[hdj80]

Hi all,

Been lurking a few weeks but finally have something to say :-)

I am keen to get a mill and boy is it hard to decide whether to get a small knee style or a square column RF45 clone type. The choice here in Australia isn't quite as amazing as in the USA which makes it a little easier :-)

Anyway I have found a guy on Ebay Aus selling a ZAY 7045FG so 2hp gear head standard dimensions but spec'd up with clamps, vice, collets etc. Not a bad price generally speaking but not brilliant and the model he has seems to have a fairly low top speed of 1250rpm most of the other RF45's here run @ 1600rpm.

However he also advised that he has the ZAY7045FW with a DC motor - so Google being my friend I went and searched the specs. 1.8Kw (so @2.2hp) DC motor with a spind speed range of 50-750, 800-2200r.p.m which seems pretty good.

This model is $300 more.
Now are DC motors good or bad for milling? Will it have sufficient grunt for milling steel at low revs as well as grunt for ally at high speeds? Would a DC version be better if I decide to eventually go the CNC route?

This is the page with the info on models - trhe Fw is available as both AC and DC http://www.zzwtools.com/product/Mach.../ZAY7032FW.htm

Cheers

Craig
Brisbane
Australia

[bones]

Hi Craig,
Is he importing a few or just has one?

Cheers
Rodney

[hdj80]

Rodney,

He says he has a couple of the normal ZAY7045FG's and the ZAY7045FW's.

Any thoughts on the DC motor?
Craig

[Al_The_Man]

Typically the earlier CNC machines DC spindle was common, but these had sophisticated drives with tach feedback etc.
The problem comes with any motor and any drive, if the drive does not have any kind of feedback, even a simple type, the motor will tend to slow under load, the tach for e.g. would indicate to the drive that the motor has slowed and increase the torque required to bring it back to speed.
If you have just a simple control with say pot adjust, if you have any kind of spindle speed display, you can manually increase the speed, either directly through the speed pot, or spindle overide if CNC controlled etc.
Al.

[bones]

Hi Craig,
Could you PM me the link for this guy please.
The DC motor would be good. Servos are basicly a DC motor.
If you fit an PID speed controller you can keep a steady speed and torque like Al said.
I think that would be the better way to do it.

Cheers
Rod

[stueyde]

hi guys

here are some shot of the mills you are talking about $2990 for mill includes 700mm high stand this is a taller stand than usual so you are not bent over so much also 125 wide vice ,clamp set,collet chuck set,halogen work lamp,face mill,and drill chuck all included spindle speed is 2800 rpm max.
these shots are just out of the crate im still assembling this one just to check it out properly so far im pretty impressed how it goes so far ill keep you posted .i only have two of these mills as i just wanted to check them out first over the standard model i also sell.