Newbie- Recommended Material to Make an CNC Machine

[samsagaz]

Hi guys, im planning to purchase 3 Nema34 Steppers with like 800Ncm each one.

im looking some good material to make the machine, i think that MDF will not support the 3kg of each motor.

What Abt Aluminium? Can someone please help me?

THanks in advance

[Crevice Reamer]

Those are about 1200 oz steppers. What kind of machine is this? Why do you need such large motors?

How big is it and what kind of drive will it have? What kind of Rapid performance are you looking for? What will you be mostly cutting?

CR.

[samsagaz]

Thanks for your fast answer.

Machine will be small, i want it for mainly 3 materials.
1 Create small PCB design for personal use
2 Work with brass and aluminium
3 Work with Steel.

i already own 4 LM THK SR25 (New) 4 LM THK SR20 (used 8/10 points)
2 guides for the LM SR25 of 46cm, 1 guide for the THK SR20 of 41,4cm, and 1 guide for the THK SR20 of 41,6cm (2mm of diference).


Maybe i can purchase some small stepper too, but dont know if 600Ncm or small will be OK to work with Steel.

[Crevice Reamer]

This started out sounding like you were constructing a router. Is it a mill then? Are you going to be using ball screws or Acme for lead screws?

Small is not an answer. What is the work envelope going to be? You could not mill steel very well on a machine made from MDF. It would not be either rigid or accurate enough.

CR.

[samsagaz]

Well i want to Mill PCBs and route metal and wood.

i will use THK Ball Screw but dont purchase it yet. i want to use the components tha ti already own, so table will be like 46x42cm (its the size of the Linear Guides that i already own)

its the problem i dont know what material to use to get acurrancy enough and be rigid.

[Crevice Reamer]

Your table dimensions would be 1 5/8 inches by 1 1/2 inches--That can't be right.

You will have to decide whether you need this more for wood/aluminum or steel. You can't have both.

PCB boards need tiny drills and high RPM spindles, Wood and aluminum routers need high RPM spindles. STEEL requires very rigid low speed spindle.

CR.

[samsagaz]

CR i really dont understand why you say that the table will be 1 5/8 inches by 1 1/2 inches

With the guides that i have i will get like 18 x 16 1/2 Inches!

Ok, i will go with the Wood/Alu ones, and after that maybe later will build the steel one. If i cant work with the three materials in the same machine.

[Crevice Reamer]

Originally Posted by samsagaz CR i really dont understand why you say that the table will be 1 5/8 inches by 1 1/2 inches With the guides that i have i will get like 18 x 16 1/2 Inches! Ok, i will go with the Wood/Alu ones, and after that maybe later will build the steel one. If i cant work with the three materials in the same machine.

Originally Posted by samsagaz Well i want to Mill PCBs and route metal and wood. i will use THK Ball Screw but dont purchase it yet. i want to use the components tha ti already own, so table will be like 46x42cm (its the size of the Linear Guides that i already own) its the problem i dont know what material to use to get acurrancy enough and be rigid.

OK then. I guess you meant to write 460 cm by 420 cm.

Those motors will be WAY too big. Maybe N23 270 oz (236 N cm) would be more like it. And you COULD build this out of MDF for wood and aluminum.

CR.

[samsagaz]

Originally Posted by Crevice Reamer OK then. I guess you meant to write 460 cm by 420 cm. Those motors will be WAY too big. Maybe N23 270 oz (236 N cm) would be more like it. And you COULD build this out of MDF for wood and aluminum. CR.

Ok, will check prices for small motors. Wich design you recommend me in MDF to cut wood? what about brass? that motor will be ok too?


460cm = 4,6 mts = 181 Inches
and
420cm = 4,2 mts = 165 Inches

[Crevice Reamer]

I'm Not sure about brass on a router. I don't really know if it is feasible. I don't think so though.

Has anybody else ever cut brass on a router?

Approximately 25 centimeters per inch. 420 centimeters is about 17 inches.

CR.

[samsagaz]

Originally Posted by Crevice Reamer I'm Not sure about brass on a router. I don't really know if it is feasible. I don't think so though. Has anybody else ever cut brass on a router? Approximately 25 centimeters per inch. 420 centimeters is about 17 inches. CR.

ok, thanks for your support, hope someone can give us some other ideas for now i think that will lower the motors


1 inch = 2.54 centimeters
1 inch = 25.4 millimeters

[Crevice Reamer]

Whoops! I must be tired. You are absolutely right about the centimeters!

CR.