded image as a reference, similar to what was outlined on the Glowforge forum here: https://community.glowforge.com/t/easy-way-to-link-svgs-in-forum-posts/46740

The short of it is this: after uploading the SVG originally and submitting your reply, you’ll want to:

  1. Right-click on the image and click “Copy image location” in order to get the link to the image, then
  2. Paste that link as well as the image name into the HTML code that I made below which then turns it into a more ‘download’ looking link

<a class="attachment" href="/uploads/default/original/SVG_LINK_HERE.svg" target="_blank">SVG_NAME_HERE.svg</a>"

  1. Edit your post and add that code blurb into it so that it now links to the image link

From that point, if a user is wanting to download the SVG, all they should need to do is: Right-click -> “Save Page As…” and then they should be able to save it as an SVG

Alternatively if you just want to post the SVG as-is, then any user can follow the same “Save Page As…” procedure for your posted SVG. To make sure the picture is being displayed at a readable size, just edit the pixel size in your upload: ![new_shoe_topandbottom_2|PIXEL_WIDTHxPIXEL_HEIGHT](upload://oKmXktoikwnDIhwuUKsqt0yBGkh.svg)

Whew, wasn’t expecting this level of troubleshooting for SVG uploading


Grant, these guys seem to have really thought through the dust boot situation and made a number of innovative design decisions. At first I thought $120 was nuts for it but the more I read through the details and looked at the execution the more I started thinking it makes sense to reward this kind of innovation and investment in niche products. It’s how a rising tide lifts all the boats. Check this out: https://www.reality3dp.com/vacuum-dust-collection/shapeoko-3-dust-boot-makita-rt070

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I’ve seen Keith has this dust boot, I think he was quite satisfied with it. You didn’t hear this from me, but we’re in the process of testing a new boot design which is sturdier than the previous version, easier to adjust, takes up less X-axis travel, and has a viewing window (although no LED lighting :stuck_out_tongue: ).

I know lots of people gravitate towards the dust boots that mount to the router body because they’re usually much simpler in design, but I’ve always been more partial towards the Z-axis independent boots myself. Seeing as the material you’re cutting is usually flat, Z-axis independence allows you to have a much wider range of motion i.e. deeper plunges with the router while the dust boot maintains a good ‘seal’ with the surface of the material.


@jwoody18 @chrismakesstuff Thanks for the link, Jeff. I’m still playing with designs and have not settled on one, yet. I have the hose out front and that seems to work very well. As Chris mentioned, the one you linked to attaches to the router, so it goes up and down with it. Many do.

On one of the Sienci pages, Chris goes into the pros and cons of Z dependent and independent designs, and he leans to independent. For my kind of cutting, I think that’s the way to go for me. I tend to do things that require bit changes and the bit length varies quite a bit. So, I go from a short V bit to a somewhat longer 1/8" mill to a longer yet 1/4" mill. With the shoe attached to the router, I would need to change the height of the shoe for each bit. Either that or set it for the longest bit and live with the brush being off the surface for the shorter bits.With my current design/Sienci’s design, I can set the height once and leave it.

I already have the brush completely removable and held in place with magnets, so I don’t have a visibility problem while changing bits. (The top part of my shoe uses the Sienci brackets to keep it in place, but the only part of the brush attached to it is the back piece.) I could always remove the front piece of brush, I suppose, to be able to watch what is going on. The trade off would be reduced dust collection, but it may be worth it.

My biggest beef with my current design stems from my lack of concentration. :blush: My order of things tends to be to raise the router in Z quite high, slide the shoe bracket up high, and install the bit. Then I jog to roughly XY0. More and more, I use centre of the piece as XY0, so I jog to that point. Then, I put the touch plate in place to find Z0. Then I start to jog the router down close to the plate, forgetting that I have not lowered the top plate of the shoe, which prevents the router from lowering. Duh!

So, my next iteration - still in the drawing phase - has the top plate still held in place with Sienci-like brackets. But, the opening in the top plate allows the square router bracket to pass through it. I don’t believe that I will lose much dust collection ability, as the lower plate, held on by magnets will still only have an opening just clearing the body of the router.

So far, I’ve been using 1/2" MDF for my playing. However, I’m not sure that it will be strong enough to take the stress from the DC hose if I cut away for the router bracket, without going to a ridiculous width.

The easy solution to my problem, of course, would simply be to pay attention to what I’m doing, which has been my solution so far. I’ve only met with occasional success, however.

Long reply to your short post.


Grant, totally understand where you are coming from. I’ve got the exact same “forgot a step” issue happening.

It’s annoying to raise it out of the way to change the bit, although I should really be raising the router itself and leaving the dust shoe down… Except that if I leave it down, then the zeroing block isn’t usable as the brushes bush it around. Zeroing with the boot on is a pain. I need to get to a modified version like the one you shared and add magnets. The bottom definitely needs to be removable to make things faster.

I would really like to be able to see the cut, as well. The shoe is so large there is quite a large work area obscured by it. I am very intrigued by the design I shared having the narrow end of the ractangle brushless so you can still see the bit and also easily change it without adjusting anything.

I’m running a fairly beefy Ridgid shop vac on a 2 1/4" (or whatever the darn size is referred to as). I was originally concerned with any gap in the brushes affecting suction but I have to say it really pulls and hasn’t been an issue so I’m not quite as concerned with always being right on the material, if I went the route of the 3D printed example.

What I can say is that after putting the machine together and regularly saying to myself “Wow, I really like the way the Sienci guys did this, this is so smart”, I did NOT have the same experience with the dust shoe. I think the dust shoe, in it’s current iteration, definitely feels a lot more like an after thought and isn’t up to the same standard (yet - Chris did say above that they are redesigning it).

If I was in Chris’ shoes, I might be tempted to reach out to the company that designed the one linked above and talk about licensing or doing a Longmill enhanced version. Clearly they have spent A LOT of time thinking about dust shoes. :slight_smile:



I totally get the theory there, but it does make me ask aloud whether there is a material loss in suction, or at what point it occurs, with the boot that moves with the router. What I’d offer as customer feedback is that while I originally bought the dust shoe (and got around to installing it) because I wanted to control the mess and reduce the dust - it didn’t take long for me to realize that a balance of dust collection, convenience for setup, zeroing (with block), bit change speed and visibility of the active cutting area was probably a better target. Of course what weights each item gets will vary widely by operator, but I think all items will appear on the list for most of us.



@jwoody18 Never one to leave well enough alone, Jeff, I’ve been working on a new one this afternoon. I just did one quick cut with it in place and it worked very well. I’m going to make it a bit pretty tomorrow, then try it again. If it works, I’ll let you know.


Chris, looking forward to the increased X travel and ease of adjustment. I like that window idea!Please stick with the Z-independent version - They’re way more effective.


I suppose I should make sure I give the current boot a 10/10 for collecting dust. It picks up probably 97% of what comes out and isn’t hard packed in to the cut line. I was astounded how clean it was the first time I used it.