axeminster micromill stepper motors??

[dickieto]

hi there
i have just bought an axeminster micromill 010061
i havn't picked it up yet but was wondering if these stepper motors would be big enough
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT
or would i need a bigger z axis stepper,just asking as these seem a cheap option for a first build before i tackle a bigger router table!!
have looked at irvings thread about stepper motor sizes but as maths was not my stongest point at school i'll let him do all the calculations:naughty:only joking irving!!
Tom..

[irving2008]

That wasnt the one on eBay by any chance...? mumble mumble... was looking at that myself....

Those motors would probably do the job, although I've not run the calculations. They are 10mH inductance... above 300rpm they are struggling although it is highly driver dependent. I know because I have 4 of them... so we'll need to run the calcs and see... you will need to run them bipolar parallel at 36v or more to get useful work out of them.

[dickieto]

That wasnt the one on eBay by any chance...? mumble mumble... was looking at that myself....

Those motors would probably do the job, although I've not run the calculations. They are 10mH inductance... above 300rpm they are struggling although it is highly driver dependent. I know because I have 4 of them... so we'll need to run the calcs and see... you will need to run them bipolar parallel at 36v or more to get useful work out of them.

oops have i put my foot in it or what!!!!
sorry irving just took a stab at buying it,seemed all right for the money,hope to use it to make model digger parts etc.
theres another already cnc
http://cgi.ebay.co.uk/ws/eBayISAPI.d...=STRK:MEWAX:IT

[irving2008]

its ok, i chickened out at £100... but if i'd known ... what would you have gone to?

[ptjw7uk]

I think they are under powered, on ine I used Arc euro 180Ncm on the x & y axis but ended with 3Ncm on the z axis and that is with all ball screws! I expect using the original screws you get some mechanical advantage but from my original searches most people fitted at least 200Ncm motors some even geared down using pulleys.

Peter

[dickieto]

its ok, i chickened out at £100... but if i'd known ... what would you have gone to?

my max bid was £240 only problem is i live near glasgow!!!
good job i'm going down near seller soon for business..

[dickieto]

I think they are under powered, on ine I used Arc euro 180Ncm on the x & y axis but ended with 3Ncm on the z axis and that is with all ball screws! I expect using the original screws you get some mechanical advantage but from my original searches most people fitted at least 200Ncm motors some even geared down using pulleys.

Peter

hi peter
what kind of material do you mill,and are you happy with your set up.
does it handle alloy ok for small model parts?
if so could you let me know what drivers,motors etc you have?
is there anything you would change???
i'll think of more questions later:naughty:
Tom..

[ptjw7uk]

I mill all kinds even steel, tougher materials just take a bit slower. Only real draw back I have found is the spindle is a bit on the slow side.
I have also added the larger table from Arc-euro, only problem I now have is that using the rotary table plus chuck does not leave much room under the chuck. Back to the design board on that one. I originally went with the 180Ncm steppers from Arc-euro but lost steps on the Z-axis so went with a 3Ncm on there for drivers I purchased a cnc2 unit from http://www.eaziform.co.uk/index.php?products mainly because I dont like the printer port units which rely on the PC to supply all timing signals. The cnc2 unit it is a bit pricey but considering all the infomation I got bombarded with when I started in 2005 I felt it should work out of the box so to speak.
I only wish I had found this forum then I may have made less mistakes.
The biggest mistake I made was to think to hard about most things instead of getting er done as even with the mill running there are still many things to iron out. Simply producing the code is not proving that easy.

Peter