MakersmadeCNC sled accuracy

Hardware Sled
1

Hello, I am in the process of assembling the sled and Z axis (I ordered it from makersmadeCNC for blackfriday and just finished assembling the frame) Yes I know, I was a bit slow but I tried to make it mm precise with skirts wall mount, etc…
Anyway I was a bit lazy and ordered the premade sled . I got a friend who has his Maslow since last summer tell me that putting the router dead at the center of the circle was pretty important for accuracy…
I was ultra carefull in assembling the ring to make sure that every little screw was sub mm precise in the predrilled holes. This resulted in the ring pulling on all three support by 1-2 mm. But I don’t think it is a problem if well balanced
Then my idea was to use the routed helper concentric arcs as guides to center the router.
Tracing lines and trying to figure where to place the 3 holes for the ridgid (aeg) router.

While doing that I noticed that the center large hole was about 2 mm off center… and that the hole bottom right part was routed at an 8° angle… (wonder how that is possible) the reste of the hole being pretty perpendicular to the sled plane… (was the sled being routed on a maslow and the sled top lifted by that much?)
Anyway…after tracing more lines using the ring supports as references I noticed the routed arcs were also pretty much off.
So what I finally resolved to do was unscrew the ring and attach it at the bottom of the 3 stands so I could trace the inner circle of the arc (where the wheels roll). black pen
I suppose that is the best (and only) real reference one might be able to get. Tracing it confirmed my thoughts that the helper arcs and the center hole where pretty much off.
So that said I lost a good 2 hours with pen and square ruler trying to straighten this out.
I am not sure my way of finding the 3 points on a concentric circle to the ring is the best but I would not recommend anyone using any of the “helper arcs” features of the sled.
In fact, I wouldn’t actually order the sled at all because if the helper features are off, I don’t see the point…

just my 2 cents.

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It has been awhile so I could be mis-remembering this but, I think the most important aspect of all is the accuracy of the measurements to the center of the router upon calibration.

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Well, TBH I haven’t calibrated yet, and I’ll take your word for it…:wink:
but from what I read… it needs to know the “rotational radius” and it probably doesn’t help if: radius right = radius left + 3mm

4

you definitely want the router in the middle. There is a 3d printable alignment guide in the community garden. Alternatively use a Olaf circle cutter https://www.amazon.com/s?k=olfa+circle+cutter&ref=nb_sb_noss_1

currently testing this 15x15 laser cut sled, 14 lbs, red holes for ring arms, blue hole for R22002 ridged base mounting.

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that has mounting holes for C beam, or meticulous like Z axis, ring or linkage, over or under vacuum, etc. After I test will release the DXF to the community. My local laser cutter charges around $40 for a single one to be cut, online I found https://www.2twentytwosteel.com/ that can laser cut and ship a base for around $55.

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5

Thanks for that I guess paper printing of the holes position would be good enough …
Looking at your drawing, I can’t see the ring actually nor the 6 little holes used to attach each of the 3 ring stands…

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2 screws through a 1/4" steel plate is enough for a metal design. they are shown in red

the wood design might need 6 of those tiny screws.

ring is not shown, only attachment points for the ring.

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Check this out, it’s a printable alignment template for the ring system.

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Thanks… a bit too late I just screwed it in :wink: but certainly useful for the community!!