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Jeremy Nelson
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Riley is off to Bathurst and, as you can see he is pretty emotional. Two nights, the days, back on Friday. Best wishes and good luck to the teachers!
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06/04/2016
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Its not much, but this is the ball screw mount for the Y Axis from design to completed milling. Onshape for CAD, MeshCam for CAM, a 10mm 2 flute endmill, a flymill for surfacing, 3.2mm drill bit for the holes, M4 threaded holes and a little bit of manual filing. Fits beautifully.

The chamfered edges in the design added a lot of milling time and noise- I should have manually filed them rather than considered milling them at all. It also took me a little while to work out the best way to place the zero offsets in Meshcam since I was using them for multiple purposes.  I got a few other bits wrong, but overall it worked just fine.
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2015-06-16
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We went to Vivid Sydney on Sunday night. Crazy crazy crowds. George St was closed off- and busy- Darling Harbour and Circular Quay were packed. Some fairly spectacular displays the best of which was the Museum of Contemporary Art.

And here is the family selfie...
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I did a 3D print yesterday which included M20 thread and I was blown away by how well it turned out. The part screws into a pump and adapts to 19mm flange for reticulation pipe- I'm going to use it for flood coolant on my mill.

(The model has been updated with some filleting and I made the wall thickness of the threaded section slightly to thin by accident so the layers separated when I screwed it in really hard, so I'm going to re-print the part- which should take about 30 minutes.)

The part was printed on Fine, the thread is 20mm outer diameter, the flange is 21mm outer diameter. I printed it as part of a larger print so I don't have timings off the top of my head.

Anyway- thread, you can totally 3D print it.
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2015-06-04
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I've had a very long term project to CNC my mill. Phase 1 was manually milling servo mounts using the existing leadscrews. Phase 2 is replacing the leadscrews with ball screws, this time with CNC'd mounting plates. I'm also aiming to have flood coolant, which means I need a way to evacuate the coolant from the bed. That adds to the complexity of the mounting plates.

Separately I've also been looking for a Linux compatible CAD+CAM combination. I've been using CamBam under Linux, but its a bit limited in terms of CAD. And many of the major CAD options are not available under Linux.

Onshape to the rescue: "Onshape is the first and only full-cloud 3D CAD system that lets everyone on a design team simultaneously work together using a web browser, phone or tablet." Its a constraint based CAD system, rather than the explicit modeling I'm used to, so its taken a while for me to get used to it. But I'm a convert now- I like constraint based modeling. I really like the web based application- I do most of the modeling at home, but I tweak it at work. I look at it every now and then on my laptop in bed. It just works.

And the real sign for me that its good is that I've caught problems with my designs during the CAD phase. One of the plates was 100mm wide, it was meant to be 120mm. I measured the bed length and ball screw wrong. I have gutter returns for the coolant which I was intending to mill but I've come to realize that I'd be better off 3D printing it. This is a sign that the CAD system is doing a good job- I'm catching mistakes before I cut metal or print plastic. Some shots of the assembled CAD imagery are attached.

I've also been trialing MeshCAM which looks like it will do a slightly better job of integrating with Onshape. MeshCAM also runs on wine in Linux.

All in all, very satisfying. Soon- cutting chips.
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2015-05-28
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The world's cutest 4th axis! The head is 64mm. ENORMOUS!

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I made a drag knife for my mill. Drag knives can be used to cut paper, carboard, vinyl- anything you'd cut out with a paper knife by hand. But this is CNC and capable of more intricate and precise cutting... The knife just needs to swivel smoothly in the head, and the cutting point needs to lag by a distance so it can be turned by moving the head in an arc.

It has a couple of 11mm bearings press fit into a 20mm diameter cylinder of alumnium. The knife is a milled down Aluminium pen knife. Its a nice simple design- see my one pager that design. However, I did a truly awful job.

Because of the lathing technique (or should that be 'technique') I was using the centering of the holes in the Aluminium block is terrible- so the pen knife is actually tilted. The bearings are not quite parallel so knife hitches as it rotates. The knife is was not lathed to the precise 5mm diameter shaft I intended- I was holding the lathe tool in a vice and the tool slipped, so instead it ramps from 6mm down to 3.5mm, so one end wobbles.

Its so awful I can't actually quite bring myself to try it. It'll probably work, at least roughly. I'll try remaking it at a later date since its a fairly quick process. But it was a learning experience and while the implementation was awful, the design was actually quite nice and spare. My original idea was complicated- the final design very simple. So, silver linings of a sort!
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2015-03-30
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Dishwasher magnets. We have Fisher and Paykel Dishdrawers, which work very well for us, but it does mean there are a combination of possible states the draws can be in. We have been using magnets that Kris and I 'knew' what they meant. These are... more explicit.

Colour laser printer, laminated and glued to some flexible flat fridge magnets we had kicking around with shoe goo glue to keep them flexible. So far they seem to work pretty well and I quite like how they look.
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2015-02-13
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One of the weekends efforts: a sign for my workshop-in-a-bathroom. This was produced from an image developed in Inkscape, rendered in CamBam using an image map that maps whiter pixels higher and darker pixels lower and then milled with a 3mm bit... for about 6 hours.

This was a test cut, which is just as well. The result looks amazing in the flesh, the letters in 'Workshop' are very fine (about 1mm thick) and about 10mm raised from the background. But late in the milling process portions of the wood gave way (see the middle of the W, the base of the R and several other letters). And Connor, who had been quite interested and asked lots of questions earlier in the day, came to investigate progress and carefully turned the light off as he left.

Which was actually the power point running everything.

So the cut didn't finish and it wasn't really worth trying to pick it up again. But it certainly proved that this could work. I intend to mill the sign in Aluminium, so collapsing shouldn't be a problem, although since the aluminium is larger its going to be an epic cut. The mill is, in truth, very slow. On the other hand I'm growing increasingly confident of setting it going and walking away so speed is less of an issue than it might otherwise seem.
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2014-10-13
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It's Alive! Actually milling things!

I had a restlessness night so I eventually got up and did some nice soothing CAM. Between CamBam for linux at 3am and a late start for work I spent some time cutting wood chips.

This is a wooden holder for Pixel Qi ( wireless inductive) charger electronics. The central circle is <1mm thick, the little "legs" on the turtle shape are for magnets to hold the phone and the tail is for the USB lead. This version of the design is designed to have a C shaped piece of work fit over the back, but I think a veneer would probably work better.

Overall, it worked very well. It took ages (43 minutes) but there are a lot of things I can do to make that faster- I'd guess I can get it down to 15 minutes with two simple changes and probably under 10 minutes. I have a list of things to tweak but it was a very plausible first attempt- and the mill worked perfectly.
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2014-10-08
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