Retrofitting a 1986 Maho MH400E

Good point about using a carbide ball end mill (not like I have one), but in this case the square was made by milling a slot and then welding on the end, so I just repeated that.

Andy, I really like how you make your machine parts and adaptors out of cast iron. As you say in your video, it's traditional. Since the MAHO overarm bolts to the same interface as the vertical spindle, and you have to take it off when it is not used, there would be nothing to gain mounting a high speed spindle to it, other than the prtential to increase the reach in Y direction, allowing engraving on larger panels.



Mark

Speed is primarily limited by the 3TRM2 servo amplifier. As an example Indramat says 3,5 Nm with 2-puls, 4,3 Nm with 3-puls and 5,2 Nm with "SELEKTOR" what ever that is, all for motor MDC10.1020 D. This drive is rated to 150 A max. pulse current. As there is no DC loop with its capacitors, the 3TRM2 can hardly deliver currents near that.
So it should be possible to increase torque by changing the amplifier to a state of the art 4-quadrant brushed motor controller only (but keep the motor temperature in mind!).

Christian

RotarySMP wrote: So I had to chop off the end with the angle grinder and weld on an new tip.

I think that you could probably have got that broken tap out. Normally after breaking off the remains of the tap will break down smaller quite easily if you hit it with a punch from various angles. You have the advantage here that you can get to it from both sides.

I have often wondered how well these work:
www.zoro.co.uk/shop/hand-tools/tap-extra...ractor/ps/ZT1001983X
I inherited one from my grandfather, but have never broken a tap of the specific size.

Good point Andy. I think I have only ever broken one other tap over the years. Given how hard I have been on tooling since I got the MAHO running, I am sure I'll have another tap to extract in the future.

I have been watching ebay, ebay kleinanzeigen etc for a Spindle speeder, or Schnelllaufspindel, Big Daishowa etc. But from what I have been reading, it is probably a better deal to use a separate high speed spindle. The spindle speeders are still going to work the main spindle for quite long periods, and don't have the best reputations for reliablity.

Mark

Spindel Speeders are expensive and a compromise. The 'popular' china spindles are compromises as well but less expensive. All depends on what you want to do.

So maybe a complete new spindle cartridge type with more torque is the way to go?
ATC at the same time maybe?

No ATC for me. Getting the mill up and running was a big goal for me. As I have now sort of reached that goal, I need to work out what to use it for. I really don't have any plans to produce multiples of anything such that an ATC would be warranted.

The MAHO's vertical spindle bearings are lubricated for life, whatever that means. Since mine sat unused for probably 20 years, I have vague concerns about those bearings. Paying €265 for a 1.5kW ER16 chinese HF spindle and VFD seems for the occasional engraving job makes more sense to me that risking the main spindle bearings and a fragile expensive assessory.

Then again I already have a set of P4 spindle bearings I picked up when I was planning to make my own 30 taper mill spindle for my Deckel GiL frame. Maybe making my own spindle would be a good time waster