I have just startet reading about this, but for the few things I have done with my machine so far I've used the lower value of this chart and it has been ok:
http://pdsspindles.com/admin/modules...20(Inches).jpg
I have just startet reading about this, but for the few things I have done with my machine so far I've used the lower value of this chart and it has been ok:
http://pdsspindles.com/admin/modules...20(Inches).jpg
.003-.005" for 1/8" and .005-.007" for 1/4" in aluminum is a task for a toolroom mill, let a lone a home-made CNC. Most manufacturers of the tools I use have half those chiploads recommended. You'd need a very powerful spindle (PDS sells up to 40HP) and a very rigid machine...
You are right, I can't imagine how the so-called speed control would keep up with these chip loads.
I tested a lot in the last week and for 1/8 Chinese cutters, I'm using 0.0015 to 0.002. Less than that will burn the cutter. For 3/16, it is 0.002-0.003. All at 0.015-0.020 DOC With these numbers, the spindle can handle it without too big rpm fluctuations.
For wood, I try to follow what the manufacturer recommendation but if I feel that my machine might flex too much, I take shallower cuts.
I'm waiting for Amana cutters to mill alu and will apply the same rule except that I think I will take shallow DOC right off the bat and see how the machine reacts.
When you put it that way it totally makes sence Thanks.
Sorry Biggs for a little off topic here.
No big changes lately, not even using my machine as much as I would like, but something was bugging me.
I had problems with my limit switches sometimes tripping with a false alarm, especially when doing solid surface.
So I decided to start my "Controller box 2.0" that I postponed for too long now. I have all parts to use 24v for inputs (Limits, holds, E-Stop, etc)
I found 24v to 5v 8 and 4 bits optocouplers boards. This works well with the proximity sensors that I plan to use for homing as well as with the standard mechanical limit switch that I will use for limits.
Attachment 368206
I have plenty of old server cases at work that would have enough space and it have a nice PS to powers the 5v controller and 12v cooling fans.
When you switch to 24v logic all the false fails will end
Russ
Yeah, that's what I'm hoping!
I have a small DIN 24v 0.63A power supply and I'm wondering if it will be enough to power the 8 inputs I will need: 3 proximity sensors, 5 standard switches (3 limits, Start and Hold)
All will be configured NC.
Edit: That's the PS I have: DR-15-24 Mean Well | Mouser Canada
The proximity sensors typically draw around 100mA or less, check your specs, but I would think that little supply will be all you really need.
Russ
I found an old workstation computer case that I installed a 1/16 steel sheet in it.
The TB6600 drives for X1, X2 and Z have enough space to accept bigger drives. I'm aiming for AM882 but a DM556 would be enough for my needs. It all depend on what I find on Ebay.
The din rail has been installed and I started to put the main relay, AC terminal blocks and the logic 24v PS that I hope will have enough amperage. I left enough space to accommodate a bigger PC if I need it.
GRBL controllers on Arduino Nano are tiny, even with screw shield, but I left enough space to put a bigger one. Probably an UC300 if I decide that GRBL doesn't suits my needs anymore.
Between the Arduino and the drives I will put a second DIN rail to mount the 24v to 5v optoisolator.
I might be able to put my SuperPID in the case but will likely put in in a case outside; that might helps with noise issues.
Quick question about the main relay.
I plan to use it to power the stepper 48v PS (480W), the 12v chassis fan PS (maybe 50w), 24v logic PS (25w-50w ?)
So around 700W max but likely less than that as the stepper won't use the whole 480W and the super PID will have its own circuit.
Is the 10A realy enough? Do I need something bigger?
I've seen bigger build uses contactors but my understanding is that a contactor act like a relay but at higher current. Am I missing something?
Thanks
120VAC at 10amps = 1200 watts. I'd say your good.
Dumb question - what kind of linear rails are those?
X and Y are 15mm Chinese profile rails from BST automation and the Z are 12mm Chinese too
Back from vacation and got the time to continue my controller box.
It's a bit crowdy in there but at least every connection have screw terminal, ferules on every wires, the logic is 24v and I even been able to fit an volt/amp meter to the mix.
I even got help to crimp the ferules on the wires.
The most important thing now is that the thing is documented!! I made a wiring diagram using TinyCad and following this, I had no errors the first time I fired it up!
It is 90% done now. The only missing parts are the SuperPID and limit switch.
The 15mm are HGR15 as the price is about the same as the mgn but it uses M4 bolts instead of M3.
The mgn12 is "ok" for the Z axis but imbworking most exclusively with wood. The M3 bolts it uses are a real PITA to work with.
If I find affordables 15mm rails I will upgrade the Z.
I got a small contract to do body lightened braces for two late model race cars using 6061-T5 1x1x0.125 angles.
I built a jig out of plywood to be able to machine parts at a time. The angle is held with a clamp that makes the lenght of of the jig and four M6 bolts hold it in place. I've machined the brace with positionning holes so the part are always within 0.015.
I've sealed the jig with epoxy cause I thought I needed some coolant but I cut dry without problems now using a cheap chinese 2 flutes 6mm cutter. The 2 flutes cutter seems to be the one with the best removal rate vs heat. I run the machine at 50 IPM (1270mm/min), 12.5k RPM and 0.040 DOC (1mm).
In the tests I did before, I wasn't able to have a DOC more than 0.015 - 0.020 and I thought that I reached out the rigidity of my machine but with the new jig and better clamping, it seems that the limit was the clamping, not the machine. I ordered 30deg helix 2 flutes carbide cutter to test the max DOC my machine can do with proper tooling.
Edit: The SuperPID also seems to help with heat a lot by keeping the RPM steady.
This is the end result: 50 feets of lightened braces. I think I will produce some in advance as stock car pilots have a tendency to break this kind of parts. LOL
Edit2: I just looked at the last picture... My workbench needs a serious cleanup!!
Nice!!
That's a really nice finish you achieved on those cut outs. Good work.