Shaper speed & feed rate

[joe milana]

While reading about cutter speed, diameter, and feed rate, info seems to be all over the board.

Current literature suggests 10,000fpm as a minimum cutter speed for carbide on hardwood. This would mean that 10,000rpm would be the minimum for a 4" cutter. As fast as most shapers spin. This would mean that smaller cutters would need much more RPM. :confused:

Freeborn tool suggests 17-19 knife marks per inch as a starting point for their cutters. If that's the case, and my math is correct, with a 4" cutter at 10,000rpm, I need a feed rate of about 42 fpm. A 6" panel raiser would need 8,000rpm and about 33 fpm. Just doesn't seem right & a bit out of my comfort range.

Maybe I need more coffee before shaping, or maybe I should quit reading and keep doing what works for me.

[Rod Sheridan]

228373

Hi, obviously cutter speeds depend upon diameter, cutter material and the material being cut.

You're correct in that most shapers can't spin small cutters fast enough to achieve tip speeds in the 8,000 to 14,000 FPM.

I normally run around 50 knife marks per inch.

I've included a chart I made for my shaper.........Rod.

[J.R. Rutter]

Like Rod says, running higher knife marks per inch is better for most of us. I took some time to do a quick excel sheet to satisfy my own curiosity this morning. I combined info from Carbide Specialties (Thanks, Tom), my SCM shaper manual, and Freeborn Tool. I plugged in what I thought was my typical setting for raised panels and it falls within all of the recommended parameters, so I guess I knew what I was doing :-)

https://lh6.googleusercontent.com/-nQiCCYk_L1g/T3dVe6Y_UUI/AAAAAAAABzM/epbOVXMOp-Y/s576/Shaper%2520snapshot.jpg

[Jeff Duncan]

The guys have some good info there.....I just go by feel. As a for instance, if I'm running some parts with a certain cutter, certain spindle speed, and taking off 1/2" of material in hard maple, I'm not running the same speed as if I'm using the same cutter at the same speed taking off 1/16" of maple. One of those things I'm still learning, but it comes pretty naturally.

good luck,
jeffD

[joe milana]

Thanks Rod. Your spreadsheet confirms the notion that smaller cutters don't spin fast enough, but people make them work just fine. 50 cpi is a lot higher than Freeborn's recommendation of 18-19 & leaves a lot of room for speeding up the feed rate.


JR, even @ 25cpi, seems you could speed your feed rate a bit to get closer to Freeborn's recommendation.

I guess the point I'm trying to make is that I have been feeding too slowly, I don't get burning, but fear shortening cutter life. I feel like I should try speeding up feed rate until I get a poor result, then back off until I get a good finish. Maybe the difference between 19 & 25, or 25 & 50 cpi isn't as significant as it looks on paper.

Jeff, I understand your "feel" concept. It's kinda like the difference between edge jointing a 3/4" board, and face jointing a 6" board.

[J.R. Rutter]

JR, even @ 25cpi, seems you could speed your feed rate a bit to get closer to Freeborn's recommendation.

Maybe the difference between 19 & 25, or 25 & 50 cpi isn't as significant as it looks on paper.

My little experiment was to find out how these various rules of thumb stacked up together. Freeborn's recommendation seems to be rooted in the steel knife rule of thumb where maintaining adequate chip load is more important for cooling. Thicker chips carry away more heat. Not that this isn't important for carbide or alloy tips as well, but certainly less critical. I do know that moulders are commonly run at around 20-25 FPM (and often slower) with heads spinning at 6,000 RPM, unless they are jointed so that all knives are providing a finish cut, then speeds can triple.

[joe milana]

JR, according to your spread sheet above, how do you calculate chip load? I'm assuming it's 1" / 25cpi. If so, I get .040.

[Stephen Cherry]

This is all pretty interesting from a theoretical standpoint; interesting reading.

I think that there are a few more issues. I am absolutely not a cutting tool expert.

First- cuts per inch produce a less "scalloped" effect as the cutter diameter increases.

Second- the chip load, as I understand it would be the thickness of the cut for material heading into the spindle centerline at a given feed rate. As the material is cut further from the centerline, the chip thickness would decrease due to the curvature of the cutterhead. (at the tip, the cutter cuts at a big skew from the feed direction, at the very tip, the cutter cuts parallel to the feed). All adding up to a thinner chip for a large diameter cutter.

