Bob's CNC
Bob's CNC Evolution 4 Feeds & Speeds Calculator
Starting feeds and speeds for the Bob's CNC Evolution 4, with the numbers already adjusted for its spindle range and frame. Grab a starting point from the chart, then open the live calculator to watch the cut and fine-tune it for your exact bit.
Open the live calculator for the Bob's CNC Evolution 4Dialing in the Bob's CNC Evolution 4
Two things set the numbers on the Bob's CNC Evolution 4: how fast the DeWalt DW611 spins, and how much the frame can take without chattering. It runs a working range of about 10,000 to 30,000 RPM, on lead screw (acme threaded rod). The Bob's CNC Evolution 4 has a lighter frame, so shallow passes and patience beat trying to hog material in one go.
So for a 1/4" two-flute bit in softwood, a sensible starting point on the Bob's CNC Evolution 4 is around 17,000 RPM and 102 inches per minute, taking about 0.06875" per pass on a slot. The full chart below covers the materials you are most likely to cut. These are conservative starting points: always test on scrap and let your ears do the final tuning.
Bob's CNC Evolution 4 starting feeds and speeds
Two-flute bit, slotting cut (the toughest case for clearing chips). Feed in inches per minute, depth per pass in inches.
| Material | Bit | Spindle RPM | Feed rate | Depth / pass |
|---|---|---|---|---|
| Softwood | 1/8" | 25,000 | 100 ipm | 0.034" |
| 1/4" | 17,000 | 102 ipm | 0.069" | |
| Hardwood | 1/8" | 30,000 | 90 ipm | 0.017" |
| 1/4" | 20,000 | 100 ipm | 0.034" | |
| Plywood / MDF | 1/8" | 25,000 | 100 ipm | 0.034" |
| 1/4" | 17,000 | 102 ipm | 0.069" | |
| Acrylic | 1/8" | 25,000 | 100 ipm | 0.026" |
| 1/4" | 13,000 | 104 ipm | 0.052" | |
| HDPE / Plastics | 1/8" | 17,000 | 102 ipm | 0.026" |
| 1/4" | 10,000 | 100 ipm | 0.052" | |
| Aluminum | 1/8" | 30,000 | 60 ipm | 0.009" |
| 1/4" | 25,000 | 100 ipm | 0.017" |
Numbers are generated by our feeds and speeds calculator using the Bob's CNC Evolution 4's spindle range and a light-frame rigidity factor. Aluminum needs a single flute plus lubricant. Always confirm your bit maker's chart and test on scrap.
Want to see it cut?
Open the interactive calculator loaded with the Bob's CNC Evolution 4. Change your bit and material, watch the cut run live, and hear the difference between a dialed-in cut and a bad one.
Open the Bob's CNC Evolution 4 calculatorBob's CNC Evolution 4 feeds and speeds FAQ
What RPM should I run on a Bob's CNC Evolution 4?
For most wood with a 1/4" two-flute bit, 17,000 RPM is a good starting point on the Bob's CNC Evolution 4. Its working range is about 10,000 to 30,000 RPM. Go higher for smaller bits and finer detail, lower for big bits and heavy stock removal.
What feed rate should I use on a Bob's CNC Evolution 4 in hardwood?
Start around 100 inches per minute with a 1/4" two-flute bit in oak or maple on the Bob's CNC Evolution 4, at roughly 20,000 RPM. Listen to the cut and adjust: clean chips mean you are dialed in, fine dust means you are going too slow.
Can a Bob's CNC Evolution 4 cut aluminum?
Aluminum is a stretch for the Bob's CNC Evolution 4. Its frame is on the lighter side, so if you try it, use a single-flute bit, very shallow passes, lots of lubricant, and low expectations. It is happiest in wood and plastics.
Bob's CNC Evolution 4 full review
Specs, price, and what owners actually say.
CNC chip load chart
Feed-per-tooth for every bit and material.
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