I provide plans, patterns & kits for the i550 sailboat. The bottom hull panels utilize an entire 4’ x 8’ sheet of ply. Is it possible to make the physical size of the working area extend beyond the 4 x 8 to say 5 x 9 to support the router so it does not rock off the edge while cutting or using a drag knife?
It may be sufficient to add a ‘frame’ around the 4 x 8 area to support the router and prevent it tipping. Note that accuracy is variable across the working area, so be careful how you position any parts that need to have precise matching dimensions.
i am a complete noob so i have no idea myself
on makermade website they offer 15ft long chains
“A set of two, extra long (15ft) drive chains for the Maslow CNC. For those looking to improve their cut accuracy at the edges of their frame (by pairing with a 12ft top beam), or create a work surface larger than the standard 4 x 8 ft Maslow frame.”
hope this helps
The original maslow was based on a 10’ top beam (the motors were spaced roughly 10’ apart). To increase the effective work area because the top center and lower left and lower right corners became areas of inaccurate cuts, the common upgrade is to move the beam up from the recommended ~20" to 25"-36" from the work space and widen the motor spacing from 10’ to 12’ (like the pictures in this post - actually that whole thread is recommended reading), which requires the longer chain set (or a master link chain extension with additional 1/4" chain). Makermade sells longer chains and from my reading, the Metalmaslow kit also comes with the longer chains and at one point came with or maybe even still does come with a 12’ metal beam to extend the effective working area out. I own a makermade kit and highly modified sled a I have a metalmaslow sled. I find both to be of good quality. I saw some forum posts on a 14’ beam once, but I’m not sure if it actually got built or if it was only a concept. The best tool I’ve seen for analyzing working area size and motor spacing and beam height is the worksheet here. Play with that to get an idea of forces and sizing before building your frame. As far as cutting to the edge of the plywood sheet, when your sled is balanced, you can easily cut to the top edge and even the left and right sides without issue, though there is always that chance it will tip and ding your cut. The thing I have found with bordering the work space when I try cutting very small pieces, you must mind the gap and be careful about z offset. A smooth transition is needed so the sled doesn’t “walk the border” when it tries to go from one to the other. This seems intuitive to most and even while aware of it and trying to minimize it, it can be an issue, at least for me.
My sled on occasion will tip off the bottom when closer than 1/4" and this causes nicks and dings in what was a straight cut. I’ve been noticing though that when chains are extended with the sled located on the bottom half of the work area and not in the center, the more susceptible the sled is to “sticking” allowing the longer chain to go slack since the chains can’t push the sled. This is more of an issue with curved cuts when cutting toward the corner from the left into the right corner or from the right into the left corner. I’ve been wondering about a corner cable system that could put tension on the sled to “pull it into the lower corners” when needed, but this would likely be a huge pain to implement. I was considering instead of bricks, putting a pulley in the lower left and right corners and attaching the sled to clothesline cable using a hanging weight like many do with the chains to keep directional tension on the sled, but the tension would need to be changed depending on which corner it is closest to. It could be cool, but it isn’t a priority at the moment.
At times I cheat and guide the sled by hand in the corners or hold it flat on the edges to ensure I get full plywood use and it is accurate. I’ve considered paying my kids to be sled guides because I don’t have space in my shop for a larger beam on both sides of the frame (fireplace brick… not much I can do about that). Dealing with smaller pieces often does not require a full sheet, so rather than start cutting from the middle of the plywood, I mount the plywood offset to the left by 2 feet which allows me to cut the end of the plywood and then slide it over to cut the middle, discard the weed or rotate it 180 degrees and offset to cut the other end, so there are ways to be efficient, but if you are cutting full pieces, you will need a larger system.
I hope that is helpful. There are so many good discussions and an amazing amount of information on this forum.