Also, given recomended cutter speeds and feed rates, you need a machine with the hp to support this. THis is probably the reason that real production shapers have big hp compared to my little 3 and 5 hp machines.

Finally, for me, I just run my shaper the same way I do a handplane. Eyes, ears, touch. Hopefully not smell. If the surface feels good, and the chip looks like a little shaving (not dust), then it is working fine.

[joe milana]

This is all pretty interesting from a theoretical standpoint; interesting reading.

I think that there are a few more issues. I am absolutely not a cutting tool expert.

First- cuts per inch produce a less "scalloped" effect as the cutter diameter increases.

Second- the chip load, as I understand it would be the thickness of the cut for material heading into the spindle centerline at a given feed rate. As the material is cut further from the centerline, the chip thickness would decrease due to the curvature of the cutterhead. (at the tip, the cutter cuts at a big skew from the feed direction, at the very tip, the cutter cuts parallel to the feed). All adding up to a thinner chip for a large diameter cutter.

Also, given recomended cutter speeds and feed rates, you need a machine with the hp to support this. THis is probably the reason that real production shapers have big hp compared to my little 3 and 5 hp machines.

Finally, for me, I just run my shaper the same way I do a handplane. Eyes, ears, touch. Hopefully not smell. If the surface feels good, and the chip looks like a little shaving (not dust), then it is working fine.

I'll agree the numbers seem a bit theoretical, but I would like to at least believe I'm getting maximum cutter life. It would be nice if cutters came with instructions:
Recommended RPM: xxxxx
Recommended feed speed for hardwoods: xxfpm
Recommended feed speed for softwoods: xxfpm
But they don't.

[J.R. Rutter]

JR, according to your spread sheet above, how do you calculate chip load? I'm assuming it's 1" / 25cpi. If so, I get .040.

You need to account for each wing, even though the finish cut is assumed to be from a single wing due to spindle and cutter tolerances.

http://www.carbidespecialties.com/cutter_performance_specs.htm

[Rod Sheridan]

JR, according to your spread sheet above, how do you calculate chip load? I'm assuming it's 1" / 25cpi. If so, I get .040.

Hi JR's post had an error in it.

Knife marks per inch = RPM X wings/feed rate 7500 X 3/ 25FPM/12 = 75 knife marks per inch. (JR forgot the number of wings).

Chip thickness = cuts per minute/feed rate 22,500/25FPM/12 = 0.01333"

Cuts per minute of course are RPM X # of cutters 7,500 RPM X 3 = 22,500 cuts per minute.

The usual error is feeding too slowly, hence you need a feeder

For curiosity sake I suggest you perform the above calculations on your planer to give you some numbers that will relate to work you see on a routine basis.........Rod.

[Stephen Cherry]

I'll agree the numbers seem a bit theoretical, but I would like to at least believe I'm getting maximum cutter life. It would be nice if cutters came with instructions:
Recommended RPM: xxxxx
Recommended feed speed for hardwoods: xxfpm
Recommended feed speed for softwoods: xxfpm
But they don't.

Joe, I agree- recomended rpm, and feedrates, at least a starting point, would be a big plus. But what is best for the cutter probably is not best for your wood product.

[joe milana]

Ahh...Good stuff! ...And WAY better than a bandsaw thread! :D It's interesting that the information on the carbide specialties (good stuff) doesn't give rim speed recommendations, but my shaper manual does. Seems all calculations start with RPM, which is selected using rim speed.

[J.R. Rutter]

Hi JR's post had an error in it.

Knife marks per inch = RPM X wings/feed rate 7500 X 3/ 25FPM/12 = 75 knife marks per inch. (JR forgot the number of wings).


I thought I made an error once, but I was mistaken. :-)

Only one knife or wing is giving the finish cut (knife mark). That is why the formula for knife marks assumes one cut per rotation. Unless you are running a very high end hydrolock or solid spindle/body HSK type tool, the tolerance that allows the removable cutter to slip onto the spindle (both to run it and to sharpen it) means that one wing is inevitably projecting further from the center of the spindle than the others. But each knife is generating a chip, so that is when you take it into account.

