Community challenge #11: multi-sided machining (closed)

Olle · July 19, 2020, 10:02pm

First post on the forum! I have been lurking around here for a few months learning many things from other users so I thought I would try to contribute and share a small part machined on the Nomad this weekend. The cover for the lamp on the stove was broken when I moved in to my apartment so I thought I would machine a part that would shield the lamp and diffuse the light. To try and achieve this I modelled a part in fusion 360 with a “pyramid pattern” on the inside of the cover using two perpendicular V-grooves and rectangular patterns. (Perhaps this could be readily machined using a V-bit instead of the hours I spent machining it with ball end mills).

I machined the part in polycarbonate and flipped the part once using 4 mm dowel pins to locate the part using the bed as Z0.

The part is pushing the smaller build envelop on the Nomad a bit so I did a dry run with the end mill 5 mm over the bed to see that I did not hit any end stops with the first toolpath. I used 2mm and 3mm flat end mills to try different speeds and feeds to clear out the majority of the material and a 2.5mm and 1mm ball end mill in succession to machine the light diffusion pattern. There were some small strands of polycarbonate still attached to the pyramid pattern after finishing with the 1 mm ball end mill, perhaps I should have done a spring pass with the same end mill to clear that out but I was too eager to see the part finished.

!

I cut out the part using tabs but should probably have used double side tape or the machined screw holes for holding the part down as the tabs left small blemished on the part that light up a bit when light is passing through the cover.

I was mindful to not machine the bottom surface of the part as I wanted it as transparent as possible. The idea was that the light diffusion pattern would diffuse the light but I think the majority of the light diffusion is done by scattering caused by the ridges left by the finishing toolpath (1mm ball end mill with 0.1 mm stepover).

Before and after picture!

Link to CutRocket (Pretty specific for my stove lamp haha… But perhaps it could be useful for someone to look at the speeds and feeds or the modelling of the “pyramid pattern”: https://cutrocket.com/p/5f14c01312573/

PhilG · July 20, 2020, 12:55am

Brilliant. I am going borrow that idea for my stove hood!

And welcome aboard another Nomad owner!

Julien · July 20, 2020, 6:22am

Team Nomad is on fire !
It’s interesting to see such diverse entries, yet another testimony to the versatility of our machines.
(and welcome @Olle! no better way to make a first post)

Olle · July 20, 2020, 8:28am

Thanks for the welcoming guys! I’d love to see that part if you end up machining something similar @PhilG!

enl_public · July 21, 2020, 5:26pm

Why not throw another one in, since at the moment I don’t think I’ll have the time to do something artsy. Another part for a comparator. This time a riser with a fine vee-groove for inspecting and measuring small round things (tools for the Nomad, among other things, but actually made so I can inspect pars I am working on for actual work)

This is based on the same base model I posted the other week. All I changed in the model was the height (parameter value) and the groove profile.

The model:

This was machined in two setups. The first was from raw stock. Here, the stock was pocketed into the wasteboard,

using the same socket as the last time (put in by the scheme bore, measure, rebore and test fit, repeat until proper snug fit). Again, I didn’t bother cleaning up the stock much. The ends were square enough to finish-- flat within 1.5mm stock allowance either end.

Machined the bottom side, bored holes for 3mm dowels,

and surfaced new location for the second side mounting and bored fresh dowel holes to insure perfect zero (drill at 0.9mm, then bore using 2.4mm flat mill)

then pop in the part for setup 2 with double-sided tape to keep it down:

For both, the zero is center and at the mating surface with the wasteboard. The first setup had stock allowance on the bottom, as it was rough, so the zero was on a stock point. The second, being a finished surface, the zero was on the model. The machining on the first setup did the perimiter a bit over half way down. The second setup did the same.

Then the vee groove using a 45 degree chamfer bit

perimeter with a ball end, and a narrower vee bit (60 degree vee carving) to clearance groove the center of the vee slightly. The bit has a slight flare at the tip to make the 0.1mm flat, and in this case, it the ideal tool for a narrow clearance groove, much better than the smallest ball end I have on hand.

The product:

The top is dead flat though there is shadowing of the tool path. There is flat patterning due to the interpolation, but the size of the flats relative to the size of the part (100mm-ish) looks large, but the max error is less than 0.02mm on the round surfaces.

Setup on the machine with a tool for inspection (a 135deg split point drill. Done several hundred holes in T-11 chrome-moly material, looking at condition. Tough to photograph, as the HDPE is SO bright when the illumination is on):

The models and setup sheets (inventor) for those interested:

riser2-with-cam.zip (2.3 MB)
riser2-with-cam-setups.zip (2.1 MB)

ColdCoffee · July 22, 2020, 6:55pm

This is my favorite project I worked on with my kid. We made iPhone cases on our Nomad 883, and our own two sided jig to help us get repeatable results.

So let’s start by looking at 8x8 Nomad 883 waste board we modified. The left side of the waste board was pocketed to perfectly hold 3" by 5.5" blocks of wood (two sided tape in the middle for insurance).

