View Full Version : Pro4x2 allignment/tuning tips?

07-21-2015, 10:33 PM
Finally got my linear motion parts together for the Pro 4x2 machine. I've looked around on the both the cncrouterparts site and also in here, but I'm not finding much discussion on procedures for "tuning" it (tramming z, etc) to make it accurate.

Can anyone point me at a thread here? Maybe It's something I've overlooked?

Base seems to be square, Y axis is perfectly parallel, X axis needs alignment to be parallel to the base, but the Z axis is dead square in the perpendicular direction. So I think I'm close. (BTW, I'm calling y axis the short dimension, and X the longer one since that's how it looks on a graph).

Also, how level is level? Checking it with my digital Stabila level, it is "between the lines", and perfect in what I call "American Mode". But when I switch to "German mode",
it is off a little at 0.05 degrees, is that close enough for accuracy (cutting guitar parts and fretboard inlays) ?


Carol in AZ
07-22-2015, 12:12 AM
I am wondering, too. But so far no joy from my request either. Are the only construction directions the graphics from CRP? Is there no written manual anywhere?

07-22-2015, 09:42 AM
to join the choir, i just assembled the pro4848 and i was surprised there was not a step by step instruction, there was the "tips and tricks" but there were a few times during assembly i would put things together and then have to take them back apart because i had done it wrong. some steps of construction are completely left out of the tips and tricks, and some are in there but have pictures of the old versions of machines that don't look the same.

i think their theory is that people who are interested in CNC aren't going to read the directions anyways, but i was really shocked there wasn't any real directions. I went through every box twice thinking they must be in the bottom of one of the boxes.

the other problem is that each set up is different, and if you got the DIY electronics or build your own that changes everything as well. i can see how making directions specific to every setup would be very difficult. when it gets to the accessories like limit sensors or setting up mach3 the directions are great.

in the end, its just that CNCRP sells a kit of parts which is different from a completed machine which needs assembly. they give us the parts but we have to build out own machine without to much guidance.

but with specific questions cory has always responded right away, even on issues which related to tying the CNCRP parts to parts i purchased elsewhere, like the spindle. he is very knowledgeable and helpful.

07-22-2015, 10:13 AM
I sort of agree with you, but I have to say that I did find it pretty obvious based on the drawings and "tips" section, but mostly because I have 25 years of experience as a woodworker and having to figure out the right order of assembly. The only redo I had (gantry to riser connection) was because I didn't pay attention to the tips section as to how may bolts attach to the gantry.

And as a (30 years ! :eek: ) software engineer, I certainly understand that NOBODY likes writing documentation! Heck, these days we aren't even commenting code anymore.

But, it would be nice to have a short and sweet one pager detailing the steps you can take to make sure everything is in alignment, and where it really matters.

Maybe this is an "open source" moment, and time to just start compiling a sticky post with contributions by the members/builders so it can be easily found?

Or maybe this is covered somewhere for similar machines (JoesCNC maybe?).

07-22-2015, 10:19 AM
i think you're right that most of the fine tuning is universal to all CNC machines, so looking throughout CNCzone will yield a lot of useful information.

07-22-2015, 01:43 PM
Hi all,

We certainly recognize the value in step by step instructions. We already provide step by step instructions for our Benchtop products, and are in the process of doing so for our larger format machine kits. We've recently made investments in software to help us with better documentation (as well as someone to use it!), and hope to be rolling out better instructions over the next two quarters.

We have had hundreds of customers assemble our machines with the existing plans and tips and tricks. I'd encourage anyone who runs into an issue or question to get in touch with us, as we try to respond as quickly as possible.

In terms of alignment:

1) We recommend using dual homing switches (on the two slaved axes) to square the gantry. You can check squareness by using your machine to cut a rectangle, and then measuring the diagonals. If you are out of square, adjust one of the sensors in or out as appropriate and re-check.
2) Tramming your router or spindle (which basically means aligning it to the z axis travel) often isn't necessary, but if you are seeing pronounced ridges on your cuts, you may want to add a shim between the mount and your z axis to tilt this back into alignment. A search on tramming a mill head should yield lots of good generic information on this topic.
3) After that, we'd recommend using a sacrificial spoilboard that you can plane flat with the travel of the machine.

Thanks to all of you for being our customers -- we care about your success and are committed to making the process of building our kits easier and better going forward.

Best regards,

CNCRouterParts (http://www.cncrouterparts.com)

07-22-2015, 05:46 PM
Thanks Ahren, that's exactly what I was needing.