Is that the tool chipload or the tooth chipload? If it is the tool chipload for a 2 flute cutter, then the feed is more like 30 inches per minute (~762 mm/min.) putting it well within the current range.
That is another alternative to approach. I think I know which video youāre referring to, and I thought about making full-depth cuts myself. I havenāt tried it on my machine yet. I know that required feed rate will decrease with the amount above the tool diameter you are going into your material. Depending on who you talk to, there are different āmaximumsā that you can feed into a material. Based on my experience, 2x the tool diameter is pretty safe. Iāve managed 3x before, but run into issues with vibrations and tool life. Itās possible that the feeds and speeds just needed to be optimized better. But, given the 2x diameter limitation, you would only be able to do full depth cuts into 1/2" ply with a 1/4" bit. Still, cutting 3/4" ply in two passes is certainly faster than cutting it in 3 or 4 passes.
The other question is how stable will the sled be cutting at that depth? If you canāt consistently maintain enough downforce on the sled, it will push the bit out of the work surface.
Just more testing that need to be done xD
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Iāve run both 2 flute upshear and downshear bits at those speeds (1000mm/min @10k rpm) and they both scream like a banshee. That chipload seems low to me.
Noob question, if a given bit performs ideally at 8000rpm and 1000 mm/min, say, why would that bit not perform equally well at 10000rpm and 1000 mm/min? What performance decline would one see?
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The goal here is to manage the machine into an as yet undetermined āsweet spotā, where weāre running as fast as we can while still being within tolerances.
@george, In your example there probably isnāt too much of a large difference, but by increasing rpm w/o increasing sled speed youāre decreasing tooth loading and machine loading.
I assume any of these work chip ābase numbersā require a quite rigid and beefy machine of a more traditional gantry design, as well as optimal work holding.
I only intended to point out that where these more traditional machines see āoptimal feeds and speedsā is far below Maslowās current observed capabilities. The places where Maslow can improve should be aiming towards those optimal numbers, and we should be attempting to collect data in those directions, for those goals.
I imagine weāll end up somewhere well below the āoptimalā speeds ultimately, but likely well above where the machine is now.
The router and the bits and the wood can take it, the open questions are increasing the speed of the Maslow apparatus itself.
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Thanks, this makes a lot of sense. Only other CNC Iāve used was a gantry-style Fagor thing that would kill you if you got in its way. Feeds and speeds were someone elseās job, I just made the design.
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@madgrizzle What if the "gravity were increased with bungies in the two lower corners of the frameā¦? or enclosed/tightened chain loops like a bicycle going from motor to sled to lower corner sprocket bearing and back to the motor? might help āpinā the maslow down for more aggressive carving action!
Just spitballing here. If my router wasnt so expensive and precious to me I would be donning the mad scientist lab coat and wrapping red danger tape around my workshop. one dayā¦ _
My spindle and the R22002 can both take 1/2" bits 
Clearly that means more expensive tooling, so everyone will have to make their own speed vs. cost trade-off; be it speed increase through tooling, spindles, gears, motors, or otherwise.
bungies in the corners only increase tension towards the corners, Gravity, as it relates to Maslow, is working between the work surface and the sled, and is a function of frame angle and weigh placement on the sled mostly.
ex: if your sled isnāt well seated on the work surface (if its ātippyā):
- decrease the verticality of your frame,
- lower the center of gravity on the sled (everyone should be doing that already)
- increase weight of the sled while attempting to maintain the center of gravity as low and centered as possible.
At some point in the process above, sled weight gets high enough that friction of sled/work surface increases too much, or sled weight increases to a point where the motors cannot lift it, but until then you are increasing the force of gravity on the sled/workface interface.
While this is true, Iāve hesitated to go to 1/2" bits with the Maslow because they tend to have even higher required chiploads.
According to the Onsrud chip load tables, a 2 flute 1/2" downshear bit would need 0.007. At 10k rpm, we would have a required feedrate of 3556 mm/min, which is way beyond the Maslowās capabilities. This is with a 1/2" deep cut. At 3/4" depth of cut, weāre only reducing the speed 25%, or to 2667 mm/min.
