Shaper rotational speed and feed rates

[mark mcfarlane]

I'm setting up my shaper for some T&G doors and would appreciate a sanity check on my calculations.

Using the charts on page 22 of Eric Stephensen's book "Spindle Molder Handbook", ...

I'm using a steel Whitehill 120mm HSS insert head.

Looking up a 120mm steel insert head (PH) with high speed steel cutters (H), the blue line for the insert head (PH) hits the top axis for a 120mm head, which indicates a maximum speed of 10,000 RPM.

My choices are 4200, 8400, and 12,000, so I picked 8400 RPM.

For the feed rate, the chart on the next page says: for 8400 RPM and a PH (insert) head, my feed rate should be 10 metres/minute, or roughly 33 feet/ minute for the best finish, so I picked 33 fpm.

Performing a test 7mm*6mm long grain rebate cut on poplar, the finish was crisp, as if sanded...

1. So do these number seem reasonable?

According to how I understood the book, the species being cut only affects the type of cutter one would use, and has no direct impact on RPM or feed rate for a given head size/type.

2. So would I use the same RPM and feed rate for the MDF door panels ?

The book also describes 2 types of cutters: HSS and tct.

3. Is tct the same as carbide? Any one know what tct stands for?

[Wayne Lomman]

TCT stands for tungsten carbide tipped. With regard to your other questions, check that the machine manufacturer's recommendations are not being exceeded for the tooling you are using. Similar charts should be in your machine operation manual. Your set up is working for the rebate you have done. This is a low risk, straight forward shape to cut. Other more complex tool profiles will behave differently due to different loads so be prepared for the need to adjust settings. Timber species does make a difference. Its good practice to have a test piece available whenever a new profile/species combination is called for. Keep notes on your settings so that you don't have to work it out every time. Cheers

[Larry Edgerton]

That is the speed I would have used. Feed rate has to be slow enough for a good cut and fast enough to not burn. Sometimes you have to adjust, but if your results are good, you nailed it.

[Rod Sheridan]

Hammer Spindle.pdfCutter Speeds.xls

Hi Mark, your selection looks fine.

When I host a shaper seminar I tell participants to run cutter speeds of between 40 and 75 metres/second subject to tool manufacturers recommendations.

I've included a cutter speed chart I hand out, it's in Imperial units, I also have a metric one. If you change the RPM and the feed/drive speed in the Ft/min column, it will change the values for your machine.

I've also included a spindle chart from my machine showing spindle size, cutter size and height restrictions for my machine only. Your shaper will come with similar information which you must not exceed.

Welcome to shapers, one of the most versatile shop machines............Rod.

[Mike King]

Hammer Spindle.pdfCutter Speeds.xls

Hi Mark, your selection looks fine.

When I host a shaper seminar I tell participants to run cutter speeds of between 40 and 75 metres/second subject to tool manufacturers recommendations.

I've included a cutter speed chart I hand out, it's in Imperial units, I also have a metric one. If you change the RPM and the feed/drive speed in the Ft/min column, it will change the values for your machine.

I've also included a spindle chart from my machine showing spindle size, cutter size and height restrictions for my machine only. Your shaper will come with similar information which you must not exceed.

Welcome to shapers, one of the most versatile shop machines............Rod.

Rod, I presume that is meters per minute, not second?

[brent stanley]

Rod, I presume that is meters per minute, not second?

I haven't looked at the chart but it may well be rim speed of the head itself.

[Rod Sheridan]

Rod, I presume that is meters per minute, not second?

No Mike, it's metres per second.

40 m/s = 7,900 ft/min 75 m/s = 14,760 ft/min

Regards, Rod.

[Joe Calhoon]

That is the speed I would have used. Feed rate has to be slow enough for a good cut and fast enough to not burn. Sometimes you have to adjust, but if your results are good, you nailed it.

Same here Larry. Its more of a feel and sound thing. Its good to know the charts and to respect the min and max RPM marked on the cutters but in the end different materials and machines will behave differently and after some experience you develop a feel for it.

[Rod Sheridan]

Same here Larry. Its more of a feel and sound thing. Its good to know the charts and to respect the min and max RPM marked on the cutters but in the end different materials and machines will behave differently and after some experience you develop a feel for it.

Yes, calculations get you started then you optimize...........Rod.

[mark mcfarlane]

Hammer Spindle.pdfCutter Speeds.xls

Hi Mark, your selection looks fine.

When I host a shaper seminar I tell participants to run cutter speeds of between 40 and 75 metres/second subject to tool manufacturers recommendations.

I've included a cutter speed chart I hand out, it's in Imperial units, I also have a metric one. If you change the RPM and the feed/drive speed in the Ft/min column, it will change the values for your machine.

