Thanks for the reply, I will give it a go !

 

Glad to help. Also, you can measure the deflection on your Z by gently pulling the top of the router, and pushing on the collet towards the back of the machine. If you see the spindle or router move relative to the Z carriage plate, you'll need to stiffen it up. But, how stiff it needs to be depends on your cutting speed (and feed). Look at the Maslow CNC: it just hangs on some chains and does just fine.

Good luck - post a pic when you cut something!

 

One thing that didn't occur to me earlier: on the Minimill, there are two or three screws going into the back of the router mount, through the Z plate, in addition to the angle connectors. I'm not sure if it's done that way on your machine or not, but that could account for the difference.

 

Fun and easy modification:

I found that flipping the connectors between the Y and Z axes around so that the braces (and the cast connectors) point backward, and shifting the Y back to compensate, gives about another inch of usable cutting area on each side of your work piece, basically adding 1.5"-1.75" to the usable Y travel.

You lose a little travel in the front, but it looks like I still have plenty of room for getting parts out.

YMMV. (Or should it be Your Y May Vary?)

 

Slowly moving along. Watching heaps of YouTube and researching a lot on google to make sure I’m wiring it right

 

Yeah I play a little with RC cars... this one has run 100mph. Need the CNC to make a few custom parts to make it go faster.

 

So what happens when the driver is dead on arrival???

I have tested the wiring with he other drivers and all the wiring is correct. But simply not lighting up when the power supply puts power to it.

 

Thanks Gary.
As mentioned I did test it with the other working axis. Just keen to keep the ball rolling on this project! It’s too much fun to have to wait for parts.

 

Hi! I'm looking to lower the operating cost of my soon to be built minimill, is there any suggestions for cheap tooling and maybe free CAM software? I have no qualms about learning to write GCODE but I was wondering if there are any free resources? Thanks!

 

Hi all, I would like to increase the work area of my MiniMill. I am assuming that the easiest way is the replace the X-axis C-beam with a larger one, say 500mm.
My concern is with the gantry plate: currently it fits the working area of the machine. Won't I lose stability/rigidity if I double X but stay with the current gantry plate?

 

Have you tried fusion 360?

 

Hello, I have been doing a lot of research on desktop CNC machines and came across this MiniMill here on OpenBuilds tonight. I'm looking for something that I can mainly use for engraving artwork onto hand made knives. The knives are made with O1 tool steel but then powder coated black. I would be mainly cutting through the powder coating. I'm sure this machine can handle that part, but could it then just lightly score (engrave) the steel? I would be using a very small precision tool (bit) and I have no problem with cutting very slowly. I'm also interested in using the MiniMill for cutting prototype aluminum parts for folding knives as well as a completely different project I have for an HPC cooling chassis that I was awarded the patent for last year. My main purpose for the MiniMill would be engraving the knives though so I'm hoping that someone here on the forums can help shed some light on that subject before I move forward and purchase the bundled MiniMill on the OpenBuilds store. Also, wondering roughly how long it takes to have a MiniMill delivered once it is ordered. Are they already built and ship out, or built-to-order? I'm attaching a photo of a recent knife that I just made for a customer to show the type of artwork I will be engraving into the metal. This artwork was done with more of stencil and the quality of the graphics is not exactly what I was hoping for. The engraving into the surface of the steel will be much better and last longer. Thanks so much in advance for the help! ***Lastly if there might be a more well suited desktop CNC machine available on OpenBuilds that I did not notice then please let me know***

 

The work area of the MiniMill is pretty small (less than 5" x 5"). I don't think it will do a blade that long. You might want to consider the C-beam Machine: OpenBuilds C-Beam Machine

BTW, shipping is very quick!

 

Thanks for the reply. I was also looking at the C-beam machine as well for the larger size. My bigger question though is if it can lightly score stainless steel?

 

I'm also trying to decide if I should go with the MiniMill or the C-Beam machine. It appears to me that using two X and two Y rails, and bracing the gantry support with plates or diagonal supports would add a lot of rigidity to the machine. The MiniMill looks like it would have a lot of flex at the plate that joins the X and Y axis. Am I correct? I will be making thick aluminum plates, and some small aluminum parts for drones and RC cars. I am a programmer and very good with electronics, so the control side is not an issue. Some day I want to make an aluminum v8 at 1/5 to 1/7 scale. Should I just get a small vertical mill now and convert it to CNC instead of the C-Beam machine or MiniMill? I'm also looking at the SwissMak turn-mill on kickstarter, but it's much more expensive of course. I'm not sure I can really justify the cost for what will basically be another toy for me.

 

I also am still waiting to hear back from the experienced users here if the minimill or c-beam can score hardened tool steel. I want to engrave the powder coating on knives I'm making and just slightly score the steel for artwork and lettering on the blades. Can anyone confirm if this is feasible so I can make an informed purchase. I understand that I can't cut hardened tool steel at all but I'm hoping to just ever so slightly engrave it. Has anyone done anything like this? Thanks for the help!

 

To help with some of the questions above. I have just bought the mini mill and just finished the assembly and wiring. It’s a pretty cool machine. I got the mini mill for transportation, I want to show our cam software for windows and doors talking to a CNC. In regards to rigidity it looks pretty good and there are videos of the mini mill machining pretty solid Aluminum.

The are many factors that go into machining, the cutters, speed and feed rates, depth of cut, type of cut, rigidity of the machine, torque of the stepper motors, the motor drivers and micro steps and the speed and power of the spindle.

For engraving the mini mill should work fine and the load will not be great but you would have to look at a hi rpm spindle due the the speeds and feeds you need for that fine work.

The C beam would have extra rigidity due to the design and I think the smoothie board and run two motors for one axis possible two so you could double your motors on the x and y, but you will need to look into that some more.

These are just my own opinions on limited experience on these machines.

One thing I can say is that I have enjoyed building and learning about building the machine!

 

Printed a few holders for the micro switches and clamp to hold down a cheap aluminium vice.

 

Ok so i have the machine up and running but having a mental block what it comes to the work space. i have set the machine to home to max (rear right) i have set the machine position to the max travel. then i set G45 to the top right of my work piece but as you can see on the pc (in the image below) that the work is not in the machines working area. I'm using BCNC and the axis seam to all move in the right direction. i press X+ and it moves to the right and y+ it moves to the rear.

Should i be thinking the opposite? as the work piece is moving not the spindle?

thanks

 

When you command a move in the X+ direction, the gantry should move to the left, in the Y+ direction the gantry should move toward you. +/- are from the tool's perspective.
Typically "machine zero" is with all axes positioned at the maximum + direction (Z all the way up, gantry all the way forward and to the left. "Work zero", on the other hand, is usually at the forward (toward you), left corner of the work piece.

 

Sounds about right. I need to think in the tool perspective not the work piece...

That’s not half confusing...

Most of the machines I worked on the tool moved and the work was fixed. I did play on a Hartford for a while but it had a jog wheel so it was a bit different.

 

Making cuts.....

Need to do some work on the vice, but it’s all starting to come together.

 

What is the most aggressive anyone has cut aluminum on the mini mill so far? I'm using a 1hp router and have been able to run a 1/8 kyrocera end mill at 550mm/min at .5mm doc pretty well. I'm afraid of going much faster, but I have a project that will take really long at that rate. Has anyone found better recipes with adaptives or something that allows faster pocketing?

 

I’v been making 1mm deep cuts on my mini mill at about 300mm/min.