Hey all, First time poster here. I’ve finally gotten my table rough assembled (pic below) for my Journeyman and am looking for some input on table flatness requirements. The top is 2 laminated mdf sheet. After laying a machined level across I can see that I have more than 1/32” dish in the middle compounded with a very slight twist (1/32” difference in corner-to-corner gaps).
My question is what are the requirements for table flatness prior to putting a wasteboard on? Should I start troubleshooting the last 1/32”-1/16” of dish or will my flattening operation take care of it? Also, what about the twist? Am I limiting the machines precision by leaving it, or is there a way to really dial it in during machine setup using shim packs for example?
The dip in the middle of the table isn’t really an issue, when you flatten the waste board it will fix it, just be sure your waste board is securely connected to the table so there are no gaps between it and the table. As for the twist you can shim it but it seems you have your machine on casters so as you move it around that twist might change over time as the table resets to variation in the floor. Might be worth moving your table around to see if the twist changes.
I would do everything possible now to get the machine itself as square and in the same plane as possible. One thing I’ve done is place fishing line taught over the Y rails on opposite sides. Pull them tight (mass attached to ends), and they will cross in the middle. A gap will reveal issues. You could use this method to monitor changes as you add height with shims (if that remains your plan). You may however find that these small differences will remain over time as the microclimate in your garage (?) impacts the wood, or you roll the table to new work areas in the space. I imagine periodic waste board surfacing will take care of the smaller differences, and may be a good ongoing strategy for their elimination.
You know the casters are leveling casters but I hadn’t considered the base might be flexible enough to fix it by adjusting them. I’ll report back thanks!
remember that in case the two fishing lines touch, you must first swap them over (the other one down) and there must not be a gap either to be sure the four feet are in one plane.
I found this method recently and thought it was clever - more effort however - and it generates data which I always like! Geared towards tramming, but has relevance to our discussion of the Y rails.
Instead of fishing lines or wires use a board that spans two diagonal corners on the table where the feet for the rails will go. Put marks on the board where they touch the two corners. Mark the middle of the board and measure the gap between the middle of the board and the table. Rotate the board to the other diagonal corners (aligning the corner marks) and measure the gap in the middle. If the gaps are different then use shims on the corners that had the smaller gap to get the gaps equal. The same shim thickness is used when attaching the feet to the table. You should be able to measure the gaps to feeler gauge accuracy (.001"). When the gaps are equal the corners are coplanar.
Hello Jason and welcome to the Onefinity family!
I have the woodworker version and purchased the QCW frame for it which takes care of any leveling issues. I’m not sure if they have a QCW frame for your journeyman size but might be worth checking out. I love my setup!
Hey guys I didn’t follow up on this after getting it set up! So as was suggested, I used the fishing line trick and was able to negate the small amount of twist by adjusting the leveling casters. It worked wonderfully and it’s as flat as I can measure now! Thank you all so much
Aiph5u
(Aiph5u (not affiliated with Onefinity))
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Hey Jason,
your table turned out very nice!
Is this maple veneer on the double MDF tabletop?
What kind of wood did you use for the table frame?
Did you do the mortise and tenon joint by hand?
Good idea with the adjustable height leveling casters. Does the table stand on the fixed feet and the wheels are no longer on the floor when the table is not to be moved, or are the wheels still in use after the height is adjusted? There also exist casters where you can adjust the height while the wheel is in use, e.g. like this one.
I just did a web search and I also found these interesting (although expensive), because despite the height adjustment, the wheels can be activated with the foot:
