The cut depth was set to 0.0762mm same as @The Dude suggested for acrylic. Since it was my first real cut wasn't sure what to expect so I set it low. I was also using the same feed settings of 200 mm/min. What is the worst that can happen if I push the machine too fast and or too deep with depth of cuts for the material I am using? I looked in the speeds and feed charts but didn't see anything listed for wood products or MDF.
'Pushing' the machine can have quite a few results. The bit can break, you can miss steps, cuts will be imprecise (especially when changing direction), spindle will stall and more.
@Chris Allen and @JustinTime Just curious how you guys attached your Cable Drag Chain's to your machines. Is it resting on something? Got any pictures or skp files? Mounted to the side somehow? etc. I snapped a wire loose today, I should have ordered these earlier. Yep you were right!
Thanks @JustinTime gives me a good idea of how I will hook it up to the machine I have here. Thanks for giving me a preview of what I'll be getting myself into. Much appreciated.
Just a quick one for anyone mounting a dremel tool. I found a better way to mount it and lock it down super tight. Home Depot or Lowes carries Conduit Pipe Straps 1 1/2 inch clamp worked wonderfully on my machine. http://www.homedepot.com/p/Unbrande...be-EMT-2-Hole-Straps-25-Pack-61615B/202241092 you can get them in a single package of 2. The gantry will break before that tool moves now, its not budging moving anymore. Keep in mind I have 20x80 where you mount the tool and it works well for me. For those of you using 20x40 take care you may need to construct some sort of adapter plate so it will fit nicely. Cheers
@Ceiling Cat, Yes, makes sense ... I already got some of these to use when I upgrade my Routy to an Ox ... it is the way recommended for that build. I need to work a bit more on using Routy to accurately machine plates for OX, when I get back home in a few weeks from Beijing. Been recearching best way to build good bet for this set-up ... considering 80/20 10 series so I can use 1/4" bolts, clamps, etc.
Haha, yeah with wood try 800mm/min and cut depth of 1mm. Acrylic is "special" like aluminum, brass, etc. You could try 0.5mm for really clean edges. I think I've run pine through mine at 1400mm/min with ratty edges. One time I had the axis reversed and so it plunged the bit into the wood at top speed(1500mm/min) to a depth of about 25cm. Scared the bajeesus out of me but no harm befell my routy.
Is 1500mm/min the top speed of routy? Only thing I have tried is around 200 thus far. I want to run it now but machine is down for repairs presently . I burnt up a stepper apparently. Not sure how it happened but one of them on the y axis doesn't even spin anymore, just kind makes high pitch grunting noise. I ordered 4 new Nema 17's all 1.8 degree steps for better holding torque. Not using second hand steppers this time around. Do any of you leave the plastic on when cutting your acrylic or do you peel it off? I've been peeling it off but wondering if it would help to keep it from getting scratched if I leave it on.
My motors stall at anything faster than 1500. It all depends on your controller board+motors. I don't have plastic on my acrylic but it doesn't matter either way.
hey all kinda new to the whole cnc thing. but have a lot of experience with 3dprinters. i have just finished the build of routy and have a question. am i able to use RAMPS to run this? id really like to use elecronics i have/know. if so how would i o about this. and finally im having difficulty finding an appropriote router am currently looking at the kress 1050 but think it might be a little heavy. thanks mevo
3D printers and CNC machines have identical components with the exception of the router/print head. If you can run GCode you can do CNC. The best router, by far, is the 890KV OX spindle plus it costs less than any others. I think you need a drill press to make it.
so plan is strap dremel and RAMPS to bootstrap/routy, mill plates, build new spindle? or am i missing a step? cheers mevo
No that should work. I don't have a dremel so I used the 890kv motor to make the 890kv spindle. Lots of people just use dremels but they have bad runout. Also, if you are just beginning, start with milling foam, then soft wood, then something hard but cheap... like acrylic. Then try the aluminum. One glitch in your code or one loose wire or one bad chip and you'll have a very expensive project on your hand with all the defective parts, broken bits, etc.
do i need any specific firmware for ramps in order to connect to a cnc controller, or do i just use printer software with gcode i gleem from hsmworks?
I don't know. I think everything is done in GCode. There's a program called Skeinforge that is used to do both CNC and 3D printing gcode generation. The difference is very subtle... in CAD we call it a pocket vs a pad. In CNC we start at the top, in 3D printing we start at the bottom. The firmware will not need a heater for CNC so that code may have to be reworked. I'd look around for a CNC firmware for RAMPS https://capolight.wordpress.com/2010/12/05/cnc-milling-with-ramps/ My system uses LinuxCNC and all I have to do is throw in some new GCODE and it can run a 3D printhead. Some other code and it's a laser cutter. Some other code it's a drag-knife... Some other code and it's a pen-plotter.
