Alignment of mpcnc

So what if you aligned the 4 mpcnc posts like they align the mft table in this video!!! I may try it! I may make my own jigs. Then instead of 20mm holes try for 23.5 (if that drill size exists) and have the emt sink into them. Thoughts??

This jig could be cnc’d Drilling New MFT Tabletop With Hole Boring Jig | Deep Dive - YouTube

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Standard disclaimer - You do you with your tools in your shop. I’m just providing my opinion.

As I understand it, the benefit of the MFT table is that you can easily set up jigs or fixtures on standard spacing and angles to allow for work table flexibility. Since the MPCNC feet only need to be attached once, I don’t know that there’s a lot of benefit to developng a complex jig. I don’t think you’d be able to just slip the upright legs into holes in the base without securing them in some sort of foot.

What problem are you trying to solve?

If it’s to be able to have adjustable height, then you can bore the pass-through holes for the extended legs oversize, and precise placement of this hole is less critical since the feet (which are secured to the base independently) control the squareness of the rails.

If it’s to be able to quickly change the spacing of the rails (e.g. have a smaller footprint to improve rigidity when working tough materials), I’d probably just print three extra feet that I could attach where desired to establish the smaller machine size. For simplicity’s sake, I’d use the X Min/Y Min foot “as is” and I’d have one additional foot along each of the existing X min and Y min rails so they were outside of the working area (these could stay permanently attached depending on your leg height), and have brass threaded inserts for the last “temporary” foot’s location which would end up inside the working envelope of the machine when it was in its larger configuration.

If you’re looking to establish a standardized grid for aligning work, I’d get the machine built out and then use it to bore the holes. No jig needed, and the programming of the job would ensure parallelism to the machines axes.

It just occurred to me that you might be thinking of boring out 4 (or more) of the MFT holes to use an existing table as the basis for a temporary MPCNC. Intriguing idea, but I’d be worried that the rails would get twisted or bent when setting up/tearing down or while it was in storage. Right now, my Burly (cutting area about 12"x20") is mounted to a 1/2" plywood base with a 3/4" MDF spoil board added on top, and this is simply clamped to a counter top in my workshop. If I need to reclaim that space, I can pick the whole thing up and hang it on the wall without worrying about it getting out of alignment when I put it back in service.

Not trying to solve a problem. In fact I almost deleted this after I posted it.

It would just give PERFECT alignment that is all. Maybe I will ask Ryan just to delete this topic. I do not want to cause any grief. It was just an informational discussion. The Hypotenuse angle for the perfect box.

Then on the 4 corners drill a 23.5 hole and place the 4 feet.

Nothing really. Just a thought. Probably should have just kept it to myself. Also was thinking the whole MFT thing would come in handy for the cnc also.

Sorry!

Yeah, @Ryan Can you delete this topic please, I think my ramblings will just cause problems.

I apologize.

No reason to delete the topic. My takeaway from the video was the use of two hinged straight edges and the Pythagorean theorem as a way to create the square leg layout. I think the concept has merit especially for someone who does not have a large carpenter’s square. Measuring the diagonals and adjusting is a pain.

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Please don’t ask to delete the topic due to my comments.

One of the reasons I spend some time almost every day on these forums is that folks folks post their out-there ideas looking for feedback, and others can post honest, trying to help each other comments.

I’d hate to think I’d thrown a wet blanket on that kind of brainstorming and sharing.

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I will delete it if you would like but I don’t see a reason to. It is informational and shows a different way of doing things. If someone wants a table with easy layouts this is a good way to do it.

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I really do not want you to think it was because of you that I wanted it deleted.

I just was surprised how easy it was for the alignment to be perfect. I wanted to see what others thought.
I was not really looking for anything more.

I am going to most likely extend my mpcnc to 4x4, (have not quite decided yet) but if I do. . I think i may try making the 4 posts using that design and then countersinking the 4 posts in the top. drilling through the bases that I printed, then the posts should be as perfect as I can get them.

I am sorry if I concerned you that it was because of you. I sometimes post without thought, sorry.

Regardless of your intent, the video you shared a was fantastic example on how to get perfect alignment. Nothing wrong with sharing something you find interesting…

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My goal in posting my thoughts was to save you work on a complex jig. Sometimes when starting down to road to use a new tool, one may not fully grasp the capabilities of the tool itself.

I vividly remember back in the late 80’s having to fax a resume and job application for the first time. As I’d been trained to keep copies of everything I sent, I photocopied the resume, cover letter, and application form so I’d still have them once I’d faxed them in. Luckily, I was alone in the office when I ran the docs through the fax machine and had my face-palm moment that the extra copies were a waste of time and effort.

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