As a point of comparison, a 2 flute 1/4" downshear bit needs 0.005. At 10k rpm, thatās 2540 mm/min required feed rate at 1/4" depth of cut. If we were to increase the depth of cut to 1/2", or 2x the tool diameter, again we reduce speed by 25%, which brings us to 1905 mm/min. If we were to try to push the tool to 3x itās tool diameter, we reduce speed by 50%, which brings us to 1270 mm/min.
To summarize, a 1/4" bit, when pushed to 2x itās tool diameter, stands within the theoretical top speed of the machine with the larger sprockets. With a 1/2" bit, you would need to be going an order of magnitude faster, which probably means you would have to use a combination of larger sprockets and more powerful X-Y axis motors. As @madgrizzle pointed out, the machine also may not be stable at those speeds.
As a big disclaimer, these numbers are only suggested feed rates and if you can get a 1/2" bit to cut well with speeds of the stock Maslow, then I stand corrected. There can be quite a difference between the theory Iām discussing here and reality. However, I use these numbers on a daily basis in a production environment and they work pretty well as a starting point. Usually, I find that I can push my tooling harder than the āminimumā feed rate I get from these calculations.
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- change the mounting of your chains to the sled
if you hang the sled in mid-air by the chains, it should stay stright, or tip
the top very slightly towards the sled side. If it tips away from the sled at
the top, (or if it tips a lot in either direction) adjust the distance from the
sled to the chains.
Itās important to realize that these feedrates are aiming for production use
(the fastest cutting possible, without wearing out the bits so much that you
loose more time changing bits than you save from cutting faster)
they are a starting point. You can generally cut significantly faster if you are
willing to wear out the bit sooner, or a fair bit slower if you are willing to
take more time (eventually you get so slow that you start having heat issues)
IIRC the rule of thumb is that if you are within a factor of 2 (half to twice
the suggested feedrate) you are probably in fairly good shape.
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Agreed on #4 this will change the sledās favored orientation, but the chains should be kept Parallel to the workpiece.
While directly related to Sled CoG. Chain Parallel-ism (new term!) is assumed to exist and that one wouldnāt yet want to change that (to be out of parallel, and exercising some āretainingā torque on the sled) if there are other options still on the table.
My main point is that successful increase of the feed rate of the machine is going to require among other things, the most stable sled configuration we can establish.
I agree with this, but the priority needs to be First, balance the sled on the
chains and only after that do you look at chain parallelism and change the frame
if it is too far off.
everyone has that thought, but itās far more complex than you think.
the chains on the two sides would not be the same length, so you canāt just loop
it, you need separate motors
the chains can only pull up to so much of an angle, so the entire machine would
need to be about a foot taller to give the bottom motors room
you would roughly double the cost of the maslow (twice as much chane, motors,
wiring, mounts)
and it would add more complexity to the software
but it would be done.
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25T gears are in! Unfortunately, I start a brand new position with a new company on Monday, so I expect even further delays completing my Maslow. 
@MeticulousMaynard What are your thoughts on this bit? I had planned on testing it with my machine for months now but I donāt like to keep waiting. If I send you one, would you be willing to give it a go and report back? The single flute brings the RPM down and the cut length would support full depth cutting at risk of tool deflection, so itās a whole new world of uncharted experimentation! 
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I completely empathize with that. Iām going to have to start job-hunting soon myself. I feel like thereās always something more to do before I can get to the stuff I want to do.
It certainly is closer to the Maslowās feed rates than a 2 flute compression bit, even of the same diameter. With a compression bit, you really want do a full depth cut to take advantage of the flute geometry. Itās certainly worth trying and seeing if it holds up to those kind of loads. Iām getting about 1800 mm/min @ 10k rpm as a starting point, so it may need to be paired that with the 25T sprockets.
I canāt promise Iāll be quick about it, but Iād be willing to give it a shot. My Maslow is still buried right now in the new shop. 
Iām going to need to get at it sooner rather than later, but unfortunately I still have a myriad of tasks I need to get done before I can get to the Maslow. Along my current timeline, it should be back online around mid-May.
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Life gets in the way of Living.
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So has anyone managed to test with larger sprockets and gotten a faster feed rate working?
we know that the current motors with the current sprockets run out of power at
the top of the workpiece, larger sprockets will make this worse. So you would
need more powerful motors, which would require a more powerful motor controller.
David Lang
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