[joe milana]

I thought I made an error once, but I was mistaken. :-)

Only one knife or wing is giving the finish cut (knife mark). That is why the formula for knife marks assumes one cut per rotation. Unless you are running a very high end hydrolock or solid spindle/body HSK type tool, the tolerance that allows the removable cutter to slip onto the spindle (both to run it and to sharpen it) means that one wing is inevitably projecting further from the center of the spindle than the others. But each knife is generating a chip, so that is when you take it into account.

So are you saying your above formula (in post #3) is or isn't correct?

[J.R. Rutter]

Well, it is correct as far as I understand things. I did see that Rod's chart took all 3 wings into account, but the industry standard is to just use one.

[Rod Sheridan]

Well, it is correct as far as I understand things. I did see that Rod's chart took all 3 wings into account, but the industry standard is to just use one.

J.R., that's interesting, I was taught to use all knives in the calculation................I'll have to check back in my reference materials.....Regards, Rod.

[joe milana]

Well, it is correct as far as I understand things. I did see that Rod's chart took all 3 wings into account, but the industry standard is to just use one.

Got it. It seems Chip load is the more relevant number anyway.

[joe milana]

OK Rod, According to your chart, If I'm using a 4" 3 wing carbide door edge profile bit, I should spin it at 10,000rpm to get 10,467 FPM cutter speed, and that's on the lower end of the cutter speed scale. With a feed speed of 37.7FPM, my chip load is 0.019, which is good, but that's too fast a feed speed for me. If I slow my feed speed down to 24.6, My chip load gets a bit light, and the CPI gets pretty high. (By the way, the chip thickness for 6K & 10K 3 wing cutters seems to be missing on your chart).

If I slow the shaper down to 8000rpm, I'm below the recommended rim speed, but I just tried it hand feeding & it cuts like butter & leaves a smooth finish. With this RPM, I can get my feed speed more manageable, and still get a good chip load. Suggestions?

[J.R. Rutter]

J.R., that's interesting, I was taught to use all knives in the calculation................I'll have to check back in my reference materials.....Regards, Rod.

I guess that the tighter the tolerances, the more relevant it becomes to factor in all of the wings. A high precision jointed moulder will run at >70 FPM with excellent results because all knives are finish knives. It may well be that with good quality tooling and machinery, the reality lies somewhere between a 1 knife finish and all knives finishing. But a vibration prone machine with bushed cutters will never get there.

[Rod Sheridan]

Joe, why is the feed speed too high, lack of power?

At 8,000 RPM, you can of course reduce your feed speed.

You are finding out why higher number of knives is the reverse of what you need for hand fed operations.

If you have the opportunity to try out a 2 knife HSS Euro block cutter, you'll be very pleased, as they hand feed even better.

Don't drop your speed too low as you'll have a greatly increased risk of kickback.

Remember that above calculations are guidelines, aside from the safety issues, you can adjust feed speeds to match your hand feeding abilities.

Have you done the calculations for your planer as an item of interest?

Regards, Rod.

[joe milana]

Joe, why is the feed speed too high, lack of power?

At 8,000 RPM, you can of course reduce your feed speed.

You are finding out why higher number of knives is the reverse of what you need for hand fed operations.

If you have the opportunity to try out a 2 knife HSS Euro block cutter, you'll be very pleased, as they hand feed even better.

Don't drop your speed too low as you'll have a greatly increased risk of kickback.

Remember that above calculations are guidelines, aside from the safety issues, you can adjust feed speeds to match your hand feeding abilities.

Have you done the calculations for your planer as an item of interest?

Regards, Rod.

Rod, the feed speed just seems too fast for me. I have plenty of power (9hp) & an 8 speed feeder. I can barely get to the other end of the shaper to catch the part. :eek:Well....that may be a bit of an exaggeration...
I don't have a euro block cutter yet, but have been looking for one. I can see the benefit of having a two wing cutter & slower feed speed.
I haven't run the calculations for the planer yet because I have a byrd head, and I can't remember how many rows of cutters it has. :confused: It's 5 or 7. I'll have to pull the cover & see.

Thanks everyone for the comments. I have definitely been feeding & spinning cutters too slowly. Now I have some numbers to shoot for & hopefully will see some better results. That's some good reading on the carbide specialties website. Carbide processors has some interesting reading as well.

[Jeff Duncan]

Joe, I think your last post hit the nail on the head....even if you get all your calculations correct, if it turns out the work is being fed faster than you can handle it then your back to start again!

