Awsome machine! Just wondering what usb controller you used with Mach3?. Cheers
Sent from my LG-H870DS using Tapatalk
All air cylinders eventually leak to some degree or another. Your best bet here would be to have an airline ran to you tank to keep it topped off. As you note the air cylinder itself doesn't have to be too big in diameter to effectively counter balance a slide. However you still will have a significant pressure increase in your reservoir as the piston is pushed against the construing air. Here is where a pressure regulator that can handle reverse flow comes in handy.
Awsome machine! Just wondering what usb controller you used with Mach3?. Cheers
Sent from my LG-H870DS using Tapatalk
Outstanding build! I like that you used such a thick cross-section in the gantry.
Did you weigh the gantry before and after the EG fill?
bob
Nice, im currently running 2000mm/m^2 acceleration, should be able to go higher with better gearing on Thor.
Very interested in this NT30 spindle too. This is the closest thing I could find, any idea if this could be 'forced' to work the same way? Is it even the same thing?
https://www.chronos.ltd.uk/acatalog/info_VRANT30.html
No ATC on yours, how are the tools held in place?
Absolutely beautiful build, seems to do an amazing job on aluminum. You can certainly be proud of this machine. Very nice job.
Russ
I absolutely love this! I found it on youtube, it made my day and I really cant wait to upgrade my machine now!
My hat is off to you on this build!!! Watching the video, your machine certainly performs as well or better than some of the industrial machines I have seen over the years. Brilliant job!
Chris D
The nut on a 10mm pitch Chinese ballscrew is much longer than it is on a 5mm. Not sure how this effects the force on the wall of the screw. Regardless, you are using servos that are capable of higher speeds compared to steppers, and whip doesn't seem to be an issue for you, so I have nothing but praise for you and your design decisions on this build. Truly an awesome build sir. I come back every now and then to look at how you've done some things. Certainly one of the best builds as far as quality and performance go.
I just have one question for you. Where did you buy your ballscrews? I've been reading some horror stories about Chinese ballscrews, but I also know that some of the Chinese stuff is great quality, you just have to pick the right supplier. Looks like the ones you bought are performing well. What are your opinions?
Awesome build! I would love to build something similar to this. How much has the project cost you if you don't mind my asking.
Glad you like it. Since I got it in motion, I made a lot of parts for some other machine, and it works great. I have also bought BT30 ATC spindle for this machine, I will post here when I upgrade it. Yes, you are right, quality of Chinese stuff is very different. I am lucky I have a great forwarder there, so he finds good quality for me. Ive attached some pictures, This is woodworking machine I am making for a friend of mine. All of the milled aluminium parts I made on my smaller machine.
You're clearly a CNC genius!
Is that 4 pneumatic cylinders for the counterbalance? Where is your reservoir, are you routing your tube throughout the entire cable chain?
I'd be very interested in hearing more about how you are accomplishing the work holding. I am aware that some machines like Biesse do this, I haven't seen it on a DIY build until now, I have been thinking of something similar on my machine where I will have a 4th axis under the table, was thinking removable table, but sliding table supports may be better. That's one thing I haven't finalized.
Thank you. Ive made some pictures for you. As you can see, small aluminium "brakes" are mounted on each side of alu profile. When you grab handle and push it down, you will release two pneumatic cilinders that will push into aluminium brakes and hold alu profile. So when cilinders arent pushing, you can move profiles arround.
On profiles, there will be vacuum pods, 3 pieces on each profile. I will make pictures when Im finished. Should be next week.. About counter balance cylinder, it is one cylinder, you can see it sticking in air, longest one. For air reservoir, I just drilled two holes in cross square profile. One for direct connection with cylinder, and one for input from regulator. Welds are air tight, so there is no leaking. Voume is approx 15L. I use sepperate pressure regulator, and have it constantly connected to this "reservoir", so if there are any small leaks, it constantly fills it up. This sistem works great, and Z ballscrew should last very long, as whole Z axis now practically floats in air. Two double rod cylinders you were looking at are for lifting up and down vacum suction system.
OK, that's just awesome.
I don't claim to understand all what you've done, but awesome it is.
So those clamps slide in the T-slot and are hooked up to pneumatic cylinders. I had to look at it a few times, then I understood.
Is this gantry made from steel? It's painted so I can't tell? Are you going to fill this one with epoxy granite?
