Workpiece XYZ 0

#1

I have been trying to figure out how best to achieve this without actually having used a CNC. I have seen a number of good solutions the first one being from this kickstarter Z probe and then the Shapeoko solution I referenced in my post on adding cool functionality to improve their machine. I thought, at the time, a static fence with endstops as well as a recess for the probe would be a great solution.

Then I saw another video referring to a probe like the Shapeoko but with a circle removed from the top to allow finding the XY corner of the workpiece irrespective of the diameter of the bit. It was $35 from china and seemed cheap and moved around in what seemed like the breeze.

While researching this solution I came across a website called “The Makers Guide” with a product called the triple edge finder($77 USD + Shipping). This solution seems like it covers everything I am looking for to accurately determine XYZ 0 on the workpiece.

http://www.themakersguide.com/home/products/triple-edge-finder-2

You know what they say about things you find on the internet, so I am wondering if anyone on this forum has seen or used this type of product. As I think it would solve many of the issues I can see with needing a reference point that is repeatable and accurate. There are comments from 2013 - 2019 including ones by the creator as well as a blog that has posts listed from 2013 - 2017.

Because I have lots of free time, and a 3d printer, I am printing up a model that I put together to try and wrap my head around it a bit more. Then add a threaded insert, and some copper tape, I can see a bit more how it can work.

If this is a useful product I hope that the guys at Sienci Labs can get a few that us Canadians could order without the extra ‘fee’s’ when shipping something from the states.

#2

gnuthbie, the rub I’ve seen using a block of any kind to probe with is whether the gcode sender you’re using does probing, and how it does it - Z only, X & Y individually, or X, Y, and Z all in one operation. I think Universal GCode sender does all 3 but as separate operations. bcnc, and I think Candle and Source Rabbit, does it all together. I think Carbide Motion does a ll 3 together, but I don’t think it works on anything except Shapeokos.
Based on some comments Andy made in of of the videos, I’m leaning towards only worrying about the Z because for the kind of jobs I’m planning on doing will need the X and Y set based on the 0,0 for the individual part, and it will change a lot.
Like you I was pondering this a while ago and drew up one like you mentioned - 90 degree slot on the bottom to set the X and Y, and a hole on top centered on the corner below - in Fusion 360. After all, we’re going to have machines capable of milling aluminum, so why not make one. I think it should work as is. It’s pretty simple to model, but I can send you - or anybody else interested - the file.
As I’ve said in other posts, for me a large part of the fun I’m looking forward to having is in figuring out how to do things. I really like the head scratching that you do to make progress. Sounds like we’re in for a good time.

#3

I was wondering about how they were implemented when seeing sites selling macros for $1 to run a calibration probe. I guess I will see how it all looks on the raspberry pi and if the 4" high resolution screen will display everything.

For me it comes down to reducing the known unknowns before the machine arrives. I did a similar thing when I got my 3D printer 18 months ago. Spent 2-3 months making sure I got the basics down so that when things did go wrong I had a good reference and starting place. It was always something simple that was the issue, but it may have been a month of head scratching.

But I do agree that this will be a good time when the machine gets here. The tweaking is always the fun part to get the machine to work just right. The 3D printer was about 12 months, of spare time, but that was because the one I purchased was a good platform to learn with and then upgrade. This one I expect is a much easier path in that respect since a bunch of that time shouldn’t be making parts just to get it more reliable.

One thing that should be fun is modeling something, 3D printing it to see if everything works as expected, and the producing it on the LongMill. The XYZ probe could be a very good mid term project, as I don’t expect many of my first projects will be in aluminum.

#4

I’m a retired mechanical engineer, and I learned early in my career that the best problem is the one you discovered and solved before it had a chance to bite you. That means preparation and anticipation and attention to details. It became the part of engineering I really liked - getting way deep into a process or system early on and being ready for the inevitable supplier’s delayed shipment, or the drawing error, or the unexpected weather. For me it made complicated design jobs the most rewarding.

I came close to buying a commercial hobby-level CNC router a couple times, especially during Carbide’s holiday free shipping sale, but I always found things that made me stop. The Long Mill addresses two of the biggest issues for me - the stiffness and the screw drives. I also like the idea of raising the mounting blocks to fit taller projects. Maybe I delayed for good reason! August may seem a long way off, but after waiting for the Glowforge laser, it sounds like it’s right around the corner.