We could then CNC one side of the iPhone case.

Once one side had been cut, we could flip it over onto the right side of our waste board. The slots on the right side of the waste board held the iPhone case in place so we could CNC artwork onto the back side of the case.

We then got into different inlay materials, and could customize cases with unique designs. The “Cold Coffee” case was my kid’s, we inlaid a circuit board that was pulled from a dead inkjet printer. And then added a copper inlay as it was somewhat like the color of coffee.

I think that case got even better looking as it aged. This is what a teenager does pulling a phone out their pocket a million times a day.

The very first photo of the “Visual PLB” case (that I took today) is my current iPhone case. I have used this case for over 2 years. I’ll admit I cleaned it up for this photo, but the brass and bamboo have held up WAY beyond my expectations. Bamboo is by far my favorite material to CNC.

iPhone5.mcf (20.0 KB)

iPhone5 PLB.zip (1.6 MB)

Julien · July 22, 2020, 7:09pm

Oh boy, now I have to try “PCB inlays”, that looks fantastic
The “side by side flip jig” is very nice too

Liquidice · July 24, 2020, 3:56am

Some love for the Shapeoko

Watch a video of my 3 setup/ 4 bit change toolpaths here:

F360 design here:
https://a360.co/31al5O2

Julien · July 24, 2020, 5:14am

Nice ! Now you have to tell us what this is for? watercooling system ?

ccm · July 24, 2020, 5:25am

Looks like a hotend for a 3D printer.

Liquidice · July 24, 2020, 5:26am

It’s an all in one x-carriage, hot end and direct drive extruder mount for CR10s and Enders. This will replace a bevy of heavy sheet metal and an underperforming stock hot end.

dakyleman · July 24, 2020, 12:16pm

@Liquidice Awesome work! Love the cooling fins and standoffs for the fan! Any heat transfer calculations on the fins? (I mean, it looks plenty capable I’m just curious).

I might have to do something fun like this for my Wanhao i3…looks like you have the Z-Plus for your Z-axis? Looks more than capable in aluminum!

Nice work again!
Kyle

Liquidice · July 24, 2020, 1:42pm

I ran a FEA analysis in fusion 360 with a nozzle temp of 220C; outcome put fins in ~35C range with cold end of the heatbreak zone at around 45C.

moakley8 · July 24, 2020, 5:10pm

Working for Autodesk i get so many people on CNC threads complaining about Fusion 360 and that Autodesk is trying to just take your money. But when i see someone like you take advantage of high end FEA capability to solve a problem, I get happy. There is so much value in Fusion360 beyond Modeling and CAM for such a small price. Nice work.

Liquidice · July 24, 2020, 5:29pm

10/10. Fusion360 is an incredibly powerful tool, and when it’s time for me to move from a free plan, I will purchase a license with zero complaints.

PhilG · July 24, 2020, 8:37pm

The more you do on F360 the more you learn how deep it goes. These competitions definitely push me into areas of F360 I haven’t explored before. I used FEA on my plastic flexture in the last competition to check on the stress points. Not free but those few trial runs that are included to get you hooked!

This time around it is …censored… and … censored… !

Radiation · July 24, 2020, 11:03pm

So I edited my previous post to add pictures of the 2 ghosts I just finished last night.
Also whipped this up really quick:

I pulled this file into Fusion: https://www.thingiverse.com/thing:684102
Scaled it down by 50% to fit the nomad, and then cut out stock from carbide create to include holes at the corners for flip/allignment.

Used blue tape and super glue to hold everything down since that’s my preferred method at this point.

Didn’t really sand off the machine, because of laziness:

Fusion file: https://a360.co/3k3grK2

wb9tpg · July 24, 2020, 11:18pm

Got a question on the rules? Is it legit to post a project with the proprietary STL file portion removed (vcarve)? It seems that is keeping me from entering the contests and I’ve like to participate.

Radiation · July 24, 2020, 11:43pm

It’d be something @Julien would need to weigh in on.
You could just grab something to do for funsies.

Julien · July 25, 2020, 9:37am

Hi Gary,
The point of that rule is twofold

that these challenges do not turn into “who bought the fanciest vector on Etsy and posted a picture of the awesome result”. That would sure get a lot of votes but most of the credit would go to the original Etsy artist, and that’s not the point.
that folks get a chance to look at the toolpathing strategies used for entries.

Posting a file with the vector art removed would satisfy #2, but not #1. Also I would like to avoid some head-scratching when validating the entries for things that are “on the line”.

So to meet that rule the best would be if you can derive a non-proprietary version of your project. Replace the proprietary vectors with something similarly sized that you would create (or find, that is free to distribute), and rerun the cut ?

Alternatively, I think the C3D contests over on the Facebook group are based on “pictures-only-no-questions-asked” entries (I know this was not your question, and you may or may not want to visit the FB group, I am just mentioning this in case anyone is interested)