The machine that I'm making is from steel tube, but it bolts together in many places. My Z axis is also a Square steel tube with a 1/2" plate welded into the nose of it that the spindle will flange mount to. This is stronger than a flat plate Z axis, unfortunately because of the flange mount on my spindle, which attaches at the nose of the spindle, the spindle body doesn't add any strength to the Z. The problem I am considering is the steel tube will ring like a bell, I can't fill the tube as the spindle will be in it, so I am thinking about bolting some plastic channels to the outside and filling them with some kind of dampening material.
Actually, I have even been thinking about gluing some thick HDPE strips to the outside of the tube, simply to change the resonant frequency.
What are your thoughts on this?
Nice build! I wish I would have found this thread before I started my build. Lots of great info and inspiration. I am also building a machine to mill aluminum with a similar footprint and spindle weight.
I am dealing with a similar balancing issue. I bought a 35lb gas spring to balance a 35lb spindle and to take the weight off the nut on the Z-axis. Now that it arrived, I think I made a mistake. Gas springs seem to increase in force as the stroke increases. I.e. They don't provide even weight balancing as you move the spindle up and down the Z axis. It would only provide 35lb of balancing force at the bottom of the axis and provide zero balancing at the top (when the spring is in it's rest position)...
I am wondering if a simple balancing weight might do the job better (like the lat pulldown at the gym). This way, if I used a 35lb weight, it would provide 35lb of balancing at any point on the z-axis....
Please can you explain how your regulated air cylinder solution works in this respect? I can see how a regulator would allow you to maintain consistent pressure going into the cylinder but I don't understand how it would prevent the pressure increasing as the cylinder compresses the air inside on the return stroke?
Or am I worrying too much about maintaining even balancing pressure / weight?
There are gas struts, which are sealed units with an internal reservoir. These are the kinds of things you will see on the hatch for your minivan. Is this what you bought? If so, it doesn't have zero at the top. Yes, gas struts do not maintain a constant force for the whole stroke, but it isn't 35 to 0. perhaps 29 to 40. Which would still balance really well except for the dampening aspect that most gas struts have. That's why I chose to go with pneumatic cylinders with a reservoir, commonly referred to as a gas spring by many.
In reality both things are "springs" that use gas. If what you bought was a pneumatic cylinder and you simply plugged one end, you would have a huge amount of force at the bottom, and zero at the top, if the cylinder could extend all the way to the bottom, which of course it can't, then theoretically you would have infinite force at the bottom and zero at the top. You need to use an air reservoir where P1V1 = P2V2. The larger the pressure and the larger the reservoir, the less force difference you will have at top and bottom of the stroke. The area of the bore, or the area of the bore minus the area of the rod (depending on the pneumatic cylinder's orientation), determines how much force is exerted by the spring for a given pressure. Rodless cylinders are another option for this.
linux_fan understands how these work better than I do, I am going for a closed system that I only occasionally have to top up (fingers crossed), whereas his is fully regulated.
That only works on something like a mill where you have a moving XY table and a stationary Z column.
Very nice build.
The one I bought is a gas strut as you described. I got the LMS one that is used on some of their smaller mills as it had the right level of force for my spindle weight.
I am less worried about this since my last post though. I realized that I don't really need it to provide a consistent 35lb counter balance everywhere on the axis. I just need it to lift enough weight to prevent it going over the rated weight for my Z axis ball nuts.
I also just upgraded my Z axis screws and the new double nut holds a lot more than the 25lb limit on my deralin lead screw nuts.
I can see that it would be harder to design a weighted counter-balance on a moving spindle machine. It's probably not impossible though. You would just need the counter weight mechanism to travel along the axis with the spindle. It would probably look messy and maybe require a different x-axis design so maybe it's just not worth it.
I would definitely like to avoid using any compressed air products in my build if possible. I use a lot of high pressure air gear for my pre-charged air rifles so I know from experience that they can be a recipe for problems. Valves can leak and any tank or cylinder failures can be very dangerous.
You can see how everything works on video now:
I am so happy to see such a nice and clean build , i am wondering how u make acurate straight place for rails ?
Do u machine them or use epoxy fill ?
Have a good time .
Only 3 parts for such a build ?! :-P
Man this is a master piece I'd want to know everything about
Envoyé de mon A0001 en utilisant Tapatalk