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I has new supply of HDPE

Posted: Fri Feb 08, 2013 5:29 am
by evilvet
I has new supply of HDPE
  • HALO image from Sketchup
    40 minutes of CAD/CAM
    One hour on the mill
    Needs polishing and finishing properly

Posted: Fri Feb 08, 2013 6:50 am
by Zeus
Looks good mate, if you need to just smooth it over a bit, just running a heat gun over it should slick it up a bit.

Posted: Fri Feb 08, 2013 7:01 am
by evilvet
Yeah, heat gun or a Dremel with a sanding drum is the current option.

My longer term plan is to add a fourth axis to the mill, then all is good.

Right now i can do pretty much any regular solid, if it has a symmetric axis in at least one plane then all is good. i create the part as a 3D object then split it into two halves, after milling they are glued or screwed as shown into a complete unit.

The process is pretty straightforward.
  • Create or acquire the object as an STL file
    Load it into CAM and perform a series of X axis slices at the range of 1-2mm depending on the level of detail required
    Delete all polylines below Z=0
    Create MOP's to suit the remaining polylines
    Copy and past the result and then do a Y axis transformation on the copy
    Edit the Z axis points on the copy to create two "flat" 2.5D results
    Machine then laminate

Crude but effective.

Posted: Fri Feb 08, 2013 7:37 am
by jackssmirkingrevenge
noice!

This is for "Apocalypto"? :D

Posted: Fri Feb 08, 2013 8:09 pm
by evilvet
Yep
Stock is next, I think I need to add a fourth axis sooner rather than later.

Anybody got a lead on a cheap self-centering chuck they want to sell......

Posted: Sat Feb 16, 2013 6:34 am
by Zeus
JSR's spark gap came it, and I can't recommend him enough, excellent quality, checked the electrical leakage at 500 volts, absolutely nothing. Still sparks with a grill piezo igniter at 23 bar. Haven't had a successful shot yet, but that's just because I haven't really tried.

The only suggestion I have (which I forgot in the PM) was to back out the tap a bit more often, doesn't affect it at all, you just see some tiny little burrs. Either that or it's a little bit dull, but it's no problem.

Posted: Sat Feb 16, 2013 6:54 am
by jackssmirkingrevenge
For some reason this particular tap is a bit iffy, I never managed to get fully satisfactory results with it. One eighth BSP would have been prettier, but as I understood less convenient for you.

Updated my 3D modeling software

Posted: Mon Feb 18, 2013 12:53 am
by evilvet
And fabricated a jig that allows me to flip a part accurately around the XYZ centre.

And the first result is..........

A 1/4 scale model of a 62 Stratocaster.
I have a couple of mates into their music in a big way so did this for a laugh.

Posted: Mon Feb 18, 2013 1:54 am
by jackssmirkingrevenge
tres cool! is that wood or foam?

You know, many members on here would pay good money for CNC cut stocks...

Posted: Mon Feb 18, 2013 7:15 pm
by evilvet
It's MDF, 16mm stock.

Something like this maybe.

Happy to make one up for testing purposes, anybody got some suggestions ?

Maximum dimensions would be 600mm long and no more than 40mm total thickness. The obverse and reverse can have different detailing, even engraved lettering if that floats your boat.

The main issue is getting a suitable 3D model. The one below was taken from a Google Sketchup model of (allegedly) a Remington 700, then exported as an STL format file for CAM processing. Each surface generates about 80,000 lines of code for the CNC mill to chew on. I can produce something to about 0.1mm accuracy, that's about 4 thou for you non-metric types, the result really depends on the tooling and the material.

Posted: Tue Feb 19, 2013 12:54 am
by jackssmirkingrevenge
There are plenty of folks handy with 3d here so I don't see modeling being a problem.

Here's a thought, how about designing a starter kit for noobs?

An eBay shopping list with cheap QEV, blowgun pilot etc. and a clamshell CNC stock to go with it which holds everything together...

Posted: Tue Feb 19, 2013 12:59 am
by evilvet
Yeah, great idea in Oz with our gun laws. :shock:

Hey Zeus, wanna be cell buddy with my new best friend, the 150kg Islander with a poor hygiene plan.

No thanks, I will machine bits of plastic for toys all day long, or even wooden gun stocks so the kids can play cowboys and Indians; DIY free trips to the County Court, no thanks.

Posted: Tue Feb 19, 2013 1:34 am
by Zeus
What, you expect me to hold him down while you...

Ahem.

Distribution is no concern within Aus, I'd be happy to take care of that at cost. But we've been discussing something a bit lower risk, and higher return.

Posted: Tue Feb 19, 2013 2:12 am
by jackssmirkingrevenge
evilvet wrote:No thanks, I will machine bits of plastic for toys all day long, or even wooden gun stocks so the kids can play cowboys and Indians; DIY free trips to the County Court, no thanks.
I don't think it's as risky as you think.

First off, it's a piece of wood. You can't be prosecuted for mailing someone a piece of wood.

Secondly, there is a whole world beyond Australian borders that you can sell to without legal concerns.

My idea would be to draw up a list of parts that can be easily and cheaply purchased online in order to make something like this:

Image

Dewey would naturally be a huge help here :)

All that would be left is to design a stock, something in two halves with grooves to accomodate the worky bits in between.
Zeus wrote:lower risk
Very out of character ;)

Posted: Tue Feb 19, 2013 2:49 am
by evilvet
VICPOL Official:

From 1 July 2011, an imitation firearm will be defined as "a device, the appearance of which could reasonably be mistaken for that of an operable firearm, but which is not designed or adapted to discharge a shot or bullet or other missile by the expansion of gases produced in the device by the ignition of strongly combustible materials or by compressed air or other gases, whether stored in the device in pressurised containers or produced in the device by mechanical means and is not capable of being made to do so".

Have a read of this
http://www.police.vic.gov.au/retrieveme ... tus=active

and welcome to our world.