alan2525

I've got a couple of engraving bits, one 90 degree and one 120 degrees. I set the depth so it cuts almost through - leaving about 0.2mm remaining. a touch of liquid poly tacks the joints at the correct angle and a bead of poly cement run along the inside provides the strength.


The software I use is called Pro Desktop and I generate the development using Pepakura, a piece of japanese software used to create card models from 3d CAD models. Solidworks will also do the same thing but I've yet to install that on my PC.

The resulting assemblies are very pleasing as being cnc cut fall into place with barely any additional work on the edges needed. I also drill the holes to allow for the parts to be aligned using needlework pins whilst they are glued together. Parts where access are needed will actually use very small BA screws to allow dissasembly too.

I'll also machine some parts at the correct angles where angles other than 90 degrees are needed where the thickness of the material is significant or where you will see both sides of the piece, a gunshield for example.

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rjwood_uk

do you have all this stuff at home alan? or do you take advantage of st.marys equipment? lol

Richard

alan2525

I used to try to use the equipment at St Mary's but it's so awkward trying to plan for everything and do modelling jobs during a lunch hour or something. I bought my own CNC Engraver and it's great fun and superb for modelling.

It's small in capacity only 210 x 310mm bedsize it wont be any good at machining a cylinder head from an old escort or anything but it'll cut hardwoods, pcb's, plastics, laminated plastic name labels, it'll machine and engrave brass and cut brass shim, but one thing that is very useful is when working on thicker pieces you can use it to accurately scribe and mark out pieces to be cut, position hole centres for gearboxes etc. A brilliant bit of kit.

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Bunkerbarge

Superb job Alan and very interesting techniques. Thanks for the descriptions and pictures.

noobee captain

Alan,

taking shape and looking good!

alan2525

Here's some images of the little tracked chassis I built to test the drivetrain and control conponents.

I'm using Tamiya Gearboxes at present and although I've been told the mabuchi motors (toy type) are ok for 6 Volts I've already cooked them much to the cat's glee!

I was amazed by the battery duration though as I'm running it from 5 AA NI-Mh pen cell batters and using BEC.

All the drive spins freely and with the gear reduction of 58:1 or so I would have thought those motors would have been up to the job.

I think I'll have to purchase something heftier and redesign the final drive, the only problem will be trying to fit the gearboxes in to the width of the tank, which will only be 70mm or so in width.

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