Hello!

Some background at first. I'm Finnish machine builder and I have retrofitted tens of machine couple last years. I got nice Brother TC225 in machine exchange couple months ago. It has "little" problem with it's speed command, it ran to limits with all axes when EM-stop have set off. That problem got fixed just replacing DAC chip (btw, there's pretty weird system for VMCD, same DAC gives speed command for each axis by sample&hold chips, but that's whole different story...), but I looked this little cute machine (I normally make really big ugly ones ) and I think it deserves better than Brother's original controller (even that is for its purpose very nice one). It is really fast machine and idea of somekind of high speed milling test start to develop.

Ok, here's what this machine going to get:

Original servos are X&Y 410W (1.4Nm nominal), top speed 4000rpm (which makes 5mm screw 20m/min rapid speeds). Z seems to be 720W, lead 5mm, original speed 15mm/min, so servo runs 3000 rpm. I firstly thought to use original servos and even solved original servo connector pinout (it couldn't get anywhere!) with scope, but I give up that idea; these Sanyo-Denki motors&drives are 25 years old, and new ones are not that expensive. So new servos would be Delta Electronics ASDA-B2 with 160 000 ppr coders (not really all that resolution is going to used...), Z get 1kW or 1.5kW and X&Y 750W. Both motors runs to up to 5000rpm (nominal 3k), so feed speed increase 20%.

Controller would be Advantech-LNC M628, Fanuc compactile closed-loop controller (3+1+1 axes) which can 4000rpm ridig tapping, 30m/min high speed milling and 60m/min rapid speed. However, without screw replace we can't reach those speeds, so we have to satisfied what we can get with originals. Also even we could run motor like 6000rpm, we probably come another problem, critical speed of screw and G-force what ball screw can stand. Anyways, I think ~4000 rpm tapping speed would give some honour to Brother original idea. I thought 5-axes modification as well, but Brother don't have enough opening or Z-movement for tilt&rotary packet.

Spindle motor is still open. Original permament magnet motor (4.1kW) runs 6k rpm, and I can use Delta's C2000 VFD for running it with no problem, but I really like to rise that 10 000 rpm. Only question is can original bearing handle that speed? Probably not... Brother's manual says there have been 10k spindle as option, but really no descrition of it what is main difference between these models. Is there some coolant unit or pressure lubricated spindle bearings? Second option is induction motor, what I can get up to 10k rpm models. I think I'll go with original way soon as I solve the bearing problem.

Tool changer is really fast its time, but there could make some improvements. Now its works with one phase motor and malta's cross mechanism. I could add there 400W servo and planetary gear if I have enough time from my works (those have to do too :/ ). Tool changer is not problem to get work way or another, controller have internal PLC and macro programming, so that's left hand job.

All electrics is going to make new and correspond European safety standards, what means safety relays, door locks, etc. stuff.

But the machine itself is mechanically good; straight all axes, ball screws and guides are in great shape, even machine's apperance could tell something else. So, I probably not going put this machine totally pieces, just little sandplast and new paint. New controller is little bit bigger than old one, so I'll make new casing for controller at local sheet metal shop.

Here's video (sorry about compressor noise) of the machine and couple photos. I'll get back to business soon as I have something new to tell!

Ps. http://www.cnczone.com/forums/vertic...-retrofit.html looks like Pivotalcustoms making same type machine another side of the globe. Nice Bro, bro! If you reading this we could change our knowledge of Brothers if you like!