Hardware-Free Furniture

First, I want to thank the folks at V1 Engineering for these awesome machine designs…it’s been a fun few months setting them up, familiarizing myself with their operation, and ultimately jumping into the world of CNC at home in my garage. THANK YOU!

I’ve decided to post about something I’ve been working on during the last week or two as the country has been locked-down for Covid-19. I hope you all remain in good health during this strange time… sincerely. Anyway, after looking at some Opendesk and AtFAB furniture designs, studying a few different cnc joinery techniques, getting familiar with OnShape, and Estlcam, and deciding to stick solely with sheet plywood as my building material, I designed a simple end table that can be cut and assembled with a small amount of glue at the joints in about 1.5 hours from first cut to fully assembled. These design cues will form the basis of several different pieces I’d like to design, so this is just the first of hopefully many. All the designs will be free and searchable in the OnShape public repository, and I’ll post links as I add new designs. While this first design and layout wasn’t optimized to conserve sheet ply material, my goal for the future would be to optimize the use of the negative space between pieces on the sheet ply to place other parts for the various furniture pieces I hope to design in order to minimize the scrap heap…that takes time and more designs, so not ready for that just yet.

Long term project goals would be to use variables in OnShape for dimensioning all the joinery so things auto scale as needed, and I can just focus on making nice designs without tedious joinery solving. If anyone knows how to do that, I’m all ears :). I’m an electrical engineer by trade, so I can figure out some complex math, but all this physical structure stuff is a new world for me…I really enjoy it so far. Also, I intend to stick with OnShape for all the design work so that I can easily visualize the designs and grow into 3D pretty readily as I get more familiar with that design platform and my LowRider CNC’s operation.

OnShape Link: Hardware-Free End Table![First Furniture Piece|667x500]

Final cut picture: Final Cuts on Ply

Test assembled but not sanded and glued yet picture: Assembled

All in one picture: https://photos.app.goo.gl/QipGCJxPvkMMCk5R6

Video of LowRider in Action: LowRider Cutting End Table

If you want to make this yourself, you can either export the drawing from OnShape (It’s at 1:5 scale), then import to Estlcam and scale up by 500%, or you can use the STL file in OnShape directly as a 3D export (not required as there are no 3D contours on this one).

Info for making:

Bit specs: 1/4 inch straight cut bit
Sheet Ply Specs: 3/4 inch (~18.6 mm as measured) birch plywood from Home Depot
Estlcam Settings:

  1. Scale drawing by 500% if using the drawing file
  2. All through cuts at least 19mm (+/- 1mm depending on how good your Z accuracy is)

The video above was actually taken just before my machine caught a snag on the vacuum hose due to a zip tied stepper motor wire (tried to be tidy) that I’ve since removed (zip tie I mean)…anyway, I had to do a slight re-design to the bottom leg support joint, so that cut piece was never used. When I finish sanding and staining, I’ll post the finished pics too.

Enjoy!
Jim

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This is very cool I will. Be trying some of there designs I love cnc cut furniture

Thanks Tim! I was actually going to try and fab an Opendesk design, but their downloadable files aren’t available at the moment, so I decided to take a crack at designing my own. Glad you like it.

Liked it very much

Very nice. I also enjoyed the view of your shop…with each of your robot minions in their own cages. :rofl:

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Nice work!

Haha! Yes, that way if they misbehave, I can put them in timeout :). I built the enclosure for my 3D printer first, then I decided to put the MPCNC in it’s own enclosure too, and it keeps the dust and noise down considerably so I don’t bother my family or my neighbors. It’s been a fun month of projects, but all of the robots are happy in their homes.

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Thanks Ryan! This machine you designed is quite awesome, and I have a lot of jealous neighbors now…you might get some more orders from Denver very soon :).

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Awesome work!

  1. Why the 1:5 scale and then scaling up by 500%?

  2. Are there any components that are relative to a 1/4" bit? Would a 1/8" bit work just as well?

  3. You can set parameters in onshape, and use them in equations. You can also make some clever decisions while sketching to make the relationships between features dependent on those parametered parts. But there is always a limit to how far that will work. Making it work for a 24" or 26" table height is no big deal. But changing it to 48" might break stuff. Or going from 3/4" to 18mm pockets is fine, but going to 1/2" might break some stuff. In the end, I always find myself balancing between the desire for being generic, and the desire to finish the design… I also usually keep my polishing steps at the very end. That way, I cam rewind history to make some dimension changes, and just redo the finishes (like chamfers or round overs).

  1. The 1:5 scale was something that OnShape did automatically to fit the drawing on a single page. The properties can be set to 1:1, but then the drawing is much larger than the page, so I just left it as is in OnShape for easy viewing.

  2. Most components and / or variables are based on plywood thickness, not cutting bit width, but that’s an interesting way to look at the auto scaling functions I could create. I’ll think about that and use it in my next project.

  3. Yeah, I initially wanted to create mirrors around construction lines and attempted to auto scale everything, but I quickly found out that I had a difficult time constraining things so that I’d get what I wanted…I’m just learning OnShape, so I may be able to figure this out as I dig in to the software. I’ll keep you posted. Thanks for the feedback!

Here’s one final picture of the finished product:
Finished Piece

It’s difficult to tell in the picture, but I was trying for the “weathered” look, and I purposely knicked some edges with my sander to make it look worn in. I just used oil-based poly to finish, and the natural look came out very nice…birch is pretty nice that way. I may just use oil in the future, but we’ll see.

Going forward, I will definitely slow down my feed rate and plunge deeper into the material with each pass per Ryan’s suggestions elsewhere, and I’ll definitely do a finishing pass since I got some jitter on this one…had to sand more than I was hoping. My goal is to be able to pull the piece off the table, hit it with my orbital sander, do a quick roundover on the edges with my trim router, and start piecing it together…had to do a little more with my disk and drum sander on this one, and if I take my time cutting, maybe I can cut those steps out.

Anyway, I’d say this was a successful project and I’m ready to design the next piece. See you all soon!

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Ok…as promised, here is my next project. I decided to design a bed frame based on Craig Stover’s Trestle frame located here:

Trestle Bed Frame

Craig’s design uses no hardware, but I believe he made his with access to a full 4x8 ft. capable CNC. My Lowrider isn’t that big, so I had to find creative ways to split up the long pieces with joinery and wedges to ensure structural strength. This is a work in progress, and I have not cut this with my CNC yet, and I haven’t laid the parts out to see how many sheets of plywood I will need to get all the pieces covered. My design uses 3d printed wedges for the scarf joints on the long supports and side support rails. The goal is to eliminate glue and screws and just use my CNC and my 3d printer for all the parts. Here is the Onshape link if you want to attempt to build it yourself:

Queen Bed Frame

If you have a large enough CNC, maybe just try Craig’s design and donate to him if you’re able. If your CNC is smaller, like mine, maybe my design will work for you. Feel free to hit me up if you have questions about making, but just remember, I haven’t cut anything yet, so I’m learning right along with you :).

Cheers!
Jim

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Dumb question, how do you get from Onshape to Gcode? Do you use the plugin from Free CAM app in OnShape thread or something else?

You certainly can. In fact, @stewart is not unknown to us here, and is usually pretty receptive to commentary about Kiri:Moto…

It also does slicing if you want to do some FDP work out of OnShape as well…

I usually make a new sketch on a face I want to cut from, and “Use” features from the 3D model. Then export to DXF. I just recently started working with kiri:moto though. I haven’t pulled the trigger on a job with it yet though.

thanks @kvcummins

@anttix if you need help with Kiri:Moto, we have our own dedicated forums.

Kiri existed prior to Onshape and runs inside and outside of it. The CAM features were largely prompted by Joe Dunne at Onshape after I did the initial integration. And it remains under very active development. Bug fixes and feature improvements roll out weekly.

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Oh wow! That was a fast reply. You guys are really committed to this forum :smiley:

I only created an OnShape account a few weeks ago and haven’t used it at all. So far I have been mostly rummaging around in Fusion360.

Kiri looks very interesting. It’s a totally different concept. I would love to be able to just trust the CAM to automatically figure out what it needs to do to mill down my stock and make it look the part.

Why I asked about OnShape is that I’m getting frustrated by the amount of manual work I need to do in Fusion when designing even the simplest plywood items. I haven’t designed a lot of pieces yet so I’m always hesitating and wasting time trying to find a better way which is part of why it’s taking so long. However after working through tons of Youtube videos I’m not sure if there even is an optimal way to design basic furniture pieces in Fusion. In my little head I would expect to be able to model the shape, then cut it to panels, add joinery (tabs in case of flat-pack) and be done. But no matter how I try, I always end up doing lot of annoying gruntwork with the joints. So far the best I have been able to come up with is:

  • Manually extrude a tab and then pattern the “feature” along the edge.
  • Cut the other panel with the first panel
  • Offset pocket faces to create some clearance
  • Use dogbones add-in on every face that has pockets

Even a simple script that would allow me to say: “Hey, half-lap these two intersecting bodies”, would be a massive improvement. I know I can potentially make a few parameterized boxes and then just copy-paste these from design to design, but this is no fun plus dogbones may not survive parameter changes (more about that below).

If someone knows of a more efficient workflow, please share it :slight_smile:

Now don’t get me wrong, Fusion360 is a great piece of software and I’m happy hobbyists can use it for free but the bugs it seems to suffer from don’t really invite me to build any extensions or macros for it. Take dogbones for example, there are three add-ins that I’ve found so far: Two free, one paid and none of these work well with parameterized models. If you’re lucky you get holes that move with parameters by using one of the free versions, but more often than not you still have a few panels that error out and the “static” mode basically just suspends the holes mid-air so any resizes or body moves will throw them off. The paid variety doesn’t have a parameterized mode at all. From demos I’ve seen it comes with a separate command to “recalculate” dogbones after you’ve changed parameters. Thus nobody has got it to work well. Bugs reported by the author of one of the free dogbones add-in are still open after 4y.

So yeah, I’m looking for something that I feel comfortable to program so I don’t have to do so much manual work which probably results me wasting even more time than I would by drawing the damn tabs by hand in Fusion :smiley:

For funsies, try this in OnShape:

Create a simple box/frame/chair/whatever without joinery. Just the shapes. Can’t remember if they should be overlapping… Anyway, once you’ve got it made, look in the upper right area of the screen, on the right end of the menu, there’s a dashed box with a plus sign in it. It allows you to add features. Click on it, and add a community feature. Do a search for “Box Corner”, and add it. Then you can use it to create finger joints for your construction. It will even include the dogbones. If you want top get crazy, also add “Auto Layout”, which will take all your parts, and lay them out flat for you in a fairly reasonable manner.

Here is a Ramps case I slapped together using Box Connectors.

https://cad.onshape.com/documents/e0705bbb82e049ad823383d6/w/a5bef7ddd880f1b92b34b466/e/cebd03f7aac5aa609f81e124

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K, that is a neat looking box and a neat feature. So far, I have use estlcam for cam and I use the overcut feature at that point, instead of using any features in CAD. There have been a few times where I wished there was an “undercut” feature, where I could dull a sharp convex point by the radius of the bit quickly.

Sometimes I forget to dogbone something, and it has never taken me more than a minute to clean it up with a sharp chisel. Just something to think about.

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