They get all of our money!
Originally Posted by BrokenRotor
I was reading an earlier post in this thread. It was wondering if you needed a VFD (variable frequency drive) on a mill. The question was answered but just in general terms. To be a little more specific,this is just a way to control the speed of the spindle motor (or any motor). Depending on which type of motor you have (AC or DC) will determine the method of control. AC will use a VFD where you could run a 3 phase AC motor on single phase for example. A DC motor runs via an inverter.
1. I would look at Vectric Cut 2D VERY easy CAM program to run. CamBam can be a little overwhelming at first(at least for me). You can do very simple drawings in it and if you get creative it can handle most all you will need.
2. Yea Mach3 for control functions. What I really like about Mach are the Lathe wizards that will handle most everything for turning right at the machine.
3. I personally use Alibre CAD for more complex drawings they offer a cheap version for less then $200. You can probably put this off and just play with the CAM software till comfortable and need more options.
ZeroFighter....Been reading through your build, very nice. I notice though that your mounting of the Y ballscrew is to a table that is much bigger than what I have on my machine. Can you say more on that? I'm thinking I need to get that bigger table. Maybe I missed it but I don't think this was covered in Fanblade's thread either...Bruce
Hey Bruce,
Do you have the Grizzly version of the machine? I know there are a few versions out there that are all slightly different but I believe are all made in the same factory. I picked up the grizzly one because it has the longest travel out of the bench models I've found. Not sure if that helps, but worst case, you might be able to order that one part from Grizzly and get a bit more travel...
Carl
Carl...Yea, mine is a Grizzly, model 4015Z; different than yours but looks almost the same. I'l see if I can just order the table off of your model - G9729. ..anxious to see your next update...Bruce
Good luck Bruce, and link us to your machine if you do the conversion.
I've made some things on my machine aside from our usual suspension parts (mostly adjustable length 7075 with rod ends).
These are hood/trunk pins made from 7075 as well, I broke the cheap chinese aluminum ones I had bought, they were garbage.
Also needed to make 2 master cylinder adapters to fit the reservoirs, tried to make them by drawing the contour I needed but was too complex, just did it with the wizards instead. Made 2 and screwed them up, then made 2 good ones. Did the threads with a die, once my speed sensor is working I can get much nicer threads with the CNC.
These are a couple of the parts my friend and I produce for Mazda RX-7's.
Some test turning
Machining a door handle support end:
And one more. Really need to fix the spindle. Vibrates like crazy.
I made some improvements to the mill head, and have a plan to re-do the Z axis bracketry. Right now it's 4 pieces, and I plan on changed it to 2 pieces.
That will be the bottom part, 3/4" 6061, will be much stiffer than what I have now. Right now when the spindle heats up, it doesn't travel too smooth, this will help somewhat. Will also do the other part of the Z work.
Managed to make some cool stuff with the lathe:
It's a mold for 50mm carbon fiber intake velocity stacks.
I have a few questions on things I want to improve.
The mill still has some vibration. I want to fill the head stock with epoxy/substrate, think this is useful to do? It's completely hollow and the mill head hangs out pretty far from the tower.
Belt driven X/Y axis? Would it be wise for me to go away from direct drive, and move to belt driven for the stepper motors? I would get more torque, and some finer step controls, although I'm not sure that is necessary.
Thoughts?
Thanks,
I haven't done anything with direct drive but have used the belt drive (McMaster-carr sells the belts and the gears). I'm not sure there is a clear winner but I think it might be easier with belts to revert to manual operation (just cut the power supply and use the original hand cranks) and also in the event of a head crash the belt will slip and act a bit like a fuse. One problem though is that if chips or even dust build-up finds its way into the splines of the cog, it affects the quality of cutting. So a guard or something is needed.
Zero, What is your micro stepping value set up in your controller? You might be able to use a finer resolution.
Bruce, The idea of manual machining on a CNC machine is a waste of time. Everybody thinks this is important including me on their first machine or so, until they learn to use MDI, an MPG or a Shuttle Pro. You could use dual shaft steppers and merely install hand wheels and accomplish the same thing. If you use ball screws in your transformation they wont offer enough resistance for good manual machining.
In regards to the belt slipping during a crash or running into a physical limit of some kind is that the stepper will stall first most likely.
Fastest1, not too concerned with resolution, more so the extra torque I'd see by the gearing I could use with the belts, is it worth it?
Right now my issues seem to be with stiffness, of my Z lathe axis, Y, mill axis, as well as the gib adjustment to remove any clunking/vibration I see when milling. The table itself is hard, like you found, to get the gibs adjusted just so, no binding, but tight enough to not clunk or move when milling.
Did you ever get your mill part of your 9729 finished?
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Sorry, that last one was directed to FannBlade, not you!
Zero, most of my machines are direct drive.
I do have 2 machines that are mechanically geared down to almost slow speeds. 1 of those is actually being refitted with pulleys and belts now. I plan on changing ratio for more speed. Though I will be running much more modern electronics and steppers, larger too. So far all of my machines have been able to easily overload the tool or spindle, causing breakage of the part or tool. Even on my Sherlines. Torque really doesn't seem to be an issue in my experience.
Gib adjustment and getting it right changes everything.
A lazy man does it twice.
Ok, that's sort of what I was looking for. Whether direct drive was the way to go for me. I have 400oz steppers on there which should be enough. Mostly machine aluminum anyways.
Sent from my SGH-I337M using Tapatalk
Belts make no sense with steppers - a better motor will cost about the same, or likely less, than all the extra belts, pulleys, bearings and housings. Belts are typically used on drives to change the speed range. On servo machines, they're used because most servo motors are capable of RPMs far beyond what can be used in a direct drive setup. So, a belt drive is added to reduce the speed, and allow a smaller motor to be used. Steppers have max torque at low RPM, where you need it, so belt reducers just aren't needed, when it's so cheap and easy to simply fit a larger motor.
Regards,
Ray L.
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