Messages

131

Tangent Corner / Re: Looking for someone with home CNC in Dorset UK

« on: May 31, 2010, 07:58:00 AM »

I'm miles away from Dorset but there may well be local machining shops who could do this work at little cost. what shape apertures are they? size and shape of boxes, number of boxes, tolerances, end use etc. would be useful info. Awaiting your reply

132

Tangent Corner / Re: making a snail...

« on: May 31, 2010, 07:12:46 AM »

I think they just get drunk, fall in and drown. Quite a way to go! also works for slugs, bury a jam jar with 2" of beer in it just up to neck level. In they go, and then it's goodbye to alll that.

133

G-Code, CAD, and CAM discussions / Re: Thread Milling 3flutes - mach3 wizard

« on: May 31, 2010, 06:44:46 AM »

quick update here, replace g03 with g02 if you want a right hand thread 

134

G-Code, CAD, and CAM discussions / Re: Tapered Pocket

« on: May 31, 2010, 06:31:30 AM »

All a question of economics. If you're doing more than a few tapered pockets it would be worth having a tool made. Just a short angled section would do to get a perfectly smooth side very quickly. A ball cutter will take ages and still not make a really smooth side.

Or, you could use a regular slot drill to get a stepped side hole and hand ream the angle if you can get a reamer the right size, or design the pocket to suit the reamer (if suitable for this).

it depends on your needs in terms of volume and accuracy really. Hope this helps

135

General Mach Discussion / Re: cuting snails and helices (helixes?) - parametrics problems

« on: May 31, 2010, 06:01:40 AM »

Cheers Stirling - I was trying to do this yesterday but it was time for dinner and i had to go

Yes, this works for me, and very well, I will save it with my useful snippets of code. thanks.

My thoughts on this are that as bugs go, it's too useful to disregard. I may file a bug report on this and suggest that it be improved to allow an inch or more. thoughts on this? Obviously it could only be used in centre (I J) mode. Any idea what the proposal is for this "feature" in mach4 - remove it to improve compatibility with traditional controls like Fanuc, etc, or reinforce it as a feature, or just keep quiet?

136

Show"N"Tell ( What you have made with your CNC machine.) / Re: What i didn't make with my cnc machine

« on: May 30, 2010, 03:05:30 PM »

happily I've never hurt myself on a mill, but I've tried clearing steel lathe swarf by hand and ended up turning the coolant pink

and this one time* I was using a MIG welder with a sticky wire feed. the arc went up and down, my reactive helmet went on and off, and the flashing light and dark went on for severa hours as I tried to hack the wire feed into life. I felt really wierd when i left, and spent the next two days in bed with the fiercest migrane I've ever had. Well worth avoiding


*no it wasn't at band camp

137

Show"N"Tell ( What you have made with your CNC machine.) / Re: Engine Mounts

« on: May 30, 2010, 02:49:22 PM »

very pimp, nice work

138

General Mach Discussion / Re: cuting snails and helices (helixes?) - parametrics problems

« on: May 30, 2010, 02:35:17 PM »

Hmm. If it's just a happy accident will it remain in mach4 when it finally arrives?

More to the point, is there a "proper" way of cutting a flat helix?

139

G-Code, CAD, and CAM discussions / Re: Thread Milling 3flutes - mach3 wizard

« on: May 30, 2010, 02:24:38 PM »

Not hard to program in any case. Here's an example for an M20 hole using an imaginary 10mm cutter. it's metric too so sub stitute your own values. Usual discalimers apply.

%

g0 x0 y0 (go to the axial centre of the hole at x0 y0)



#1=3.0 (create a variable called #1, value 3)
g0 x0 y10 z#1

g41 (set leftwards compensation for the tool of your choice)
(the first call of the subroutine is an introductory move over the work)

m98 p1 L15 (repeat the subroutine o1 ffiteen times)

g40 (cancel tool diameter offset)

g0 x0 y0 (retract to axial centre of hole)

g0 z20 (pull out to safe Z value)
m30 (finished!)

O1 (start of subroutine o1)
#1=[#1-2.5] (subtract thread pitch value from #1)
g03 x0 y10 z[#1] i0 j0 (mill a vertical helix descending by 1.25mm per turn)

m99 (end of subroutine)
%

I need to get some thread milling cutters actually, they'd save a lot of time. the program here would work with only one tooth but if you had a multi toothed cutter you could drop the cutter most of the way into the hole, then do two subroutine passes (one as an introductory move) to cut the thread.

As i said ... usual discalimers apply ... this should work, but try it on foam first. i would, so you should too

140

G-Code, CAD, and CAM discussions / Re: G-Code Commenter

« on: May 30, 2010, 12:10:25 PM »

That's very nice, like you say it could be a very useful beginner's tool, or for debugging as it would show up silly typos where they exist. Very nice find