09-10-2015, 09:40 AM
It's been almost a year. Winter set in, the garage got cold and I said goodnight to the crew.
Okay, spring came and the planer got hired. I used the shaper to make a few tee-nuts for it. Six weeks steady on the planer over the last couple of months has shown me that HSS shaper/planer tooling is a leetle different than lathe tooling. Top rake being slightly negative has a big impact on longevity - we don't want the very tip striking first, but would rather use a downward slicing effect rather than lifting. Too much of that and the heavy chip is directed against the work, scratching it.
Might be easier to visualize by considering a lathe. Looking at the tool tip while on center to the work, you'll notice that the top slopes back and downward towards the operator and to the right. With a shaper/planer, that slope goes UP. And there is some serious side rake, like 35 degrees.
Might be interesting to point out that this is the natural way a bit will go when stoned up sharp as work progresses. The tendency is to stone the top of the dull tip rather than the entire edge. One good reason zero rake tool holders are better - the rake is nearly perfect and just gets better in use. Lathe holders need the tool tip knocked down almost level from the get go.
Tooling 101.
Okay, spring came and the planer got hired. I used the shaper to make a few tee-nuts for it. Six weeks steady on the planer over the last couple of months has shown me that HSS shaper/planer tooling is a leetle different than lathe tooling. Top rake being slightly negative has a big impact on longevity - we don't want the very tip striking first, but would rather use a downward slicing effect rather than lifting. Too much of that and the heavy chip is directed against the work, scratching it.
Might be easier to visualize by considering a lathe. Looking at the tool tip while on center to the work, you'll notice that the top slopes back and downward towards the operator and to the right. With a shaper/planer, that slope goes UP. And there is some serious side rake, like 35 degrees.
Might be interesting to point out that this is the natural way a bit will go when stoned up sharp as work progresses. The tendency is to stone the top of the dull tip rather than the entire edge. One good reason zero rake tool holders are better - the rake is nearly perfect and just gets better in use. Lathe holders need the tool tip knocked down almost level from the get go.
Tooling 101.