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Tomislav's Homemade CNC Machine

(Original thread started on 04-01-14 by Tomislav Babich)

I have decided to separate this thread from my flight sim build thread.  The body of CNC is assembled (not for long, just to see if everything fits)!

Tomislav 1

 

CNC will soon be disassembled, painted and then assembled for good I hope. Screws don't screw directly in to the MDF so it can be disassembled and assembled without doing any harm to MDF.

 

Motors and drivers are not ordered yet. I am thinking about buying some of these two drivers:

http://www.ebay.com/itm/281221235650?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

http://www.ebay.com/itm/190912663728?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

but am not sure are they good. What do you guys think about them? Also what would be recommended torque for motors (NEMA 23)?

 

I have now narrowed my choice of drivers and steppers to a few eBay listing:

1.  http://www.ebay.com/itm/270997186896?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1 215$

 

I have read nothing but good about longs motor and the price seems decent and even includes PSU. Is this PSU strong enough?

 

2.  http://www.ebay.com/itm/191034864205?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1 198$

 

This package is cheaper than package 1. but I have read good and bad reviews about wantai motor.

 

3.  http://www.ebay.com/itm/180914600475?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1 159,99$ and http://www.ebay.com/itm/CNC-5-Axis-Breakout-Board-interface-for-Stepper-Motor-Driver-Mil-water-pump-/330917635765?pt=LH_DefaultDomain_0&hash=item4d0c3a66b5&afsrc=1 11,99$

 

What would be recommended PSU specs?

 

4.  Motors: http://www.ebay.com/itm/300917444769?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1 89$ or http://www.ebay.com/itm/CNC-kit-3Axis-290OZ-IN-Nema23-stepper-motor-stepping-motor-/321056000156?pt=LH_DefaultDomain_0&hash=item4ac06dc89c&afsrc=1 118.75$

 

Drivers: http://www.ebay.com/itm/281221235650?_trksid=p2055120.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1 79$ or http://www.ebay.com/itm/190912663728?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1 86,98$

 

Two motors and drivers choices but which one is the best and what are the recommended psu specs?

 

Now what is the best option of the above? I personally think 1. but it is also the one with the highest price. Price is a major deciding factor for me so if any of the other cheaper packages is going to do it for me than I would go for it.

 

What do you guys think about above items and which one is the best for my setup?

 

UPDATE:

Yesterday I ordered the option 1. from post #2: http://www.ebay.com/itm/270997186896?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT&afsrc=1

 

X axis of the CNC is assembled! Other two axis are waiting for correct couplers because seller shipped 2 out of 3 couplers in first order in wrong size.

 

Short video of X axis test:

https://youtu.be/Hb3msXOU4NA

 

Now there is only two thing that I need for my CNC:

1. Bits

2. Acrylic

 

I think I will order 1/16 inch and 1/8 inch bits for cutting. Where do you guys order these? What is exact name for this type of bits to search on eBay?

 

For engraving I will order V-bit but I have few thing about it that I am not sure:

1. What angle? Maybe 30 degrees

2. What size of the tip? 0.1 mm or 0.2 mm?

 

This eBay listing seem to me to be priced well: http://www.ebay.com/itm/321320942619?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

I found out that when I wrote bits the item about which I have thought was end mill!

 

Anyway I found this set of 5 pcs of 1/8 inch end mills: http://www.ebay.com/itm/5PCS-1-8-Double-Two-Spiral-Flute-Bits-Solid-Carbide-22mm-End-Mills-/301089889613?pt=LH_DefaultDomain_0&hash=item461a5b1d4d

 

Should I also order some 1/16 inch bits or not?

 

(Posted by Ron Rollo on 07-02-14)

Yes, the two main sizes that I use are 1/16th" and 1/8th". These two sizes will get you started and as you go, you will find that you need different sizes depending on what you design.  What you found on eBay looks perfect.

 

(Posted by Tomislav Babich on 09-20-15)

The CNC is 95% finished. All that is left is the cable management!

 

First of all I made a control box. It houses all the electronics and has connectors for motors, spindle and computer on the back. It has two power switches: one that turns everything on/off and another that turns on/off just the spindle. On the back side there is a fan and on the front side is air intake with filter. Emergency stop switch is connected to breakout card and also shuts spindle down. Also on the back side are three fuses that are connected in parallel with A+ lead of each motor. After, for some unknown reason, one fuse got blown I have discovered that the motor won't stop then but it will move in random direction. Because of that I have ordered more fuse boxes, but this time in-line instead of panel mount, that will be connected in parallel with B+ leads. Those fuses will be added to control box in near future. Unfortunately I only have few pics of the inside:

Tomislav 2

 

After the control box was finished I went on to finish the CNC and here it is:

Tomislav 3

 

As you can see I went with a black-red race car look:

Tomislav 4

 

After assembly was finished I did some test cuts with MDF. As you can see that is Lear 45 RMU outline. You probably see that some line are not straight but that is because of the way the MDF was mounted to machine (brown tape).

 

I have, after a lot of searching, discovered the perfect kind of Perspex to use for my panels. I requested material samples from Perspex and their local distributor was happy to send them to me. When I got them I tried to test cut holes for my switches. In third trial I have gotten the hole to be square with straight edges! At the bottom you can see the switch holes. At the top you can see some engraving I have tried. I haven't had much time to play with engraving yet so that is why it looks how it looks.

 

But the switch doesn't fit to the square hole because the corners are not square. It seems to me that I will need to order some smaller bits. I have 1/8 inch bits. Is it possible to cut corners so that switch fits with those bits or do I need 1/16 inch bits?

 

If you think I was able to start cutting without melting plastic you are wrong. I had some plastic from local hobby store. On the label it showed that it can be cut and drilled but no matter what I did it melted. After that I ordered those Perspex sample and they are great. But I was lucky enough to save all my bit, I have managed to clean all of them from melted plastic.

 

That Perspex is from their Spectrum LED series. It is made specially for applications that require back lighting with LED's, perfect for my panels.

 

(Posted by Ron Rollo on 09-20-15)

Wow, looks like you are well on your way with your CNC. By the way guys, Tomislav is a teenager, very impressive! I wish I had got into this sort of stuff at your young age.

 

I might have said this earlier, but you will want to use cast plastic. Extruded plastic will melt and nothing will go right. CAST plastic only!