Beginner MYCNCDIY Mill Build questions

[Boyan Silyavski]

I am not a fan of "ultra cheap" builds as at the end you will have "ultra nothing" as a result and money spend for nothing.

500mm wide working area suggests 2 motors at the long axis that moves the gantry hence 4 axis board. 100-300 euro, i would say 200 euro here only for the BOB. Now if you could avoid somehow this using arduino or whatever cheap. / Saying cheap i don't mean crap Chinese boards without support

Next thing are drivers and motors. if the gantry is No more than say 300mm wide, low voltage drivers and motors are possible/<55VDC/ , for 500mm gantry if you want to achieve normal speeds you will need drivers capable of 70-80VDC and motors 4.2A / 3Nm/ . 4 motors here are 100euro and 4 drives 180-250euro

So you see you have to invest if you want something capable.



But lets start backwards.

What you will 100% need is ball screws and square rails, given the current prices you will save next to nothing using round rails.

So start from the frame, the rails and the ball screws. Cause that you can not change later. When you have money just continue the build.

Take care at the steps below or you will spend unnecessary amount of money due to mistakes

1.Make the drawing
2.Show it here
3.Receive critique
4. Finalize the drawing
5. Buy ball screws and rails.
6. Make frame
7. Buy motors,
8. BOB. drives.....etc.

Hope that helps you to organize your thoughts

[suraj1793]

Thanks for explaining silyavski, I keep on underestimating the scale of these builds...I just see some real good builds and instantly want to try and make them! but I have to start understanding that quality costs money!!!

After re-evaluating my requirements and realizing that wanting a router that can machine both ali and wood is a "typical beginner question" I decided upon a simpler first build. The requirements are, a small 300x300 router that is dedicated to wood work (mainly carving and some involving 40mm deep wood cutting on softer woods). As it would be for carving work I am not trying to hold very tight tolerances, just enough for the carved features to look "right" which I am guessing gives a tolerance of around 0.2mm or maybe even more.

A perfect example of what I am talking about is something like this: http://www.youtube.com/watch?v=OX_Pw8XPYMs
Some of the basic specs are shown here (http://www.busybeetools.com/products...LIVER-CSA.html) this shows that the router uses 240 oz-in motors and just a 150W spindle all of which seems to be closer to my budget than other machines I have seen.

Do you think this is a bit more doable for me with my budget? Like I said, all I am looking for is a decent wood carving router that can be ran continuously.

[Boyan Silyavski]

Ok. I understand.

The example you gave is "perfect" example of crappy machine with good marketing. In fact i have something quite similar and i bought it because there was no body to help then and explain me that:
All cheap systems of linear movement are crap and only the square supported rail is the real thing. So as i said, whatever you do, don't go that way/ v wheels, round rails, etc./ Whatever they say!

So go to ebay or BST Automation and search for supported square rails, Hiwin, chinese or whatever. Just saw that Zapp automation has some great deal on ISEl http://www.zappautomation.co.uk/surplus-stock.html you will need size 20 rails and blocks.


Next you will need to know the ballscrew price more or less, BST Automation

So you decide if its doable or not, just follow the steps from my previous post. Dont start the build until you have the screws, rails and nut housings in your hands.

[JAZZCNC]

Do you think this is a bit more doable for me with my budget? Like I said, all I am looking for is a decent wood carving router that can be ran continuously.

What is your total budget for a fully working machine.?

[EddyCurrent]

From what I've read here, I think you would be better off buying a Chinese 3040 off ebay.

[JAZZCNC]

From what I've read here, I think you would be better off buying a Chinese 3040 off ebay.

Nah I wouldn't.!! . . . I'd encourage him to save up a little more and not waste is money on Rubbish.!!

[EddyCurrent]

Nah I wouldn't.!! . . . I'd encourage him to save up a little more and not waste is money on Rubbish.!!

But that's exactly what he's proposing to do anyway, at least the ebay job is ready built and more importantly saleable again.

[JAZZCNC]

But that's exactly what he's proposing to do anyway, at least the ebay job is ready built and more importantly saleable again.

Not if he's smart and listens to experience talking and while Yes it will be saleable he'll still be losing money.!! . . . . If he saves a little more money he'll get exactly what he want's and when comes time to move on or needs larger machine he'll make money not lose.!

To me that's problem these days every body want's everything instantly but for nothing.!!. . . .Good things come to those that wait.!

[suraj1793]

Hi guys, my budget is around £400-£500. I was initially hoping to build something like this: http://www.mycncuk.com/threads/1541-...-framed-router and work on using it for carving and stuff like this http://www.youtube.com/watch?v=VhKl0...IyoicGWeJ5Z1gQ making use of roller carriages instead of supported round rails as shown here http://www.youtube.com/watch?v=5dmPV7TyzPg as precision is not a high priority for my build but not sure if this is possible with my budget. If not, I would be more than happy with a small router for carving work as shown in my previous post.

As mentioned, I can get box section (both steel and aluminium) and things like fasteners, welding equipment, sheet metal all for free from work. Also, I have an Arduino Uno which could run GRBL and connect directly to the drivers, so might be an option for a controller.

[JAZZCNC]

Well if you get all the steel and fastenings etc for free then you may and it's a very slim chance just about do it. . . .BUT . . . It will be compromised in performance and abilty.!
It will require great attention to detail when building to get even moderate accurecy. The inefficiency or the linear rails etc will require more power from motors to overcome any sticktion. Attention to little details of design like adjustments etc will be needed and you WILL constantly be chasing adjustments.

One problem with the bearing setup shown, and I have built like this so speaking from experience here, is that chips and rubbish become a problem with binding bearings. The bearings wear quickly so need replacing often, on upside they are cheap, but still a pain in arse.

To be honest to build anything like a decent machine that's worthy of the effort involved, which to be in no doubt is considerable, then £1000 is the minium needed to make it worth the trouble. If done correctly then your £1000 will earn it's self back in no time and really will be instantly in profit from day 1 as you could sell it for far more than it cost to build.!!

My advise as always in this position is save up and spend that bit more. Even of you buy a chinese router for £500-600 like Eddy suggest's then you'll end up spending £1000 by the time you have replaced the spindle and electronics when they die.!. . . . And they will sooner rather than later.!!