Cnc steppers

[Herbiev]

Hi all. I am in the process of converting my rf25 mill to cnc. I have a spare computer, power supply, TB6560 and trial version of Mach3/lazy cam. I was wondering what size stepper motors would be required. I see there are Nema 17, 23 and lots of others but not sure which ones to use.
Tia
Herbie ???

 

[rcfreak177]

G,day Herbie.

The Rf25 mill is quite a beefy sized machine. Depends if you are going to run direct drive to the screws or run a 2:1 reduction or so, I have a Super X3 mill CNC'd and use Nema 23 570 oz in steppers with a direct drive and to be honest it works very well but would be on its limit due to the fast rapid positioning I have set it up for.
I would recommend the Nema 23 570 oz in with a 2:1 reduction or the Nema 34 906 oz in with a direct drive. Also the addition of some anti backlash ball screws, Ebay is a good place to find them cheap.

Here is a link for the Nema 23
http://www.kelinginc.net/NEMA23Motor.html

And the Nema 34
http://www.kelinginc.net/NEMA34Motor.html

This mob is very good to deal with and have no drama's posting to us guy's here on OZ.

Maybe have a chat to Steve at Low Cost CNC retrofits and ask for some advice,
He is very helpful as well and uses Keling Inc for the supply of his steppers too.

Here is a link to the page
http://www.lowcostcncretrofits.com

Low Cost CNC is based in Nerang in Queensland.

Good Luck mate, Please keep us posted.

Cheers Baz.

 

[Herbiev]

Thanks Baz. Thats exactly the info I was looking for. And yes, I will keep you posted

 

[ruzzie]

Hi Herbie
Here are a couple of aussie suppliers that I have purchased through
I bought 2 sets of 3 Axis CNC Kit Gecko G251's, 387 Oz-in Motors, 48V from
http://ausxmods.com.au/ and a jog pendent kit from http://homanndesigns.com/store/index.php?main_page=index and had excellent services from both.

Cheers
Paul

 

[Majorstrain]

I'll second the 387's. I run them direct drive with a Gecko 540 @ 50 volts on the X and Y axis of my converted X3 mill. I also run a 1200oz direct drive @ 80V on the head, but you won't need that.
I have no problem cutting at 1000mm/min.
Cheers,
Phil

 

[Herbiev]

Phil and Paul thanks for the info. Greatly appreciated. Unfortunately, I heard that TB6560s start to smoke with anything over 24 volts. Not sure if its true. Someone that has blown one up might verify

 

[Tin Falcon]

Gecko drives has some great basic info. on sizing motors etc.
http://www.geckodrive.com/ark-2/support.html

 

[Herbiev]

Thanks Tin. Lots of great info there. Reminds me of my telephone technician training days when all switching was done electro- mechanically.

 

[Tin Falcon]

Greatly appreciated. Unfortunately, I heard that TB6560s start to smoke with anything over 24 volts. Not sure if its true

I have heard that too those low end boards are a bit voltage sensitive.
Volts means speed for cnc.
I am running a Gecko 540 with a 36 v PS. on an X-2 mill.
Tin

 

[rcfreak177]

I agree with Tin,
The Gecko drives are defiantly the safest option. I run 4 of the G251 drives at 36v all at once some times with no drama's. My opinion is the Gecko drives are a proven thing through the cnc retrofit community and have had not come across any bad feedback. The G540 unit is handy as it is all incorporated in the one unit and good for 4 axis. Depends how many axis you are going to set up 2, 3 or 4?
Both units are good for 50v.

Have a look at these

http://www.homanndesigns.com/store/index.php?main_page=product_info&cPath=24&products_id=94

http://www.homanndesigns.com/store/index.php?main_page=product_info&cPath=24&products_id=80

Cheers Baz

 

[Herbiev]

Thanks again Tin and Baz. I guess I'm restricted to the low voltage/low speed option with this unit. Having said that, at my age I,m in no hurry to get the job done. Just sit back, crack a tinnie and watch the machine do its magic. When this unit dies on me I will definately look into the Gecko system. For the time being I'm having lots of fun tinkering about and learning heaps with the help from HMEM :bow:

 

[Tin Falcon]

when I was researching CNC I was looking at some of the cheaper options like the Xlotech and others. The G540 was just coming out at the time . I have heard of these low end boards being very voltage sensitive. And I have talked to guys that use them with success.
If you have to sacrifice rapid feed rates that should have no effect on machine use just slower between cuts just make sure you get the feed rates you need. One of the things I remember from seminars with Brian barker of Mach 3/Newfangled solutions is always use calculated feeds and speeds no matter what size machine you have. The depth of cut will vary depending on your individual machine . a Bridgeport can take a bigger bite than an x-2.
Tin