Welcome to the forum. This may help.
Are you also using V-bits for your signs? I cut almost everything at 18k rpm with 1/4" upcut/downcut/compression bits at 175ipm in Walnut, Maple, Cherry, etc, and a depth of cut of about 0.300". With 1/8" bits I am fairly conservative cutting at 75ipm to 100ipm. V-bits range from 75ipm to 150ipm.I am trying to cut signs on poplar and hard maple with straight dual full and spiral up cut bits, can anyone recommend bit and feed speeds.
It is a Sainsmart 3018Pro with a Geminstu spindle.
What would you suggest for 1/8" straight cut on softer woods like poplar.Are you also using V-bits for your signs? I cut almost everything at 18k rpm with 1/4" upcut/downcut/compression bits at 175ipm in Walnut, Maple, Cherry, etc, and a depth of cut of about 0.300". With 1/8" bits I am fairly conservative cutting at 75ipm to 100ipm. V-bits range from 75ipm to 150ipm.
Your machine isn't as rigid as mine so these feedrates are too high but you can cut them in half and see how that works out. Some folks have bigger and more powerful machines than mine and cut twice as fast as I do, so it just depends on how flexible your machine is to determine good feed rates.
How many flutes on your bit? More than two will be an issue, especially in softer woods. Some Poplar is pretty hard, btw. I would start with 50ipm and see how that does, depth of cut about 0.050", maybe up to 0.075".What would you suggest for 1/8" straight cut on softer woods like poplar.
What about rpm of the bitOn light machines it's usually best to make your cutting depth no more than half the diameter of you bit. If you find your machine flexing then cut the original depth in half and use a faster cutting speed. I usually run 1/8" bits at 75 to 100 ipm depending on the wood.
I'm using a Sainsmart 3018 hobby router, so I'll run a slower speed.I usually run between 18k to 24K when doing wood, and 12K to 15K when cutting aluminum (30 to 60 ipm), however I'm also running 2.2Kw water cooled spindles.