I believe calculations are much more important when your in the shoes of a molder operator who is running thousands of bd. ft. of the same wood and profile all day long. In that situation you want to optimize as many aspects of your operation as possible. I'm on the opposite end of the spectrum running small batches of all different species, shapes, and cut depths. I run some stock as slow as 6.5 fpm....(not very often, but it has come in handy the couple times I've needed it). The majority of my stock goes through between 13 and 22 fpm with a spindle speed of somewhere in the neighborhood of 8k rpm's. There are quite often times I can feed faster, but the next bump up is 43 fpm without changing the gears, (which is a PITA and would likely take longer than just running the stock at the slower feed rate), which is quicker than I feel comfortable with getting the stock lined up into the feeder and then running to catch at the other end. Maybe when I get another employee I'll bump up the speed;)

The heads I use most are my corrugated heads, and a couple of the 2 HSS knife blocks mentioned earlier. They're the most flexible for my needs and the 2 knife finish on both of them is really outstanding....certainly better than carbide when sharp.

good luck,
jeffD

[Tony Joyce]

A high precision jointed moulder will run at >70 FPM with excellent results because all knives are finish knives.

A high precision jointed moulder will run feedrates 200 ft. per minute up to 3000 ft. per minute. (As per Weinig website)

[Jeff Duncan]

A high precision jointed moulder will run feedrates 200 ft. per minute up to 3000 ft. per minute. (As per Weinig website)


Your guys are going to have to drink a lot of coffee to keep up with 200 fpm:D

At 3000 fpm boards are going to be shooting out at about 34 mph.....I don't know anyone who's gonna voluntarily catch those:eek:

JeffD

[Tony Joyce]

Your guys are going to have to drink a lot of coffee to keep up with 200 fpm:D

At 3000 fpm boards are going to be shooting out at about 34 mph.....I don't know anyone who's gonna voluntarily catch those:eek:

JeffD

My machine only runs a modest 60FPM max but, I usually run it at 25-30FPM. At those speeds(200+), outfeed conveyers are a must. The salesman that sold me my current moulder, said they had 4- 200FPM machines in a plant running MDF mouldings 16hrs a day. That's a lot of mouldings, good thing they were next door to the MDF manufacturing plant!

[joe milana]

My machine only runs a modest 60FPM max but, I usually run it at 25-30FPM. At those speeds(200+), outfeed conveyers are a must. The salesman that sold me my current moulder, said they had 4- 200FPM machines in a plant running MDF mouldings 16hrs a day. That's a lot of mouldings, good thing they were next door to the MDF manufacturing plant!

MDF moldings... 200fpm... 16 hrs a day...Kinda takes the romance out of woodworking, but I bet it would be impressive to see. :eek:

[joe milana]

Joe, I think your last post hit the nail on the head....even if you get all your calculations correct, if it turns out the work is being fed faster than you can handle it then your back to start again!

I believe calculations are much more important when your in the shoes of a molder operator who is running thousands of bd. ft. of the same wood and profile all day long. In that situation you want to optimize as many aspects of your operation as possible. I'm on the opposite end of the spectrum running small batches of all different species, shapes, and cut depths. I run some stock as slow as 6.5 fpm....(not very often, but it has come in handy the couple times I've needed it). The majority of my stock goes through between 13 and 22 fpm with a spindle speed of somewhere in the neighborhood of 8k rpm's. There are quite often times I can feed faster, but the next bump up is 43 fpm without changing the gears, (which is a PITA and would likely take longer than just running the stock at the slower feed rate), which is quicker than I feel comfortable with getting the stock lined up into the feeder and then running to catch at the other end. Maybe when I get another employee I'll bump up the speed;)

The heads I use most are my corrugated heads, and a couple of the 2 HSS knife blocks mentioned earlier. They're the most flexible for my needs and the 2 knife finish on both of them is really outstanding....certainly better than carbide when sharp.

good luck,
jeffD


Jeff, can you give me a couple recommendations for a corrugated head? I see Laguna has the Garniga, but not sure I want to deal with them. Also, If I get a euro block as well, I would assume steel is the way to go, as opposed to the aluminum ones. Thanks!
Oh, and one other thing, do you have an opinion on the HSS stile & rail cutters for the euro block? Do you think the knives would make it through the average kitchen project before needing sharpening?

