Can't get moving, all cuts bad

Me and a buddy of mine are tying to start using maslow, but all of our cuts are off. At first when we were trying to cut out the sled, it was cutting Ovals instead of circles. After tuning the settings a bit, changing from a bottom to top fed with a counterweight system, and redoing the calibration a couple times, we got markedly better results.

However, now that we are cutting more complicated pieces, our errors are really starting to show. arcs look wonky, multiple pecks are cutting at different positions, lines aren’t straight as the sled rotates…

We tried doing cuts in two pecks (20in/min), full through cuts slower (15in/min, .8in), and shallow pecks faster (40in/min, .15in)…

Guess this is more of a rant. If I’m asking anything here its more things I should try troubleshooting (I think we’ve tried everything mentioned in the forms already), or advice on cutting parameters

1 Like

I tend to do 20-30 ipm at 0.15 depth with a 1/4-inch bit.

How well did calibration go? I’d run it again and see if you get improved accuracy on the second attempt.

1 Like

This suggests that the sled isn’t setup right. How well the sled is built is the most critical part of how well the cuts will be. If the router bit is off center from the ring, it’ll have issues.

1 Like

What should the tolerances look like on something like that? I can’t think of a way to easily measure that…

The distance from the top of the ring hole is about a 1/4" longer than that of the left and right (measured from below the sled), but our ring doesn’t perfectly center on those either

I ended up making a paper template. @bar confirmed the svg on the community garden for the sled holes is correct. I manually drilled my holes based on that template but the ring kit still didn’t align perfectly. I don’t know why. Ideally, when you grab the sled and rotate it with the router turned on and plunged into the board, the circle that’s been carved out doesn’t get any bigger (i.e., still a 1/4-inch hole with a 1/4-inch bit).

I’d like to see someone put a laser cut template (or sled) together… etsy or something… so that it can get made with high precision and have mounting holes for the various linkage kits and common routers already done.

Edit: meant to say sled and not template.

2 Likes

For those of us using the recommended rigid R22002 router, is there any sled template with the holes for the router mount centered with the holes for the ring mount? I wonder if having to eyeball the router mounting and centering is what is causing issues.

http://maslowcommunitygarden.org/Linkage-Kit-Sled-Templates.html

there are drawings with holes for the R22002 router with the two original linkage kits, but not with the ring. But you can use it and add it to the svg for the ring sled template.

Another issue can be if the sled doesn’t move smoothly across the surface (too much friction).

Here is a great hand build process for the sled…

Getting the spindle on the router dead center is key to cut accuracy. With the ring kit it is easy to check… Park the sled on top of a scrap that is at least the size of the sled. Turn on the router and send the bit about 1/10 inch into the material. Then, with the router still on, carefully rotate the the router. If the hole does not change shape, you are dead on. If you get a slightly out of round hole, you might be ok as long as the sled stays at the same angle most of the time. It you have a “C” shape or a hole that is twice as large as the bit, then make a new sled using the above hand process. You will solve a lot of problems.

Hang in there! Remember, this is supposed to be fun!

OK, so I read somewhere on here that the sled should balance if the ring is properly placed and “Adjusted”. Meaning that if the ring is not it the proper balance point for the weight the sled will not want to move smoothly. Also just to help the sled along I use an old candle and rub the wax on the bottom of the sled to help it slide more freely.

Sorry not the best pic.

There are two critical adjustments for the ring. One is making sure it is concentric with the router bit (meaning they share the same axis). One method is outlined in the above link.

Two is making sure you adjust the ring’s height from the sled surface so that it is parallel to the angle your sled is at when letting it free hang by picking it up by the chains. Once the ring is bolted down to the sled, you can use the large slots to raise or lower it from the sliding surface of the sled.

2 Likes

@Jayster My thinking is in line with what you are saying. I used the provided file to cut out my final sled and then agonized over precise placement of the router and ring. I also agonized over the chain distance from the tool. Based on my own experience and many comments on this board I felt these were the most crictical areas. Knock on wood my cuts have been spot on. I have also been running a feed rate of 15 ipm, plunge rate of 20 ipm, and a step down of .05. I am thinking of bumping that up but I think @broose_goose could possibly benefit from backing down a little bit. 0.356-0.375 per pass sounds like alot to me, especially at high feed rates. Then again I could be all wrong, this is my first go at CNC, and my cuts take a long time, but I am starting conservative and fine tuning from there.

I use a cut depth of .100" at 40 IPM (Inches Per Minute) and the machine runs great at those speeds. From my Metal CNC machine experience, as long as the tool is not Deflecting/Bending, and is not getting hot then it should be okay, and again as a rule if it sounds good it is good.

1 Like

When I was doing research on this earlier I read that the firmware is limited to 35.43 ipm (900mm). I guess that would mean you are running .1" at 35.43 ipm. I just cut out a piece at .15 and 15 ipm, worked well. In the maslow wiki on github it recommends .25 @ 20ipm for the single flute bit. I will prob try that in the near future.

https://github.com/MaslowCNC/Mechanics/wiki/Maslow-Store-0.25in-1-Flute-Bit

1 Like