CNC Build Ep 3: How to Make an Avid CNC Very Precise - Aligning the Linear Rails!
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- Опубликовано: 27 июл 2024
- CNC Build Playlist: • Avid CNC Build
Ep 1: What CNC To Buy - • CNC Build Ep 1: What i...
Ep 2: Welded CNC Table - • CNC Build Ep 2: How to...
Ep 3: Making an Avid CNC Precise: • CNC Build Ep 3: How to...
Ep 4: How to Tram a CNC: • CNC Build Ep 4: How to...
Ep 5: Automatic Tool Changer: • CNC Build Ep 5: How to...
Ep 6: ATC Tool Rack Build - • CNC Build Ep 6: Automa...
Ep 7: ATC Setup in Mach 4 - • CNC Build Ep 7: Custom...
Ep 8: ATC Tool Heights - • CNC Build Ep 8: How to...
Ep 9: ATC Post Processor Setup - • CNC Build Ep 9: ATC Po...
Ep 10: 3D Printed Dust Boot - • CNC Build Ep 10: Print...
Ep 11: Improving the Avid CNC Table - • CNC Build Ep 11: Impro...
Ep 12: CNC Spoilboard - • CNC Build Ep 12: Make ...
Precision Level: amzn.to/3oa3THl - $129
There are better machinist levels out there, but this one had a good price to value ratio, and it is a tool that I won't need to use a lot.
Dial Test Indicator: amzn.to/41CwqUG
I have a cheap ENCO one, (now MSC Industrial), but any one that goes from 0-1" and has .001" indications will work fine.
Digital Calipers: amzn.to/3myx7Q0
If you don't have digital calipers, then buy a cheap one to get your started. I own a MITUTOYO one now, which is pretty decent, but expensive.
Other notes: this is a good video in general for CNC Woodworking. If you do CNC wood stuff, and have a DIY machine, then you might find it useful information on how to fix some cutting issues due to the machine setup.
Thanks!
Corbin Dunn
www.corbinsworkshop.com // CNC files, and Products
www.corbinstreehoues.com // Blog, latest stuff
Chapters:
0:00 Intro
0:31 Problems with the Linear Rails
2:13 Fixing the Y Axis
3:58 Fixing the X Axis
5:08 Conclusion
* Some links are Amazon Affiliate Links, where I earn a small commission if you purchase the item. I only link to them because I have bought and used some of these items, and they worked well for me.
#cnc #cncwoodworking #avidcnc 
Хобби
2:56 am I missing something, or is your indicator reading dependent on the flatness of the particleboard it's sitting on?
I realize I didn't explain that part really well; I put the indicator down on the MDF only to watch how much I move the rail up and down. So, if the level shows it being a little low, I move it up about .0005" based on the indicator.
I definitely don't want to level the table based on the indicator on the MDF -- that would only make it as level as the MDF and the table itself.
I'll pin this comment to the top so other people can see it!
@@CorbinDunn Ah, got it.
These videos are incredible, making me want to do all the upgrades to my avid. Thanks for sharing all of this!
Awesome, glad they are helping!
I'm liking these vids.
I'm now a subscriber.
Welcome aboard!
Super clever my man, impressed you caught that. Hopefully more people they have Avid CNCs watch this!
Thanks!
Glad to see someone else discovered the inaccuracies incurred by using the Avid jig and following their alignment procedures. I discovered the issue much further along in the build when I was surfacing the spoil board. I used a much less rigorous procedure than yours because the way I have my spoil board mounted made removing the dust covers too disruptive. I got my rails to be just barely within acceptable limits but when I replace my spoil board later on I plan to use your process. Have you had any communication with Avid regarding this issue? They really should do something about it.
It's good to know I'm not the only one who discovered this! I posted the video on Avid's forums, and I know they keep an eye on things over there. I haven't reported it to them directly. I understand why they do this sort of thing in the directions; the jig makes it easy to align everything, and it is relatively accurate. Overall, it would only cause a .005 to .010 issue, which isn't too bad over 8' of length. My jigs might have just been poorly machined.
That part of the jig dimension dosent matter. Even if off, you could have just used one jig along the track as you tighten.. I'm not even sure how "precise" that aluminum extrusion is.. Nice tips! I'll have to check my jigs as I'm 75% done with my build. Thanks!