I've also included a spindle chart from my machine showing spindle size, cutter size and height restrictions for my machine only. Your shaper will come with similar information which you must not exceed.

Welcome to shapers, one of the most versatile shop machines............Rod.

Rod, in the pdf file, are the b=xxx curves the 'cutter length', and for an insert head, is the cutter length the height of an insert blade, or is it the total path length measured along the cut profile?

[mark mcfarlane]

It appears that the Whitehill shaper head I purchased can't be run at 8400 RPM. Bummer.

I assume the n rating in the picture below indicates the acceptable RPM range, so given my CU300 speed options of 4200, 8400 and 12000 @ 60Hz, I should always run this head at 4200 RPM, correct?

IMG_3626.jpg



...and I should also cut my feed rate in half from 33 to 17 fpm to preserve the cuts per inch...

The CU300 docs don't seem to show a max RPM based on tool diameter, it just says I can spin a 275mm head weighing up to 4Kg @4200 RPM with the tenoning hood installed (which doesn't come with the machine).

I have a 1.25" spindle (31.75mm), which of course isn't listed.

IMG_3631.jpgIMG_3630.jpg


And there is this somewhat confusing chart inside the spindle moulder door. I can't figure out what the distances are in the grid. It seems like they could be feed speeds, but I think the max feed speed should be faster for higher RPM's to keep the cuts per inch constant.

I am running HSS (B) at 4200 RPM, so something should be 10' 2/64"

IMG_3633.jpg

Lost somewhere in Italy,

[mark mcfarlane]

... and the charts from Eric Stephensn's Spindle Moulder Handbook indicate that running a 120mm diameter head at 4200 RPM is suitable for cutting: nothing.

IMG_3636.jpgIMG_3635.jpg

[brent stanley]

Hi Mark, a couple of things. The head is actually 125 mm in diameter, which might change the math a little bit if you use the spreadsheet (not much) , but what's important is that the critical diameter is the cutting circle diameter with the knives installed. So that's 125mm with just the little carbide rebate knives, but a lot more with HSS knives installed. You'd have to measure, but you're probably in the 165mm to 175mm range.

The RPM ranges for your machine are very strange. I think what MiniMax did was make it work well for European 50hz power (those RPMS are more typical) but instead of making new pulleys/motors for North American markets, they just used the same motor/pulley arrangement and allowed the RPMs to crank up and be kinda useless. The RPM range for that head are very typical of what you see, and if your machine had the 7000 RPM option, it would be right smack in the middle of the chart.

B

[Warren Lake]

Mark what are you doing. How many linear feet are you running.?

Im not the guy to tell you feed rate calculation because my focus is cut quality.

I decide my RPM head speed by safety first. I use older cutters than you I dont exceed the maximum speeds. I have but generally dont I decide by knife projection. If i have big cutters im under speed. I dont have 3,500 on all the shapers and 2,900 is my next choice.

Once ive determined my head speed I hand run and hear and feel my cutter. I then hand run it by hand or swing the feeder around. Industry will tell you about getting stuff done fast, about longer tool life and about kick back.

Are you industry or are you a guy making a custom piece?

Are you going to set up properly then you wont have kick back even with old cutters. The irony of this to me is even more so you have the latest fancy dancy anti kick back stuff, im using the Kamakazi older several generations back version and wont have kick back hand or feeder.

Are you in so much of a hurry that if it takes two minutes longer to run it through the feeder its going to change your life.

Last time I ran tongue and groove it was corrugated. I cant tell you what speed I ran but it was likely one of the lowest two speeds if not the lowest, because I want the best cut quality.



I also remembered that running this material my SCM combo feed rate is too high, I dont know what the rate is its too fast for this material, too fast on birdseye equals blow out, so I disengage and engage the feed and never let it come up to its full feed rate. Ill even hold it back as it accelerates again. In this case a more temperamental material, I get a clean cut because ive made my feed rate slower albeit an unconventional way. i have a molder and could have put straight knives in it and it has a gear motor so I can dial in what ever feed rate I want, just didnt feel like taking the time in this case.



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[mark mcfarlane]

Mark what are you doing. How many linear feet are you running.?

...Are you industry or are you a guy making a custom piece?

...Are you in so much of a hurry that if it takes two minutes longer to run it through the feeder its going to change your life.

Thanks Warren.

This particular run is 100 feet, in a home shop. The feed rate is inconsequential to anything I'll ever be building, other than trying to optimize cut quality and avoid burning.

It's my first time to ever run a shaper, so I'm just trying to get a starting point.

I'm prototyping with pine but the final door frames will be in soft maple with a 1/2" rebated MDF insert panel, then painted. Simple Shaker/Mission style.