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Just saw a CL posting for a small delta jointer.

It has a variable speed knob on it. Don't think I ever saw this as a feature before.

When would you ever get better performance from a jointer at a lower speed?
 

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What are the actual RPM ranges? Are they fast and faster, rather than slow and fast?

Depending on the setup, I suppose running at a lower speed may give you more torque for cutting harder material.
 

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Discussion Starter · #5 ·
@Rob
It is very precisely calibrated from "1" to "5". :)

Also, it is a knob rather than gearing/pully-size, so I don't think you get any mechanical advantage for more torque at lower speeds with this one
 

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If it's the 37-070 6" bench top jointer (I think it's also known as the JT160), the speed range is 6000 to 11000 RPM, and has two knives, so that makes it 12000 to 22000 cpm using a 5 position switch (6000, 7250, 8800, 9750 and 11000 rpm settings). It has a chart on the machine that shows recommend speed ranges for cutting various materials like plastic, soft/hard wood, etc..).

I don't have one.. just reading from the manual.

Cheers,
Brad
 

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That chart that Brad and the manual referenced regarding recommended speeds for different materials is helpful. If you cut plastic too fast, you can melt it. I suppose that would be as good a reason as any to slow it down.
 

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I had the jt160. The speed setting was continuously variable, not preset speeds. The only reason I would turn it down was if it was late at night, it was a bit quieter.
When it comes to machinery whether wood or metal the bigger the better is my rule of thumb. Variable speed?????? Sounds like a sales pitch. Higher RPM's I would think makes a better cut.
 

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With the exception of melting plastics I am in agreement the more times those knives are hitting the wood the finer the finish will be. Yet it will increase heat, and heat more than anything dulls sharp edges, so it may come with a price.

A comparison is a DeWalt 735 planer, which has a 2 speed gearbox, on a squirrel motor. The manufacturer says this about it. The two-speed gearbox allows the tool to deliver two speeds, 96 or 179 cuts per inch. You will use the 69 speed for creating dimension in the material while using the 179 speed for fine finishes. A lot of stationary 220 planers also have a 2 speed gearbox. I know I never change speeds on mine, and I've never known anyone who does on their planer. I'm just set on the faster speed. I do change depth of cut pretty frequently though, so maybe I do change speed, or workload, and never thought of it as such?
 

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It does still affect active cuts per minute. The idea of speed change = changes in cuts per minute was what I was talking about.

Plus that the idea of speed changes on a pretty much fixed speed tool isn't just one specific to this particular jointer. ShopSmith is another where all the tools had a vari speed motor to run them. Though they also had recommended ranges, a person could pick theirs if they thought it worked better. Vari speed isn't a new concept with this tool. I imagine there were others if you looked at every tool produced, where they necessary, probably not. Did their function make them "better" almost certainly not or they would have appeared more commonly.
 
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