Got a quote for £7k can I make it for £500?

**JAZZCNC** · 22-02-2014

Originally Posted by EddyCurrent

So does anyone use a stepper motor to hold the knife so that it can be turned using G code as if it were a 4th axis ?

Yes that's the way Tangential works, Mach as an option to use an Axis for Tangental moves.

Edit: Heres a vid of Tang knife and site to look at with some info. http://www.rockcliffmachine.com/foru...utting-Styrene

http://www.youtube.com/watch?v=aY3h352Lhn4

**Swarfing** · 23-02-2014

Check out this guy who does exactly what you want to do by the looks of it. His machines are quite light weight but adequate for the job and he makes drag knifes also.

DonekTools - YouTube

**m_c** · 23-02-2014

Swarfing, that's the same guy as the video we discussed on the first page. It would appear Donek have more than one youtube account.

**Swarfing** · 23-02-2014

I missed that link so i just checked it out and so it looks like he is into snowboarding as well.

**GEOFFREY** · 23-02-2014

Just for information. This morning I took a blunt 1/8" shank 30 degree engraving cutter, ground a new point slightly offset to the centreline - don't know what the the offset was as it was only done by eye on a green wheel, but probably about 0.3mm and ground the face opposite the flat face down to form a point - I hope that makes some sense. I then used temporary tack adhesive to stick a 0.25mm A4 acetate sheet to a self healing mat, drew a cutting program for 40 of my 1/12 scale streetlamp head glazing panels, edited the spindle start out of the code in the post processor and ran the program. Result? I now have 80 lamp glasses (I ran the program twice). The cut is quite acceptable and the cutter was clearly following in the cut direction and swiveling nicely at the corners. To be fair this was a very simple shape - just a trapezium with the four corners cut back to clear any excess solder I get when building the lampheads. The first sheet I cut at about 1500mm/min and the second at 2000mm/min. I do not think the speed made any difference, but I was trying to hold each cut piece in position as I had used the "tacky" very sparingly so that there was not much adhesive to clean off. There is no noticeable "dobbing" of the corners and no alterations were made to the G code. g.

**Tenson** · 24-02-2014

If the blade can be held freely rotating (I had assumed it needed a dedicated motor) then the CNC3040 could be adapted easily, surely? Just don't power the spindle. If it's big enough that is.

**JAZZCNC** · 24-02-2014

Originally Posted by Tenson

If the blade can be held freely rotating (I had assumed it needed a dedicated motor) then the CNC3040 could be adapted easily, surely? Just don't power the spindle. If it's big enough that is.

Yep I agree and cutting cardboard is a great use for this machine. Still wouldn't buy one my self but yes I agree in this case if he could find a cheap second hand machine then it's worth a stab.!