Messages

91

General Mach Discussion / Re: Tormach type toolchanger that actually works!

« on: January 29, 2014, 12:13:08 PM »

I dont know of anything else there called

92

General Mach Discussion / Re: Tormach type toolchanger that actually works!

« on: January 29, 2014, 11:32:08 AM »

http://www.ebay.co.uk/itm/Precision-C20-ER25-50L-Straight-Shank-collet-chuck-holder-20mm-diameter-tools-/161159455553?pt=LH_DefaultDomain_3&hash=item2585da2341

You can turn the tapers on with a carbide tip with these
 The collars are just parted off steel bar with grub screws or I heat shrink them on its best just to skim the collar on the spindle side after fitting to ensure they pull up true.
Tony

93

General Mach Discussion / Re: Tormach type toolchanger that actually works!

« on: January 29, 2014, 10:48:11 AM »

I actually make my own arbours either turned or I buy in Chinese 20mm parallel er arbours and then attach a collar to them, that's the cheapest way of doing it.

While im here I have  actually placed a European registered design notice on the double taper lock , I don't mind individuals building there own systems, but would take a dim view of people taking commercial advantage of this Method with out first contacting my company Horton Engineering.

94

General Mach Discussion / Re: Tormach type toolchanger that actually works!

« on: January 29, 2014, 03:23:20 AM »

OK I have reground the r8 taper on the collet to approx. 17.5 deg (giving it an extra 0.5 deg a side) this is to pull the tapers up parallel in the locked position. This has made another huge difference! I put a 12mm cutter in with not a great amount of drawbar pressure and could push it thru. aluminium at a rate that actually stalled the spindle and still it neither pulled out nor slipped. so I would say that's as good as its going to get for now.

95

General Mach Discussion / Re: Tormach type toolchanger that actually works!

« on: January 26, 2014, 11:32:49 AM »

well the tapers i cut using freshly sharpened carbide cut it a treat.
If you wanted to use a toolpost grinder then you would dress the periphery with about a 5 deg angle and tap the grinder 5 deg off 90. that would give you the clearance.

Tony

96

General Mach Discussion / Re: Tormach type toolchanger that actually works!

« on: January 26, 2014, 10:35:26 AM »

Dave no its nothing to do with contact area,its about in effect "wedging" or locking the arbour into the r8 collet.
at present im using a standard r8 collet but im going to have a play with grinding the collet a teeper angle to ensure it pulls up parallel on both tapers.
although it seems ok as is.

Poppabear thanks for the complement I hope it helps people out

97

General Mach Discussion / Re: Upgrading question 32bit vs 64bit, USB vs Parallel , Mach 3 vs Mach4 HELP!

« on: January 22, 2014, 12:55:01 PM »

I use a uc300 usb controller from cncdrives there very very good and reasonably priced

98

General Mach Discussion / Tormach type toolchanger that actually works!

« on: January 20, 2014, 03:59:16 PM »

After spending many hours designing building and setting up to work like clockwork,a tormach type parallel arbour, carousel changer, can you imagine how I felt when all I had was a poor cnc drilling machine? not good!
  Like many before me (who I chose to ignore) I found that you really cant get enough pressure on the r8 collet to hold the 20 mm (in my case) arbors,to get any where near you have to have to have a huge amount of pressure to release it. the best performance thru. alli was 10mm deep with a 10mm dia cutter anymore than that and the whole arbor pulls itself out of the collet. A well documented problem ! Any more drawbar pressure and it seems like a bomb waiting to go off!!
    So it all languished there hanging of the side of the bf30 gathering dust. This morning it occurred to me that if you put a negative angle on the arbor then the r8 collet will over travel into the negative and not allow the arbour to pull out. A little bit of maths later came out with a 1 degree included angle. Sure enough it locks in a treat plus i bet i haven't got half the pressure on the draw bar now!! Happy days!! ,well till the next "challenge"

Tony

99

General Mach Discussion / Re: uc300 usb controller

« on: January 13, 2014, 06:13:16 PM »

Well I can highly recommend a uc300 now Ive bought one, very very simple to set up and Balazs at CNC drive gave fantastic service once more! If your thinking of getting one you will not be disappointed.
 Tony

100

General Mach Discussion / Re: Spindle parking with mach ideas please

« on: January 07, 2014, 08:46:25 AM »

been toying with this for my toolchanger, thinking along the lines of the spindle stops and a dc motor engages it and turns spindle to an optical switch, and orientating it for the drive dogs,im using using a tormach type system with a carosell but quit frankly its useless for anything other than drilling or light milling. need a bt30 solution.
Tony