Messages

1981

General Mach Discussion / Re: THC moves on the Z axis...

« on: February 13, 2016, 07:01:38 AM »

Spent the morning ripping my Z axis apart to replace the 10x2 screw & nut with a 10x4 combo.

This seems to have helped but my question is this - it now has the ability to be tuned from the previous 1500mm/min to 3000mm/min easily so should i take advantage of that or will make the problem return?

I currently have it set at 3000mm/min speed and 3000mm/s/s acceleration and it works fine during tests but have not done any cutting yet.

Steps per was a simple change from 1000 to 500.

It is a heck of a lot more snappy though I reduced the Z probing rate to 20% for the last portion of the G28.1 routine.

Another fantastic revelation was that because I have a probing subroutine now, I only had to alter the switch offset in Mach and it was back to it's accurate IHS in seconds - no messing with code changing etc

1982

General Mach Discussion / Re: Educational Sources???

« on: February 13, 2016, 06:52:19 AM »

Ok, found it, little expensive but sounds good, will order a copy.

1983

General Mach Discussion / Educational Sources???

« on: February 13, 2016, 04:16:42 AM »

Hi all,

Having embarked on building a CNC router/mill of around 400x500mm size, and so far only having knowledge of 2d CNC in plasma cutting I realise I have a pretty large gap in my knowledge base  

With all you multi-talented types on here, can anyone point me to a resource that would help bridge the gap between CNC plasma cutting and CNC milling - I have no idea about cutter compensation, homing (plasma is always top of material), cutter length, tool height setting, tool numbers etc.

Some sort of CNC mill primer??

Youtube is loaded but mostly not relevant stuff or presumes knowledge already.


Thanks

1984

General Mach Discussion / Re: CNC mill has mind of it's own

« on: February 10, 2016, 12:34:33 PM »

Safest to copy the whole Mach3 folder to a usb stick - no chance of losing a file then.

1985

General Mach Discussion / Re: Mini-Mills - any good???

« on: February 10, 2016, 12:32:37 PM »

Scrub all of that, bad idea

Been chatting to a builder that sells these things and got enough help to get going now.

Motion control...

Stick with parallel or go with my feeling of using something like a UC100 motion controller???

1986

General Mach Discussion / Re: Mini-Mills - any good???

« on: February 09, 2016, 10:28:04 AM »

Thoughts during tea break....

My want is for a general purpose machine - wood, alloy, plastic, engraving, carving, milling, working envelope maybe 400mm x 500mm.

Now, I see plenty of builds with 100's of kg of steel in them, but for such small cutters, is it really needed or is it "just the norm" ?

Picture if you will, no box-section, use maybe 15mm x 150mm or 20mm x 150mm aluminium to make a shoe-box structure - 4 sides and a base (base can be thinner i think).

Mount 15mm HiWin rails to the tops of the long sides, 2 carriages on each side. Mount 1610 ballscrew on outer side of longer sides.

Make gantry base to span the opening, deep enough to take two carriages suitably far apart, drop plates down from ends to fix ballscrew nuts to - it would be an inverted U shape.

Build gantry as required from base up to hold Y axis and Z axis and brace down to base of gantry at rear.

Basically just build the whole thing from a slab of alu and screw it together suitably.

Probably just hogwash, but can you really get that much counterforce etc from such a small tool???



As i say, just thoughts, no bank balances were damaged during this process

1987

General Mach Discussion / Re: Mini-Mills - any good???

« on: February 09, 2016, 07:00:45 AM »

Yeah, got that, space is very important so will be leaning towards moving gantry.

1988

General Mach Discussion / Re: Mini-Mills - any good???

« on: February 09, 2016, 04:44:59 AM »

Like i mentioned earlier if you want a great do everything machine build a fixed gantry mill . It can do everything to a point.

(;-) TP

Thinking a little more, a fixed gantry/moving bed puts the motion for the bed in the dirt/coolant zone, ok on a big machine but probably dodgy on a small unit??

I was looking at an X/Y gantry with the rails mounted way up under the gantry so no side support columns on the gantry.

Dredging through the suppliers on Aliexpress, it looks like I'll get 3 sets of 600mm 1610 screws/nuts/supports and some 1m long HiWin's and just build the machine around the motion, it's far cheaper than getting custom lengths and easier than machining the ends of the ballscrews myself.

1989

General Mach Discussion / Re: Mini-Mills - any good???

« on: February 08, 2016, 10:58:45 AM »

Also very easy to convert to a 5th axis machine (;-) I know you want one (;-)

\

5?

having enough getting to grips with three

1990

General Mach Discussion / Re: Mini-Mills - any good???

« on: February 08, 2016, 10:57:59 AM »

Like i mentioned earlier if you want a great do everything machine build a fixed gantry mill . It can do everything to a point.

(;-) TP

So that would be fixed gantry and moving bed?

Assume bed moves in 1 axis and the other axis is carried on the fixed gantry?