[Jeff Duncan]

Joe, I have 2 of the Euro blocks, one aluminum and one steel and they both work fine. My preference would always be the steel though as in my head I think the mass helps, as well as will hold up better long term. Whether or not that bears out in reality??? The steel head was made by FS Tool and I believe they still carry knives. The aluminum was made....or at least sold by Freud, and I don't think they support the knives any longer. I think Amana also made knives for these heads though don't take my word on that one? One place I do like the aluminum is on my little 3 hp shaper, seems like it's probably a bit easier for it to spin on the little guy.

The knives will last easily several kitchens worth of doors....though I use Freeborn carbide cutter sets for that myself. I do use HSS corrugated knives for my interior doors as they're a custom profile I had ground. I've done many, many dozens of doors using the same set I had ground about 6 years or so ago. Most of the doors are hard maple and rift white oak with the occasional cherry set. In that time I've had the set sharpened once and it's probably getting close to time for either another sharpening, or replacement. The catch with HSS knives for doors is that they can only be sharpened a couple times before the profiles get sloppy.

If you do a LOT of cabinet or entry doors you'll want to look at real insert tooling, but it's a fairly steep entry fee!!!

For me there are 2 real advantages to the Euro block, first is the off-the-shelf knives are very cheap compared to just about anything else out there. Second is it's very easy to customize knives. I have 2 sets each with a fair amount of profiles. If I find something close to what I want I can grind it to exactly what I need. The steel is a bit thinner than what I use for the corrugated head so it's easier to grind! The only real downside is the profile height limitation....and that's where the corrugated heads come in!!!

For corrugated heads I go with Schmidt, they are really the standard for these heads and the prices are pretty reasonable. If you don't have a supplier already 2 places I like to deal with are Connecticut Saw, and Ballew Saw & Tool. Both places are very helpful and can steer you in the right direction. Connecticut Saw can also do your custom profiles for you if you don't have a local place...not sure about Ballew?

For someone just starting out I'd try to find a deal on a gently used Euro block set. I've had 3 of these sets and each one was bought with a shaper. I do see them pop up on e-bay from time to time. For a corrugated head I'd probably start out with a 2" and buy larger ones as needed. I have up to a 5" tall head though I've not yet come up with a need for it yet! I do use the 4" head fairly frequently though but the knives in it are only about 3" tall. If you do a lot of shaper work you'll likely find yourself wanting to acquire more and more heads so you don't have to change out your most often used profiles;)

hope this helps....
JeffD

[joe milana]

Huge help Jeff, thanks! Ballew is in Springfield (only 180 miles away), and I do get down that way often. Checked out the Schmidt website. Looks like I can get into a corrugated head pretty reasonably.

[Larry Edgerton]

I guess that the tighter the tolerances, the more relevant it becomes to factor in all of the wings. A high precision jointed moulder will run at >70 FPM with excellent results because all knives are finish knives. It may well be that with good quality tooling and machinery, the reality lies somewhere between a 1 knife finish and all knives finishing. But a vibration prone machine with bushed cutters will never get there.

I have always figured that this is why the Tersa heads do such a nice job, that being that all the knives are in the cut equally. I hadn't thought about that with a brazed shaper cutter. I assumed that my insert cutters were off.

At one point I was thinking about buying a moulder. I went to the Grand Rapids show and looked around.

They had one turret machine there that could do 300 mouldings profiles without changing a cutter, ran at 370 FPM, came with a stack feeder and catcher, and was $2.5M.

Not what I wanted to do for a living. I only like making the first one of anything, standing and watching a machine all day is not what I signed up for. Wish I didn't like doing odd projects, I'd have more money.

I always do a quick calculation in my head, but for the most part I am in Jeffs camp. Sound is the final decider. If it doesn't sound right I make changes. But how does one explain that?

Larry

[J.R. Rutter]

My machine only runs a modest 60FPM max but, I usually run it at 25-30FPM.

Ditto for me - I knew that high speed moulders ran fast, but I never would have guessed 1000s of feet per min!

[Tony Joyce]

Ditto for me - I knew that high speed moulders ran fast, but I never would have guessed 1000s of feet per min!
Yea, I thought 200FPM was about max, til I looked at the Weinig site. It would really be interesting to see one run at 3000FPM!