YES! You are observant - I measured the wrong part in the video, and in the description I noted that later. It's the part from the machined area to the part that sits on the rails; I measured this, and my two varied by 0.010, which is even more than what I (incorrectly) measured in the video. You can use the same one; the hard part with that is re-aligning it. I think the precision level is the best way to ensure it is really flat. YES - the extrusion is probably not very precise...this method will accommodate that for the z-axis, but the x/y could vary, so it is still limiting the accuracy of the machine.
@@CorbinDunn Wow, 0.010... I'm really worried.. My machine is 2 years old.. I finally just got time and space to set it up.. I leveled my legs and base but ill have to find my calipers and see what two year old blocks come out to be. (by the way, you could add that text in the RUclips editor when you're measuring the jig so you don't need to re-edit or upload.) but I'm not sure if it displays on every device.. at least it didn't 12 years ago when I made RUclips videos.
You're right, the extrusion isn't necessarily perfect, and using a level isn't precise either when talking about minute adjustments. The level itself isn't necessarily perfect, I always check them against itself by flipping it over (rotating the short way, not flipping end to end or you'd have the same thing) and checking that the bubble reads the same when upside down. My 6' decent quality level has an X sharpie'd by one of the two horizontal bubbles because it reads slightly different when I flip it over. I'm in the process of leveling my own 5x10 right now, using a laser on the linear rails after basic leveling of the top surface, will be uploading a video when I'm done...
Wondering why you did not just take the jig to your mill and make it a little smaller?
That's a good idea, I definitely should have done that!! I actually didn't notice the problem till after I was done; I was trying to figure out why things were so far out of alignment, and I realized the two pieces were not the same size, and would cause the offset I was having to correct for.
Dang, I didn't even think to check that my jigs were the same thickness. 0.005" difference is pretty bad for what should be a slam-dunk repeatable part to make (they only need precision on a single dimension). Personally, I would have just orbital-sanded or machined down the 0.005" so the jigs match. I'd be a little hesitant with your method since it's such a small level (doesn't span much distance), but at least with your method you aren't relying on the aluminum extrusion to be perfect (as you are when using the jig).
I do recall using the jig in the middle of each rail-span. Those rails are heavy, and they certainly have measurable droop when spanning 4+ feet. Avid should have included 3 (accurate) jigs.
Yeah! I thought about putting the jig on my knee mill and taking a bit off. In the end, I thought this was more accurate. My 4’ level says it is flat, but that thing isn’t too accurate.
Ah! I just realized I measured the wrong part in the video. I should have measured from the machined bottom area to the lip that the rail fits on. I re-checked mine, and it turns out they are .010" different! That really indicate a machining problem when they make that piece.
They should just machine the jigs in one long length and then split it in half , then they will be exact
🤨It's beyond ridiculous how avidcnc failed to make sure their linear rail alignment jigs were not made accurately.
It's definitely a manufacturing mistake. I did bright it to their attention, and they were supposed to look into it, but I'm not sure what became of that. I could also see an easy mistake where they used one from two different batches; I'd hope that a pair from the same batch would be the same size.
Why would you assume your WELDED table is plane with 2 sides or even parallel? Never happen. There is also no accurate method you can use a machinist level every 8 or so inches to achieve a linear plane. I believe after seeing your mismatched gauge blocks you have improved your machine though. The z axis heavily weighted to one side with a short mounted axis and reversing directions almost immediate will cause unsatisfactory inaccuracy's also. If your only batching out smaller items on a production basis it matters not. Especially working with wood that changes by humidity. I have seen plywood measure 10-12 thou variation on the thickness over the perimeter of a 4x8 sheet. There is Zero cnc machines that come in a box via UPS of your size that can assemble in hours and achieve machinist tolerance's with wood or any material. That said, nice machine for cost/value.
Yeah, you are right -- it isn't possible to ensure the distance between the long y-axis is the same, and I'm basing mine on the accuracy of the aluminum cross members. But I think the machinist level definitely helps with accuracy in getting the table in a linear plane; the side axis may not be perfectly parallel though! A lot of professional machines claim a " tolerance level of +/- 0.03 across 12 feet" -- 30 thou over 12' seems pretty big to me! (I'm quoting Phantom CNC's spec sheet.). For a wood machine, it all seems somewhat negligible for the reasons you mention (movement)