Shaper speeds?

[dwacker]

As you said all the cuts are fake (at least you owned up to it). 

 

Its not about owning up to anything. Its about the hyperbole importance of HP vs knowledge of your machinery and cutter. Ive been doing this professionally for Id say 29 maybe 30 years now and never heard a machine operator say wait a minute I need to go calculate required HP.  Its not going to happen in this industry period. 

This a hobby forum when it comes to HP most if any really need to care. Even in the professional woodworking industry unless your designing machinery you never need to care, you buy machines that are made for the task at hand based on the specs and leave the physics to the machine makers.

When you buy a machine that is underpowered you either take lighter pass or you fine tune your cutters and your not going to do the latter without the knowledge period regardless of your available HP.

Its not rocket science nor is it anything like machining metal. Its very simple math that anyone can do with a pocket calculator or a piece of paper, some can do it in their heads. Your never going to see any gains if all you are is a feed monkey and just shove wood across a cutter and hope for the best then live with the result.

 

 

Some of this stuff is just basic apprentice type experience but even the more somewhat high-tech stuff like mouldings there is no reason what so ever to delve into mathematical hp calculation unless your an arm chair woodworker or machine designer.

[Dan S]

The 1.5 hp shaper is rated at the motor not the spindle. It has a lot more torque available through the pulleys and or gearing than a router. That is why you can run larger dia cutters.

The bike issue is the same your trying to produce a certain amount of work and when the torque required to go up hill increases you have to change the gear ratio to produce it

The pullies on shapers usually reduce the torque available, from the motor.

take this shaper for example. http://www.grizzly.com/products/1-1-2-HP-Shaper/G1035

it has 2 settings according to specs (i've never run this machine personally) 7,000 rpm, and 10,000 rpm, however it's only got a 3450 rpm motor. Thus it's gear ratios are 1:2.02 and 1:2.89 respectively. So you have basically half and 1/3 the torque of the motor at the spindle.

I assume what you mean is that the shaper motor is always running at it's optimum output rpm, reguarless of spindle rpm and cutter diameter?

[dwacker]

This is because the max tooling diaper is so small on small shapers. Add to much torque and you start breaking off small spindles. When you start getting into machines that can run 6000 and lower rpm the pulley steps go the same as the smaller machines until you get to 6000 rpm then they go the other direction increasing torque.

[Dan S]

Ive been doing this professionally for Id say 29 maybe 30 years now and never heard a machine operator say wait a minute I need to go calculate required HP.

Yes, most likely because someone either told them what to do, or they learned what could be done safety at some point. The other likely scenario, is because they looked it up on some spec sheet or reference quide provided by the manufacture, that was created by an engineer.

 

This a hobby forum when it comes to HP most if any really need to care. Even in the professional woodworking industry unless your designing machinery you never need to care, you buy machines that are made for the task at hand based on the specs and leave the physics to the machine makers.

Even if someone doesn't need to know it, it doesn't harm them to have some level of appreciation of it.

[Dan S]

Let me ask this - how many passes would that joint take on a traditional router table?  Keep in mind he was ganging cutting boards for a dozen or more boxes.  Certainly more than two passes.  So yes, he stalled the machine, but it was still ridiculously faster than making the same joint on a router table.

I'd still gang mill them, but instead of 1 pass with 4 slot cutters, I'd probably do 4 passes with 1 cutter, or 2 passes with 2 cutters. I'd make up some of the time lost from multiple passes, by feeding faster. it's all a trade off.

[dwacker]

That cut with that cutter setup on a shaper is 22.5 FPM 2 two or three passes due to its size. Takes less time to take three passes than it takes to take one with the machine slowing down. The accuracy of the multiple cutters and spacers is just another bonus of not having to move the fence.