Shaper speed?

[michael gates]

I have a 5hp shaper with a 5 3/4 raised panel bit and a powerfeeder running at 14 fpm. The cutter says 8500 rpm max and I have my shaper set to 8000rpm. What is the recommended speed? It bogs down a little, I think the belt is a little to loose as well.

[Rod Sheridan]

206079

Hi, the speed for your cutter is correct, about 12,000FPM.

How many cutting edges does your cutter have?

The loose belt is definetley a problem, correct that before anything else.

I've included a PDF of a spreadsheet I made for my shaper and feeder combination, you may want to do something similar or better.......Rod.

P.S. There's a definite relationship between cutter rotational speed, number of knives and feed speed as you can see from the spreadsheet. You'll always have to fine tune the process, however it's a start.

[jim mills]

Good info on the chart Rod, but do cutters come with the info needed to use the chart? ie. recomended cuts per inch & chip thickness.

[David Kumm]

Nice spread sheet Rod. Some shaper manuals have recommendations but they are more for liability reasons than actually helpful. I like full cuts and find I am almost always on the low speed end of the feeder. My feeders are 8 speed, more for the additional slow choices than to have eight. You will find as you use the shaper that you get a feel for the cut quality and the motor sound that helps get you in the ballpark. Any slowing of the cutterhead is a bad thing on a shaper so don't ever force it. Some belts are better than others in transmitting power as well. Dave

[Rod Sheridan]

Hi Jim, no they do not, that's an application issue.

I presume you have a two speed shaper with 8,000 and 10,00 RPM?

Step 1 is to select the speed to obtain correct tip speed in FPM (changes with cutter diameter obviously) For example you have a 6" cutter, you need about 12,000 FPM so you select 8,000 RPM on your shaper.

Step 2 is to determine feed speed, that's based upon chip thickness, say 0.008" to 0.012", or cuts per inch in the 100 range. (This is sometimes called Knifemarks per inch.

A 2 wing cutter will have a slower feed speed than a 3 wing cutter because of the required chip thickness. Hand feeding with a high number of knives can be a problem as you can't feed that fast.

So once you have spindle speed in RPM, the number of knives and the quality of surface finish determines feed speed. Too low a feed speed can result in burning, some wood species are more prone to this, so you have to increase feed speeds.

A good book to buy is The Spindle Molder Handbook, it's an English publication, heavy on safety to comply with the EU regulations, and theory. It's the most modern shaper book I've found and shows modern safe cutters and setup procedures.

The shaper is a great machine, i wouldn't be without one...............Rod.

[michael gates]

I tightened the belt this morning, the shaper is a five speed and my cuter is a 5 wing.

[Jerrimy Snook]

The chart is written for 2 and 3 wing cutters. It is a good starting point, however a 5 wing cutter will need to run at a slower rpm than a 3 wing. If you notice on the chart that if you had a 3 wing cutter at 8000 rpm and 14 ft/min feed, then you are cutting a .007" chip. At 3000 rpm the chip size almost triples. Try a lower rpm. I assume that the cutter is sharp.

[Jeff Monson]

Rod, thats a nice reference sheet. I've got it printed and ready to hang in the shop. Thanks!!

[Peter Quinn]

A 5Z cutter requires a pretty stiff feed rate to get the chip size correct, or you have to slow the spindle down and risk burning and kick back. I"m thinking a 2z or 3Z panel raiser may be more realistic choice for a small shaper. Loose belts are obviously a problem on any machine but particularly one as loaded as as a shaper raising panels, so do correct that and possibly replace that belt with a dogged version if possible. But also consider that a 5HP shaper may not drive a 5Z cutter very well in general. Think of it like a saw blade. More teeth equals more feed resistance. You would not attempt to rip 8/4 maple on a small table saw with an 80 tooth plywood blade, too many teeth. 5 wings may simply be too many teeth for the machine.

[Rod Sheridan]

I tightened the belt this morning, the shaper is a five speed and my cuter is a 5 wing.

Wow, that cutter requires a feed rate that your shaper probably cannot support.

Regards, Rod.

[Rod Sheridan]

Rod, thats a nice reference sheet. I've got it printed and ready to hang in the shop. Thanks!!

jeff, you're welcome..................Rod.

[J.R. Rutter]

I used to run some 5 knife Grizzly raised panel cutters on a 5 HP #27. But I had changed out the drive pulley on the motor to one that gave me something like 5500 rpm. Even though it is counter-intuitive, the motor had more torque capability with the larger drive pulley. The chip loading info is great (and invaluable to know when doing long runs to optimize cutter life), but for casual use higher knife marks/inch works out fine as long as the knives are sharp. They won't stay sharp for long runs though!

[David Kumm]

The cutter quality really makes a difference. While there is no need to spend more than necessary for many profiles, it makes sense to pop for Freeborn, Freud, or Schmidt unless going insert for cope and stick. I bought a set of Freeborn entry door cutters 15 years ago and use them for cabinet doors as well. 40 or 50 entry doors later and lots of cabinet doors in Hickory, Maple, Oak, Walnut etc they still don't need to be sharpened. Everytime I pull them out I think it is the last time and yet they still keep going. For some profiles it is better to pay for the quality of the carbide than the number of flutes. Dave

[michael gates]

I ran a lot of panels today. The cutter is doing a perfect job and after I tightened the belt it is taking everything in one pass and no longer bogging down.

I am cutting soft wood. No burning and a really nice cut, but I don't want to wear the bit out prematurely so do I need to slow it down under 8000rpm?

I am not getting chips, just really thin fluffy shavings.

[J.R. Rutter]

I am cutting soft wood. No burning and a really nice cut, but I don't want to wear the bit out prematurely so do I need to slow it down under 8000rpm?


Unless you will be running 1000's of feet, then you should be fine. Glad the belt tightening worked - easy solution!

[michael gates]

I usually make 2-10 doors per week.

[J.R. Rutter]

No worries then, IMO.

[David Kumm]

Michael, Let us know how those cutters hold up. I've always wondered as they are reasonably priced. Dave

[michael gates]

will do, but J.R can tell you better, It was reading his older posts that convinced me to get them in the first place other wise I would never have even considered a Grizzly cutter.

[ian maybury]

Thanks from here too guys, and to Rod for his list - a very informative discussion of the factors determining correct feeds and speeds. I've just fired up a Hammer F3 but have to do some careful studying of the 'Spindle Moulder Handbook (Eric Stephenson)' to do before going any further.

ian

[J.R. Rutter]

I am happy with the Grizzly 5-wing cutters that I still use. I have gone to either Freeborn or custom Misenheimer insert heads for panel and cope/stick profiles, but still use the brazed 5-wing for some door edge details that don't get run frequently. I will admit to running a pocket screwed oven trim face frame through where the edge profile caught the screw tips. The only result was a tiny nick and very faint lines on the finished part. As Rod demonstrated, these cutters can handle production feed rates if you have the power to support that. Only downside is limited profiles and extra sharpening cost when they do finally get dull.

[Jeffrey Choquette]

Unless you will be running 1000's of feet, then you should be fine. Glad the belt tightening worked - easy solution!

Thanks this helped me as well. I tightened the belt and my shaper stopped getting bogged down.

Jeff