Great info Dude I also would like to throw out there a good one to use with the Ramps board is the control software repetier host (free) http://www.repetier.com/documentation/repetier-host/ I use it exclusively for 3D printing and have not tried this feature, but from the drop down in machine types there is a cnc router option. My guess it this would be a good place to give routing with the Ramps board a go. Hope this helps.
I'll second that. I'm working with acrylic now and if you plan to cut it with a dremel then plan for it to melt a little around the bit. One tip when cutting acrylic. Do not try and cool it down like you would when cutting metal by using some sort of lubricant. Its a god aweful mess and your acrylic is going to start cracking and chipping like mad. Its better to just melt your way through it and clean up the burrs later. NEVER use water with acrylic! Lesson learned the hard way. This is good advice. I just screwed up half a sheet of acrylic. Jog your machine about before cutting anything no mater how good you think your connections are. If your like me and don't have a workshop and have to move your machine around a lot you will probably want to get some cable drag chains. When the machine is in transit wires tend to come loose. Especially if your using solid hook up wire. Use stranded if you can, holds better in the terminal blocks. Pay particular attention to your Y axis with this machine. Since your driving 2 steppers from a single driver if just one of the 8 wires is not making a good connection your cut will be ruined.
Look into getting an upcut O bit for the acrylic cutting and check speeds and feeds. Its important that the 'chips' are removed from the cutting quickly. So that they do not sit and melt back on themselves. http://www.onsrud.com/plusdocs/Doc/index.html?model.code=SuperO
I will give it a shot. The bit I was using was a general metric titanium bit. I can post a video of the fail later so you can see what happened, basically after water was put on the acrylic, chips started orbiting (yes orbiting is the right word) around the bit. These upcut O bits are a 'bit' expensive but if it keeps me from having to buy another 20 dollar sheet of acrylic then I guess its worth the investment. Just wondering if I should go with the 2mm bit 65-000M or the 1/8" bit 65-010. Any suggestions? I'm using a dremel.
I cut acrylic the same as I cut aluminum using my used aluminum cutting bits and a mixture of water and dish soap, 20 ipm 1/64 passes
Be sure to be careful if using MDF spoil boards as they will swell, the trick I find works best is a spray bottle misting the acrylic, if the mix is right it foams up contains the chips and keeps the bit clean.
How about making your own cable guides with your router? I've never had water causing cracking in acrylic, but alcohol will do it for sure. DO NOT plan to have the bit melting the plastic, the bit must cut it. If it is not cutting you are running something too fast/deep and not allowing the chips to clear. Remember the heat is supposed to depart with the chips. I got very good cuts in 6mm acrylic, 6mm 2 flute carbide bit (for wood), at 700mm/min feed at 15000 rpm (slowed the spindle down from 30000!), depth of each pass was 0.9mm. If you are planning to cut a lot of acrylic then please buy some real 'designed for plastic' bits, they really are very good. Low flute counts must be used in plastics to clear the chips. I also recommend using one of the many online feed rate calculators to accurately set your feed rates from rpm, tooth count, and chip load per tooth (which will be recommended by the cutter maker for different materials). Solid hook up wire? don't do that, it will fatigue crack. Anything that moves must use stranded wires, please.
ok. i have a really dumb question. how do i wire a dremel to this? think i have some reading to do, anyone point me in the right direction? yhnx mevo
I used electrical conduit pipe straps to hold mine on the z axis. It is the most rigid I have found thus far. See page 17 of forum for the post.
Yeah I just cut aluminum with my settings I used on acrylic. 20ipm is a little fast for me because I haven't completed the spindle yet but I would think 400mm/min would work well if I had the spindle done. Anyway I just cut the acrylic with no lube. The aluminum I used 80weight oil and it was a mess but the bit is still sharp
Please do not guess at feed rates, this is science not art Feed rate calculators are all over the web, use them. an example, http://www.whitneytool.com/calculatorSpeedFeed.html that includes surface speeds for various materials as reference. from the material and bit size you get RPM, and from RPM and tooth count you get feed speed. Please do not use oil for cutting. Oil is too good at lubricating and causes high side forces, for cutting you need something to lubricate only a little and then allow cutting, while carrying away heat. On aluminum use kerosene or rub on candle wax, commerical high speed CNC uses ethanol spray (youtube Datron cnc) with suitable ventilation. If you really want nice cutting, buy a commerical 'made for aluminum' cutting compound, expensive but very good. and as with any routing, keep the chips clear, you do not want to recut the chips, it causes extra tool wear, and poor surface finish because the chips gets pushed into the surface making a dent before the cutter cuts it again.