Frame to handle 4x8 or 5x5? Chain length?

Hey all. Forgive my hand made illustration but for noodling, I’m faster this way. I’d like my frame to be able to handle both 4x8 and 5x5. My solution is to have a removable skirt below the portrait 4x8 where I could drop in a 5x5. I’d have to add side skirts also for the smaller width.

My next variable is chain length. I already bought extra chain but I’d like to minimize the extra.
Question 1: do my calculations make sense? How long is the stock chain since I’m showing the basic 4x8 as needing 125”. The 5x5 comes out shorter which is good.
Question 2: how much extra chain should I have for sag and to make sure it doesn’t unspool? How much is too much?

Kid activities are at a minimum this weekend so I’m playing in the garage!

Basic 48 should be basic 4x8 and 55 should be 5x5. Apparently the asterics adds italics!

Good question. Around here all of the fancy pants plywood is five by five.

I guess the easy answer is to rotate the sheet 180deg and cut the rest of the design. Another thought is to make a taller frame .

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Question 1: do my calculations make sense? How long is the stock chain since I’m showing the basic 48 as needing 125”. The 55 comes out shorter which is good.
Question 2: how much extra chain should I have for sag and to make sure it doesn’t unspool? How much is too much?

the stock machine comes with 11’ of chain, so if the basic system needs 125"
from the motors, that leaves 7" left

Is that enough chain left over?

Thx for the reply!

the 7" left over is enough for the stock build.

No problem. See this post in Is milling possible? - #6 by Sharpsburg_Woodworke you’re in good company!

Lol. Hey, watch it. That is what I call the original way to do cad.

Looking forward to what you come up with @Mattintx, since I’ve spent the last week working up a frame design to solve the same problem. Current status is trying to decide between the wood, metal, and hybrid designs I’ve made (curse you, trade-space demons!) and then designing a sled.

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In re reading this five whats? Meters, feet , inches …

Help me here plz.

Thank you

Five feet square, ala this:

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I’ve built the frame and put on the skirt. The bottom you see here is 2 parts. The top part is 1ft high and is designed to have the center cut out so the 5’x5’ piece would be the same height as the portrait 8’x4’. The math works where the chain length needed is shorter than the full sheet. My top bar is unistrut on top of a 2x4. The center 2x4s are flat and flush with the front of the frame to provide a wider surface to support the plyWood. I bought extra chain and added a foot to each side so I don’t have to worry about the chain running short. The second photo is my corner brace solution. I have plywood scrap and figured this wood stiffen the top corners plenty.

Hindsight: mount the motors before you hang it on the wall. The screws bolts are much easier to tighten at ground level vs. on the ladder!

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I’d defiantly build the frame to handle 5 Ft high material if I were working with a 5 x 5 - so a frame for 5ft x 8ft. I’d make 2 6inch shims to use with 4 x 8 sheet material to center it.

or in metric - if my base material is 1524mm x 1524mm then I would make a frame to accommodate 1524mm high sheets. So a frame for 1524 x 2439. I’d make 2 152 mm shims to center the work when using 1219 x 2439 sheets.

Thank you

Feets. The store what sells the nice Russian Birch sells it in 5x5’ size. I didn’t ax why.

It’s spelled metre in Canada for some reason.

I’m going to soldier on with a frame meant for 4x8’. I don’t expect to use the 5x5’ materials very often, and fot those times I’ll find a way to nest the profiles so I can rotate the sheet to the accuracy sweet spot.

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Any of the above, whatever measuring system meets your needs. I’d prefer the kus, but that would be a little big for a modern shop