Machsupport Forum

Mach Discussion => FAQs => Topic started by: 9ale7 on August 15, 2010, 08:40:16 PM

Title: newbei: what to buy for my 1st CNC ?
Post by: 9ale7 on August 15, 2010, 08:40:16 PM
" maybe this is the wrong forum but it do say FAQ :) "
hi,
this is my first topic while i try to build my first CNC.

i'm looking into many websites trying to find what I REALLY need to start a CNC for a hobby,

so i saw this on ebay:

(http://img.easysupply.xories.com/PKG/001653/001653.jpg?1278471168)

for now lets us say, i have a table and a miller,

so do i need also divers for the steppers motor? like here:
(http://img.auctiva.com/imgdata/1/4/2/2/0/7/2/webimg/384820800_tp.jpg) 

what about the homing and limit switches?
emergency  button?

everything you say can help.

NB: i know that i'm suppose to look in the websites that teaches how to build a CNC, but i believe the response here will more from experienced users.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: RICH on August 15, 2010, 10:49:12 PM
Start reading and researching a lot. Spend once and don't do it twice......
Take a look at different cnc machines by manufactures of the type you will be using.
If your handy you can minimise investment and save a lot.

You will need a computer, a controlling program like MACH, a controller which contains the power supply / drives, etc , a purchased machine or
one you can convert.

Have a look at what folks have built and posted on the site.

RICH
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: Tweakie.CNC on August 16, 2010, 04:39:07 AM
I spent quite a long time reading the postings on this site before building my own machine from scratch. The first thing that I noticed is that everybody does things differently, there are no two machines exactly the same which is great. This means that there is plenty of scope to personalize your own machine to your own needs and yet still have an accurate and reliable result. Just keep collecting others ideas then apply the best to your own machine.
Incidentally I have had good results with the cheap Chinese driver boards (4 machines to date) they are cheap enough to be throw away items if anything goes wrong but for long term reliability, value and good back-up service the Gecko stuff takes some beating.
Take a look at my website, it may give you some ideas. http://www.cooperman.talktalk.net/

Good fortune with your build.

Tweakie.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: 9ale7 on August 16, 2010, 08:45:27 AM
thank you for the respond,
ahhh..looks like this is going to take a long time :P
my problem was as did tweakie mentioned, there is no " one way"  to do it, all the website use their way and their stuff.

but still i would like to see any links or examples on how to do it starting from the scratch.

and to Tweakie:
did you hear about BAD Result of the Chinese boards and motors, because i do intend to use them???
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: Tweakie.CNC on August 16, 2010, 09:20:48 AM
Quote
and to Tweakie:
did you hear about BAD Result of the Chinese boards and motors, because i do intend to use them???

Oh yes - there are plenty of bad reports on all Chinese stuff but I think that if you buy ebay the suppliers want to maintain a good rating and don't send you the rubbish.

Perhaps I have been lucky, perhaps you will be lucky also  ;)

Tweakie.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: 9ale7 on August 16, 2010, 07:05:06 PM
well that's a good thing to hear, because i intend to from ebay.

and please can you answer this,

in the second picture above there are 3 drivers board (plus the main board which connect to all of them) which the same seller said i don't have to use if i needed to build a CNC (but they can increase the accuracy of the machine)) ,
is he right or wrong?

again thanks for the reply.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: Tweakie.CNC on August 17, 2010, 02:28:57 AM
All the new driver boards these days incorporate 'Microstepping' http://www.cooperman.talktalk.net/files/13.htm (http://www.cooperman.talktalk.net/files/13.htm) which allows a motor with say 200 steps per revolution to achieve say 200 x 8 steps per revolution. This is really a theoretical resolution increase because 'microsteps' are not that accurate but they do make for smoother motor running and probably better performance. I have not found any benefit to go above 1/8 step (which gives me a maximum theoretical resolution of 0.00625mm) but 1/10 or 1/16 may offer something. For a first build I think I would go for the cheapest option.

Hope this helps.

Tweakie.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: 9ale7 on August 18, 2010, 08:14:56 PM
thanks for the tip, and you're Tweakie....nothing but a WOOW :P

and i found two other questions:
what is the red arrow ( i suppose the blue arrow is the 3 axis borad)?
(http://img411.imageshack.us/img411/5199/28972560.jpg)

and what is 1 and 2 ? they are related to power,

(http://img256.imageshack.us/img256/7247/55512226.jpg)

are they
- http://www.alliedelec.com/search/productdetail.aspx?SKU=967-8482&SEARCH=&MPN=F-401U&DESC=F-401U&R=967-8482&sid=477C25805B15617F (http://www.alliedelec.com/search/productdetail.aspx?SKU=967-8482&SEARCH=&MPN=F-401U&DESC=F-401U&R=967-8482&sid=477C25805B15617F)

and

http://www.mpja.com/prodinfo.asp?number=7846+TR (http://www.mpja.com/prodinfo.asp?number=7846+TR)

again thanks for the greeeeeat help
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: Tweakie.CNC on August 19, 2010, 01:32:06 AM
Red arrow indicates the junction board incorporating pull up resistors used for terminating my limit switch wiring.
1) Solid State Relay used initially for switching the spindle motor but can be used for anything.
2) Rear of 3 pin socket for connecting items that will be switched by the SSR.

Hope this helps.

Tweakie.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: RICH on August 19, 2010, 05:55:50 AM
Is that a schematic on the case cover below the arrows you have drawn?

RICH
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: Tweakie.CNC on August 19, 2010, 07:25:14 AM
Sure is Rich.

When you do these things and it is all fresh in your head you don't need a schematic but a few years down the line .......
I got the idea from some other machine photos I saw here somewhere.

Tweakie.
Title: Re: newbei: what to buy for my 1st CNC ?
Post by: RICH on August 19, 2010, 07:12:50 PM
Opps, I thought is was 9ale7's controller box, guess I should go get another ale or lager....... ;D
RICH