Wood is not a precision material. It expands and contracts with humidity, a lot, more than most people realize. Then add the fact that it is fibrous and spongy. Every material has an appropriate, easy to hit and hold under normal circumstances, tolerance.
A full depth pass is 100% required for tolerances under 1mm, in all materials, that is just a mistake, not to do it, but you know now. Can you hit 0.15mm tolerance, 100%, I consider that simple, as in most people can get within that range without trying. But if you hit that in the dry summer after noon that is not going to be nearly the same number in a wet fall morning in wood.
0.05-0.02mm is where most people can easily get with some practice and tuning, easily with these machines.
To be clear, any CNC can hit most reasonable numbers. The differentiator is how easily each machine can do it repeatably. The issue here is it is all based on your CAM.
You went from machine building and wiring issue directly into 0.05± mm tolerating. You have to be reasonable with what you are trying to do. Do you want to press fit your end mills into the holders or do you want them to drop in and out easily so you do not cut yourself pulling and pushing on them.
The key in my questions was ‘accurately’. Using the grid (as someone else suggested) or the right mouse button will only give an estimate, since EstlCAM doesn’t seem to have any object snaps that I can find. That’s sort of why I was asking. I’d like to be able to confirm that my drawing elements are actually the size they’re intended to be.
You can make the grid as small as 0.5mm x 0.5mm, so it should get you reasonably close for most purposes, certainly within 0.1mm by zooming in But if you are looking for accuracy to <0.1mm, then no, the grid would not be your tool.
Mine will provide the X & Y coordinates of the mouse point, so a bit of math could provide measurements. But it doesn’t provide the diameter of a circle or the length of a segment, as far as I can tell. Maybe there is a setting somewhere that changes the mouse button behaviour???
Yeah. As long as you are relatively close it seems to snap somewhat, but you have to be real close. Its not for exact measurements for sure, but it can give you a good “eyeball” measurement no problem.
@Elmojo , I think that you are over-thinking this. If the object is to confirm that the EstlCAM drawing is the same size as the CAD drawing, then measuring a 6.5mm hole should be a fairly simple exercise using the grid set for 0.5mm, or zooming in and using the center click and drag method, even without snapping to the line. A measurement error of 0.01mm isn’t critical for your purpose (IMO)
Very likely.
Please remember that I work in the engineering world, where there are 2 types of accuracy - right and wrong. (not really, but I hope you get the idea) Either something is the correct size or it’s not. That is of course a simplification, since there’s always a tolerance to consider, but I typically work to 2 decimal places for most of my work.
In Civil Engineering stuff, that means accuracy of 0.01’, which is about 1/8” (3mm).
That sounds like a lot, except when you consider we hold that tolerance over a distance of hundreds of feet in some cases. That doesn’t mean it will get built that accurately, but that’s what the design calls for, and that’s the point.
I design for what I want, not what I expect the output to maybe be if the machine is having a bad day.
I like to be able to design to the hundredth of a mm, then adjust for the inability of the machine to hold that tolerance. I do this all the time on my 3D printer or laser, when I have to pad out a dimension to allow for nozzle thickness, or resolution limit, or layer height, or laser beam spread, etc…
I just am not used to working with software that essentially says “eh, close enough mate!”.
When you import your cad file you know exactly how big it is. In ESTLcam you are just making sure you imported using the right units. Close is all you need. You will know if you are 10X off or 25.4x off.
There’s a saying that I’ve heard used by many carpenters/framers (house builders):
You’re not building a (F%$#ng) piano!
The meaning is that when working with wood in general, and especially structural lumber such as 2x4 framing, being out by 1/64" (0.4mm) or even 1/32" (0.8mm) isn’t a big deal. Depending on the application, sometimes anything less than 1/4" difference from specification is ignored. The wood will bend to shape to cover minor fluctuations, and the end user will never notice if the wall bows by 1 or 2 mm over a 20’ span.
Even in cabinet making, differences of <.5mm are frequently not too concerning, given the propensity of wood to swell, contract, twist and otherwise change shape over time.
Another relevant saying is that perfection is the enemy of good.
I get where you are coming from, and if you were machining parts for an engine that required tolerances and clearances measured in the 0.001" , you would be correct. But woodworking is quite a bit different than metal working. Tolerances and clearances are different as well.
Are you sure that is not next, this could be the test cut for that.
I think we have gotten a little lost in the weeds. This thread is getting very jumbled. The rebuild is done. Elmojo, I think it is time for a new thread so we all stay on task.
I work in aerospace. Without good understanding of tolerancing, there’s only one kind of accuracy- wrong.
That’s generally not a good approach for working in wood. Tolerances will never be as tight as you are designing for, and you’ll be forever chasing things besides the machine (like humidity, and temperature, and dryness of your material, etc.)
Agreed, maybe a thread like “maximizing performance of a former basketcase.”
I agree with you all, and want to apologize if it looked like I was disagreeing at any point.
I was just trying to explain why I was approaching things from the way I was.
I genuinely appreciate everything you guys have done to get this machine (and my understanding of it) from a pile of junk to a functional CNC, but it may be that I’m just not a good fit for this community. I’m sorry to have caused drama, that was never my intent.
I’ll do my best to figure things out on my own from here. Thanks again for all your generous time and patience!
If I ever get this little project done, I’ll post it. It’s nothing fancy, but it’ll be useful, which is my favorite kind of project.
I marked this thread solved a while back, so Ryan, you can archive it or close it or whatever happens.
