Continuing the discussion from Fixture table build…the hard way:
Okay, whatever I did, it didn’t carry over. Anyway, I was trying to start a new thread, and refer to Wisco’s thread while not stepping all over his, but nobody ever called me tech savvy. I finally got around to starting my own table, 36” x 60”, but I was going to document and photograph as I went, and then just post it all up when I got done. I got one row shy of halfway done and figured I would swing the template 90* and check out how the holes lined up- THEY DONT!
I am beyond mad right now; and here’s why:
I’ve followed Wisco’s entire build, and probably read it twice; apparently I missed the part about the template not lining up when he turned his 90*, I just read his thread a third time, and I caught the part where he mentioned, as did someone else, that there are potential issues with the templates being off when turned. Had I paid better attention, as well as remembering that fact, I might have been able to correct, or perhaps prevented the problem from happening.
I’m retired, so I have all the time I need, and have been working at a snail’s pace to make sure everything works as expected; I literally check the clearance of the cutter every hole; yes, there actually is a slight gap between the cutter and the hardened drill bushings in the template! The only thing I DIDNT check was the template itself; shame on me, I guess, for trusting that the $259 template was accurate from the beginning…. Yeah, I’m looking at you, Jason; one guy has an issue, hmmm. A SECOND guy has the SAME problem; double hmmm. THIRD guy has the SAME problem, ok, WTF man?
And here is where it gets even stranger; once I realized that the template didn’t work when turned 90*, I started thinking “oh crap, I have a LOT of fixtures that aren’t going to work”, it occurred to me that the most expensive one was the 3 axis XL square; another couple hundred bucks out the window! So I screwed the pins into the bottom, and IT FIT! Then I proceeded to try the square in 6 or 8 different places, and rotated it as well; IT STILL FIT! It doesn’t make sense, but it actually worked. It also doesn’t change the fact that the template(s) was/are not made correctly, and if I continue using the template as it was intended, and demonstrated, how far off will the hole pattern be over 60”?
I guess what I’m saying is that even though the 3 axis square fits, and smaller, shorter fence blocks fit, it doesn’t matter if the overall hole pattern isn’t equal between the x and the y axis; isn’t THAT the purpose of a fixture table in the first place? Because if inaccurate spacing is what I wanted, I would have spent a few more bucks and just took the plate out to the range and used the 50 cal on it; seriously. Not quite sure how I should proceed at this point….
I believe it was Erle who began using a dial indicator with each new placement of the template but he hasn’t updated his thread.
I haven’t performed dimensional verification of the grid or checked the template across a greater selection of test holes for fitment but of each time I have tried, the distance is greater along the length every time.
However, I use the fixtures a lot. Some holes will be snug and it’s more of a vertical alignment issue/user input because they will come out easier than they went in. There have been spots where I’ve encouraged them with a dead blow but will drop on their own after the first tap.
The more I use the table and the holes lap-in, the blocks and clamps drop in with ease. So far I haven’t encountered a spot where a fence block won’t fit X, Y or 45*
When does the video drop for the .50 cal range/fixture table? 
Now you’ve really got my curiosity peaked; because in my case, the hole pattern gets more “crowded” along the length, which is the opposite of what you have. I will assume that because you drilled the skirt pieces first, you drilled them length wise, and then while they were still attached, you flipped the template 90* and started working your way down the length of the plate. Did you then use the first holes in the skirt as an initial point to locate the template, and just skip a hole? Or did you start fresh using the short edge and work independently of the holes already drilled for the skirt portion and just not cut them off until you were completely done?
Let me make/edit some photos that illustrate better than word salad.
Yes, I need to apologize for the salad, but at least I read it and tried to condense it the best I could, because it started out like a word buffet….
All holes were indicated from the edge and/or corner utilizing the guide pins for the template. The grid is set to the default 2” from the edge. To clear confusion, the skirts were drilled prior to cutting for the mag base. The template was set from their lower edge for 2” pattern.
Here’s a bunch of random samples from today. Last pin is 2-3-5th hole before no-go. Roughly 1/32” of max variation by end of template. It becomes increasingly noticeable to the eye lookin down the bore of the templates.
This illustrates the blocks fitting where the template won’t
Length axis variations
Grid dimensions
Skirt blocks
This is the orientation in how this table was drilled. Pins drop with the most satisfying sound across all holes. Also long side skirt blocks.
Blocks where template disagrees again on 24x36 table
Random samples and pin locations
Same test on the unfinished 30x60. The grid falls short by a 64th. The machinist rule would catch the end of the yard stick.
Direction of drilling
90* typically only 2nd or 3rd pin would drop in either direction of “zero” for testing. But you can see the fence blocks all drop.
I understand your frustration and I hope it works out for you. Hope this helps restore your excitement in the project as well as for others who want to go this route. Attention to detail is a must and my accuracy/attention falls somewhere in the middle for what’s achievable with a job like this. Certainly there’s some folks who could really dial in the process with instrumentation and more patience.
In the end it was worth it as I can achieve an incredibly higher level of quality than working on wooden benches or wavy concrete floors. I’ve used the tables for not-welding jobs etc and it’s just too cool to set up some blocks, shims etc and accomplish a task.
Forgive my comprehensive abilities, at least for the moment (no coffee yet). If I understand correctly, the holes in red were NOT used to locate and/or hold the template for drilling the holes in yellow, correct? Yes, sometimes my blueprint needs to be made in crayon, just to clarify.
Correct.
There’s a 1/2” error along the cut/parting line because the skirts butt against the bottom of the table surface to have an effective 6” surface and 2” grid and hole C/L to edge.
For my table dimensions, I was always able to indicate the template from the edge of both X & Y with the guide pins to begin the 2” pattern and continue production with the tacking bolts. No measuring or conversions etc needed or floating of the template in space.
Thank you for clarifying that for me. Because if you did in fact use the holes in the skirt to locate the holes in the main table area, the fact that the fixture plate is inaccurate would have likely caused a whole new level of distortion to the overall hole pattern.
I was reading through some of the other threads, and at least I know why and how the error occurs; but it doesn’t change the fact that not only do they know they have an accuracy problem, they have yet to fix it. At the very least, they could have created a category dedicated to dealing with THEIR OWN product’s shortcomings, and the workaround. At best, issue a product recall, but we all know that ain’t happening.
You are definitely highly skilled and it shows, you do some amazing work, keep it up! As far as my table goes, I’m not giving up on it at all, I’m just super pissed off that 48% of the work already done is not as accurate as it should be, because (more than likely) everyone has paid good money for something that should have never made it past Q.C.. But at least someone figured out what the issues were, so I’m gonna go with Erle’s method for the rest of the drilling, as it appears to be the correct solution; I thought about doing the same thing before I knew about his thread, but wasn’t sure if it would possibly magnify the accuracy issues.