I NeeD HeLp PLease AM882 a good choise

[jpsicilia]

Here are some old frame renders

[JAZZCNC]

Here are some old frame renders

Hope this is just initial draft because You will need many more supports and bracing adding before this design is usable.
Also it's too wide for a central ballscrew and you will never successfully cut aluminium, or wood for that matter with this design. ABSOLUTELY must have TWIN ballscrews.!!

[jpsicilia]

How are you Jass? You are amazing! You have clarified many doubts for me. I hadn´t considered the pitch before and the quality it brings. As you said, it is true that we think that the bigger the engine the better. It is very interesting your idea of changing the ratio of the pulleys to get more resolution or speed and considering the torque. With all the information you gave me I have decided to restart my project. I will remodel these aspects with the solidwork software and I will most probably ask you some questions if you do not mind. Thanks a lot!!

[jpsicilia]

Hello again! As I have told you before I have started with my CNC project from zero thanks to the tips you have given me. I thought of making a bigger CNC, use it to mill wood, plastic and aluminum, and later I want to buy a small mill and change it so that I can build mould in aluminum and if possible metal.
This time I am bothering you because this week I am going to buy the components from China and I want to make sure that I am buying them correctly, and I imagine this happens to all of us when we build a CNC for the first time. I have a couple of questions regarding the hgr15 for the x axis, maybe they will work or will I need a hgr20?
This is what I have thought for the CNC:
Axis X
2pcs RM1610-1500mm Full length 10 pitch with ballnuts and end machined.98 usd
2pcs HGR15 -L1500mm Linear Motion Guide Rail with 4pcs HGH15 Narrow linear carriages 200usd
Axis Y
1pcs RM1610-1200mm Full length 10 pitch with ballnut and end machined.45 usd
2pcs HGR15 L1200mm Linear Motion Guideway with 4pcs HGH15 Narrow linear carriages 176 usd
Axiz Z
1pcs RM1605-350mm Full length 5 pitch with ballnut and end machined. 26 usd
2pcs HGR15 L=350mm rail with 4pcs (HGH15 Narrow linear carriages)108 usd

Motors
5PCS Nema 23 stepper motor 425oz-in,3A,2ph,1.8° CNC Engrave 241uss
Timming Belts?
Witch timing belts and pulleys do you recommend?
Drivers and supply power?
I have the same problem as before, I believe that you can help me with this. I have researched on these products, what do you think? Is it an analogic driver convenient or a digital one?
1pcs 6 axis cnc breakout board DB25/ interface board adapter milling engrave c10 18uss
DM542A
Mt880.
Same pictures of the cnc frame

[Jonathan]

I have a couple of questions regarding the hgr15 for the x axis, maybe they will work or will I need a hgr20?

Either is plenty stiff enough. Sometimes people go for the 20mm rails just to make it easier to to make the parts they mount to with minimal machining. You need to draw it and work out which is best before buying them.

Motors
5PCS Nema 23 stepper motor 425oz-in,3A,2ph,1.8° CNC Engrave 241uss

Don't get those. They're 3A/phase which means they're the higher inductance motors. You want motors with lower inductance to get more torque at higher speeds - just search this on the forum and you'll find more detailed explanations. Last time I checked, these were the best value.

Timming Belts?
Witch timing belts and pulleys do you recommend?

HTD 5m (i.e. 5mm pitch) and 15mm belt width. Don't get bigger pulleys than you need to as it'll adversely affect the acceleration. You can get them from Bearing Station, belting online or aliexpress.

Drivers and supply power?
I have the same problem as before, I believe that you can help me with this. I have researched on these products, what do you think? Is it an analogic driver convenient or a digital one?

The 'digital' ones should be better than the 'analogue' ones, but it's a bit of a misnomer as they're all digital to an extent. Drivers like the AM882 use better algorithms (e.g. field oriented control) to get slightly higher torque from the motors and detect stalling, among other things. However once you've tuned the system properly it wont stall, so if you can get enough torque with a cheaper driver (e.g. DQ860MA) I see no reason to get the better ones.

[JAZZCNC]

I see no reason to get the better ones.

I see a reason.!!!!. . . . They are better.!! . . . and the price difference is not enough to justify not taking advantage of there more advanced features like better resonance handling and stall detect. Has you well now there are other things beside incorrect tuning which can stall motors and on dual screw machine having the ability to alert and E-stop the machine is worth the slight extra cost IMO.

Oh and from the few times I've used the DQ869MA the AM882 give much smoother performance from the motors at lower feeds.!!

[EddyCurrent]

Juan,
Have a read on this thread about the frame design.

http://www.mycncuk.com/forums/router...-please-3.html

[Jonathan]

I see a reason.!!!!. . . . They are better.!! . . . and the price difference is not enough to justify not taking advantage of there more advanced features like better resonance handling and stall detect.

Just because something that it better is available doesn't mean you need something better. The machine will run perfectly well with DQ860MA drivers.
The cheapest AM882 drivers on aliexpress are currently £56.18 each, versus £37.65 for the DQ860MA. In my opinion it's not worth the extra £18.26 when the machine will be fast enough with either.
If concerned about stalling, then by all means get two AM882 drivers for the X-axis, but save £36.50 and get cheaper ones for Y and Z.