Need Help!- A few questions to start a DIY mini CNC

[Purple_rob]

Hello all,

I only thought about building a mini cnc last night and have only spent about an hour looking around the net at ideas.

I did'nt really get anywhere but have a few ideas and thought i'd post a few questions to see if what I want to achieve is even possible.

I'm looking at building quite a small CNC to enable me to machine materials such as: hard resin, nylon and possible small quanities of aluminium.

This is hobby only and I want to make it as simple and cost effective as possible for my first build to get good ideas and improve if necessary.

I am happy I am able to build the frame work but need to know about Hardware and Software

OK Questions,

1. If I was looking to purchase some cheap stepper motors from ebay (UK) what would I be looking for?

2. How would I match these motors to the controller and what controller would I be looking for? (how would this connect to my PC)

3. For a novice in software could anyone recommend anything?. Is there any freeware around?

4. Lastly, there are a lot of DIY builds on you tube and i'm quite impressed. I could'nt find any DIY designs on this site, are there any?.

Many thanks to everyone in advance, this site looks pretty amazing and I'm quite excited about starting a project.

Thanks Rob

p.s My apologies if this is in the wrong section of the forums.

[irving2008]

Rob,

If you're UK based why not come and join us on www.mycncuk.com The Zone here is a great resource but the other site is more UK specific and theres a small but growing bunch of enthusiasts there who also are to be found here too

Before you can select motors you have to have some ideas about size and performance of the machine they are going to be driving, what linear motion arrangements and drive mechanisms. These will determine the torque and speed needed and therefore the motor. That will then determine what drivers might fit the bill...

[Purple_rob]

Thank you, I will try on there but all answers welcome

[TOTALLYRC]

Several questions come to mind.
1. How much is your total budget? and as little as possible doesn't work.
2. How tight are your tolerances?
3. How are you mechanical skills?
4. What other tools do you have lying about? Drill press,bench grinder, that sort of thing.
5. Look at Mach3 for $159 Usd or thereabouts. EMC2, Linux based and free.
There are others,just search the net for cnc software.
6.What working envelope are you looking for?
7. Do you have any machining experience, either manual or cnc?

Mike

[Purple_rob]

Good questions,

I would say fair to good with the skills, up until last month I had a mini lathe and completed a few small projects on it. Unfortunately, I sold this with the intention of getting a lathe/milling machine all in one.

I can no longer afford this and thought I would have a go at a small cnc.

For my first attempt I am not looking to machine anything bigger than say 100mm.

I have a few tools left over, bench grinder. Will need another drill press for the frame build.

As for parts and budget, I would like to start with the motors and board + cable & software and looking to spend between 50-100 pounds. Then I could build my machine around this.

Is this unrealistic?

[TOTALLYRC]

Originally Posted by Purple_rob Good questions, I would say fair to good with the skills, up until last month I had a mini lathe and completed a few small projects on it. Unfortunately, I sold this with the intention of getting a lathe/milling machine all in one. I can no longer afford this and thought I would have a go at a small cnc. For my first attempt I am not looking to machine anything bigger than say 100mm. I have a few tools left over, bench grinder. Will need another drill press for the frame build. As for parts and budget, I would like to start with the motors and board + cable & software and looking to spend between 50-100 pounds. Then I could build my machine around this. Is this unrealistic?

100pounds = 200 usd give or take. That is really on the low side of what you need to spend. Pretty much, in my opinion, anything in this price range will not be of much use beyond what this machine can do. If I am wrong somebody please correct me.

Your choice of the low cost controls. Xylotex makes a nice product that would work well for a small machine such as yours. Nema 17 motors should be fine if you are not cutting lots of aluminium. or nema 23 if you get the right price. 2.0 amp and 2-3 mh inductance should work well. 24-30 volt power supply dc. Get low cost motors from eBay or surplus shops.

Xylotex with 3 motors and power supply and contol board $410 usd but I am not sure if they ship to you. You really should get a breakout board also.

Look into other low cost and do it youself drivers. They won't scale up to a larger machine but they will get you started.


If you hang in for a little more money, a Gecko 540 4 axis driver at $299 USD is a great bargain and with some careful shopping for motors and such, you can keep it close to your budget. I looked and 1 usd = .5 pounds give or take.
It will work from the very small to a good midrange machine. It lends itself well to being quick switched from machine to machine because of the connectors and such.

www.geckodrive.com

Don't forget that you will need a computer to run this and not a laptop.

[TOTALLYRC]

For a quick and dirty machine to just get you feet wet. See if you can find a x-y table. They are about $50-$150 in the USA depending on size. Just mount you motors and you have a 2 axis cnc for short money. It will have some back lash. Bolt this to your drill press and you can do the Z axis by hand.
You wont be able to side mill with a drill chuck because of the taper, but it is great for laying out the holes for your new frame or other hole drilling work.

[TONTOEY]

hi I'm new member and this beginer for minicnc