I have a 3/4" flat bit in now. But when I just draw a 31x31 rectangle in easel and say to do a 1/32" cut, it say it will take 32 hours? I tried to start a cut, and it seemed to cut down a rectangle in the middle of the board, and then proceed to start working it’s way out, but only seemed to take less than a millimeter more material each pass. Is there a way other than learning to write gcode manually that I can plane down my board in a reasonable amount of time?
I don’t recommend this but you could try removing the bulk of the material by running the wasteboard through a planer. I would run a scrap piece of MDF through first just to make sure it will work. Then you could go over the last layer with the end mill. Be warned though: this approach will most likely destroy a few planer blades, create a large amount of sawdust, and may not make the smoothest of cuts
that is a terrible suggestion…
i mean it really is on so many levels.
Just buy a surface trimming bit with a decent diameter, and set stepover to 45%.
I don’t use easel though so I am not familiar with its functionality, but I would assume something basic as this should be supported.
The main fault in this method would be that the waste board would still not be leveled to the machine. The way to do that is to use the machine to do it. I leveled mine the best I could and then use a sacrificial waste board on top leveled with the spindle. It works well enough.
Thats why I recommended leveling the waste board on the CNC during the last pass; so the wasteboard would be level to the machine. But in the end, a planer is still a terrible way to surface MDF. DanCash is just better off getting a large surfacing bit and continuing with the original plan.
There is one other method you could try: Instead of surfacing the waste board you could instead surface the material you are about to carve.
You could even make small riser blocks that are surfaced and level with the machine and use those to hold the material. This is still not as efficient as leveling the washboard because the blocks would only be level to the area of the washboard they were surfaced on.
I have the bit, but where do I change the stepover in easel? I think this is the bit I was missing.
as I said, I don’t use easel, but I am sure someone will chip in.
What work area do you have?.
If possible I’d do 2 passes, one to remove most of the material and then a shallow one. Then it should be perfectly flat relative to your machine
Step over is represented as a percentage. Default is 40% I believe. You can find it in machine->advanced
If you use a 3/4 bit, 40% will work well.
I am going to use a device you can get a Harbor Freight that is a dial indicator. Here are 2 of them:
I have the digital metric one.
I will move it to each corner and ensure it is the same and adjust y rails by loosening the bolts that are in the T-nuts and manually moving with a shim to get it the right height. Once all 4 corners are done I can then check for any surface defects. If there are any then I can use the machine to remove areas to make it more level. I agree on the fact that a planner would gouge the surface too much and result in a uneven surface. Use the machine to get the bed level. (actually its not leveling its more like making the bit perpendicular to the bed so that your cut is even.
There is another user that made a 3d printed item that you can connect the dial indicator to.
If anyone who does not have a 3d printer that wants one I can make it as I have one here and plenty of material.
I am unable to find the dial indicator post for the one I 3d printed. There is another I did find but it has more parts to it.
The one I found has a single part that hooks directly to the side of the spindle holder opposite where you tighten to keep your spindle in.
Here is the thingiverse model file for those of you who have your own 3d printer.
Demo project: http://easel.inventables.com/projects/3n2M-mxnu_PJRSfQgiQFvw#
A Feed rate of 100 IPM, cutting 0.05" will take 32 minutes.
Your machine should be able to handle it.
If you think 100 is too fast, try 50. It’s 1 hour then.
Also, if scared, double side tape some 1/2 MDF for a practice run!
I recently checked my bed’s levelness.
I mention it in my latest blogpost: http://www.manmademayhem.com
I don’t go into detail, but I basically did what Stephen Cook describes, and it has a picture. I mounted my mm gauge with a scrap piece of wood.
Long story short: it is within 0.1mm between all mounting points, so that is as good as it is going to get, but still there are pretty large discrepancies down the center of my bed.
My machine is 1000x1000 though.
This is what I am running at now. Turns out I was just an idiot. When I was putting in my bit size I was typing .75 then hitting enter…which unbeknownst to me, was changing it to mm. And my bed was pretty level already, but it seemed my MDF wasn’t perfectly flat everywhere(I made my own wasteboard). So milling it down will guarantee it is level all across. Thanks for the help all.
I have the 1000 x 1000 mm machine too.
Found out that the waste board is warped not just on the edges but in the center too. May have gotten moisture in the shipping.
So for now what I plan on doing is replacing it with a better setup. the machine does not have a bottom. Its designed to use the MDF as both the bottom (I call it platform for reference purposes.) and the waste board top. I want to have a flat platform to put a MDF waste board on. So my plan is this. I am going to first mill down the surface to get rid of the uneven surface then saturate the MDF with a wood hardener so it becomes stiffer and is less chance to warp with moisture changes. Then I will put it back on the machine and mill it down to spec close as I can get it to flatness. This should give me a nice solid surface until I get the new stuff I plan on using. (A Extruded aluminum platform.)
With the gauge mounted to the tool support I move the machine by hand to all 4 corners, with some adjustment you can achieve all corners withing 0.05 mm. With thicker MDF (I use 18mm now) it is easier to achieve a better result.
This also brings the Y axis parallel.
Yep, that’s exactly what I plan to do too unless I can get my hands on some Valchromat, which is naturally water resistant (and lubricates the bit if the bit cuts into it).
I did research for valchromat and they have a different name for it.
here is a thread on it with some sources.