Handset CAD anyone? :)

Genesis

Anyone need something that looks kinda like this?

(Fits the 4x20 LCD from Parallax.... still have a few more details like lid attachment threaded holes and the O-ring groove for the lid; accepts a DEE-104-A054 Fischer connector on the side for the cable)

The wider base area near the "bottom" is to allow drilling for magnetic switches with the hall effect sensors or reed switches on the inside.....

onetime

Don't need it specifically, but have a general question. How did you learn to use CAD? I recently bought a program and am starting with designing a few things. No doubt I'll work it out eventually but any tips you could share?

Thanks.

--Paul

Genesis

A decent handle on mechanical design and how software works in general is where you start... there are training classes but I've never found them to be of much use.... (big surprised eh?)

I didn't find it particularly difficult to learn; I'm playing with the newer Alibre Design Xpress - their "professional" package is quite reasonable at $1500 (half-off though until tomorrow!) but what I drew this in is COMPLETELY FREE (and not crippled either!) It has some restrictions; 3-d mode freeline drafting is disabled, for example, but in general its real nice and you can't beat the price.

The only "gotcha" on the freebie version is that export is limited to STL files. If your machine shop can "eat" that for CAM that's ok, but if not you've got a problem, especially if they're using something else (the free version can't export AutoCAD compatable drawings, for example...)


My attempt to edit the message to stick in another image failed as time ran out; here's what I was trying to do

steevke

Genesis,

I do these kind of things for a living and the thing you're drawing can't be manufactured easily.

If you are milling, first thing you need to take into account is the diameter of the tool you're using. Typically, you would end up with a minimum radius of 2mm.

The second thing is the maximum depth you can work with your tool. If you're using very small diameter mill, you can't mill very deep.

Before spending a lot of time drawing something up, you need to know what tools they have available in the workshop you will be using and then design according to that. Tools are expensive so needing an extra one is to be avoided at all cost, especially if you just need 'a couple'...

Steven

Genesis

The minimum radius isn't a big deal (the mounting posts are for the LCD display, and those corners aren't important); the depth issue though is....

The other obvious alternative is to forego the posts in the base and put in protrusions in the lid, and screw the display to THAT. That would likely be much easier to machine, now that you mention the issue...... and is no harder to draw up.

Genesis

So if I got it right, what you're saying is that something like this is much easier to machine, due to the lack of sharp corners and no complex inside surfaces (that is, the inside surfaces "fit" the tool - this has all internal corners on a 1/4" radius; ergo, a 1/2" cutting tool should go right to the edge with no "funky" issues.... (put the posts for mounting the display on the lid, thus, they're both short and extrusions from the base material open on all sides, and thus easily accessible to shape with the cutting tool.)

BTW parametric CAD makes drawing stuff like this REAL easy.....

Genesis

Or, to be more precise.... (this should be much easier to machine, if I understood steevke...

steevke

Depends on the tools the workshop has handy Genesis.

Go talk with the guys you will work with and measure the mills they stock & use.

e.g. if you have a mill that cuts 10 mm deep - you need to add a 'stair' or cut under and angle if you want to cut deeper than 10 mm. And then you also need to take the tool holder into account - you don't want to run that into your workpiece.

Your second try looks better than the first, but can't see all the details on the lid so can not be sure if (we) could make it without fiddling.

steven

Genesis

It shouldn't be a problem - there are "prongs" on the bottom of the lid that are for mounting, with a single mounting hole in each.

Here's a couple of additional assembly projections that should show it a little better.

I'm going to send out an RFQ for a handful of these in the next week or so (once I get done fine-tuning it) and see what comes back; I'll post what comes back on the price and if its attractive to anyone and they want in for their own homebuild there 'ya have it.

There's plenty of room for a controller in the bottom if its small; the LCD its designed around is the Parallax 4x20 serial unit; requires only +5V, Ground and a single TTL-level data line. Backlight is controlled with an ASCII code and it is also individually addressible - its a nice unit. The hole in the side is set up for a Fischer DEE 104; I am going to also have the button holes drilled and tapped but need to figure out what I can use for a nut first (I'm trying to avoid having to have THAT machined up, although that one might not be too bad.) My controller and battery are going in a 4.5AH light can, so for my use this is just an I/O device - it would also work pretty well for an integrated PO2 meter, although it might be larger than people would want for that....





Lid material is intended to be 1/2" clear polycarbonate, body either poly or acetyl, depending on price. The dimensions on the actual handset are 5.1 x 3.6 x 2 (all in inches) with 1/2" or better walls throughout. Lid seal is by 1/8" nominal diameter O-ring.

The bottom view is "right side up"; cable exit is on the right. Due to the Parallax LCD having a driver board on the back there is more mounting depth required on the top of the LCD than the bottom; this works out well with room in the bottom for the two ferrules for button guides as well....

divetheworld

Try solidworks, very cool and industry standard. Exports to STL files for rapid prototyping also 20 other formats including dxf, dwg, jpg, pdf etc . You can use the eDrawings program for 3D manipulation without spending the 3.5K on the program.
There are some freebees on my site on the last page.

click here to download a 3.3 meg drawing of a seadoo in eDrawings
click here

Dont miss using the UI interface and doing cross-sections!

__________________