Shaft cutting problems

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
I use a 3 flute slot cutter.
Last pass at. 005".
UGRA CNC spindle and vfd.
3 minute pass 6 would drive me nuts.
That's a lot of air massaging.

Those whiteside 6 flute. 250" kerf slotter have too much pushoff for my liking.
 

whammo57

Kim Walker
Silver Member
a few things I have found to smooth cutting shafts on a Hightower Deluxe.............. I add 3 rubber bands to help the spring keep the roller on the taper bar....... I believe it was bouncing and causing a barber pole cut.... I also use a big C clamp to clamp a big rubber block to the router mount........ the added weight and rubber dampen any harmonic oscillations it might have........... I now get a surface that hardly requires sanding

Kim
 

scdiveteam

Rick Geschrey
Silver Member
I use a 3 flute slot cutter.
Last pass at. 005".
UGRA CNC spindle and vfd.
3 minute pass 6 would drive me nuts.
That's a lot of air massaging.

Those whiteside 6 flute. 250" kerf slotter have too much pushoff for my liking.

Joe,

If you set up an auto stop switch you can turn the machine on and walk away. I did both my saw machines for about 50 dollars total.

The 6 min pass will surprise you concerning RMS finish compared to 3 min. If your lathe wont go that slow, modify it with a DC motor and controller. Slower the better, you will be amazed. 6 mins seems to be the speed. Any slower does not seem to produce a better result. Diminishing return.

I use 80 tooth carbide saw blades at 139 rpm and 6 min duration and the shafts have a shiny burnish like feel and appearance.

I seal them with water thin epoxy and sand for less than 1 minute a few days later. Water thin epoxy penetrates over .010. Seals and case hardens the shaft forever.

JMO,

Rick
 

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
No reason for 6 minute pass here.
My taperer is powered by an X-axis mill auto feed.
Auto stop at ends.
CNN spindle spins a lot faster than saws.
 

scdiveteam

Rick Geschrey
Silver Member
Quote:
Originally Posted by JoeyInCali View Post

I use a 3 flute slot cutter.
No reason for 6 minute pass here.
My taperer is powered by an X-axis mill auto feed.
Auto stop at ends.
CNN spindle spins a lot faster than sawsoe,

Joe,

IMO, the travel speed has much more effect on the RMS finish than just the RPM of the spindle or the saw blade rpm.

The balanced saw blade with vibration dampener and proper drive belt is also a big factor. The blade also has at least 50 x more mass and therefore more stability than my 6 wing cutter with a 1/4" shaft on my CNC spindle.

Saw blade RPM is 3450

3450 x 80 cutters = 276,000 cuts per minute or 5 inches travel

276,000 x 6 mins = 1,656,000 total cuts on 30 inch shaft

When I cut custom billiard tapers on my CNC using my NSK spindle with a 6 wing cutter:

25000 RPM x 6 = 150,000 cuts per minute

150,000 x 6 minute duration = 900,000 cuts with a 6 wing.

A 3 wing cutter would be 450,000 total cuts using a 6 minute travel duration.

Using a 50,000 RPM spindle would get you back to 450,000 cuts in a 3 minute total travel / duration.

Again the travel speed and total duration is the Key to the best RMS finish along with the properly tuned Lathe or rotation RPM. IMO

To the OP, your question has many detailed premutations to consider to dial in your end result when creating a shaft. Every detail requires the utmost attention when dialing in your rig's set up or tuning.
[
I have noticed there is a huge difference in the RMS finish and more sanding required using my CNC compared to my shaft saw machine at the numbers shown above. Again, any longer than a 6 minute duration does not seem to yield a better result. On my equipment 6 minutes seems to be the Goldielocks situation. "Just Right "

JMO,

Rick
 
Last edited:

GBCues

Damn, still .002 TIR!
Gold Member
Silver Member
IMHO every machine is different and every machine has a different sweet spot - or set of them - which must be explored by the operator.
I used to use 6-wing cutters, but felt like they hammered the shaft and induced oscillations/barber-poling too easily. I believe Joey has found a place to send his out to get sharpened and trued, which I was never able to find locally.
I've tried 3-wing and 2-wing cutters, upcut and downcut endmills, etc.
But as stated above, you have to vary the spindle speed, shaft rpm's, and feed rate for each machine - and each cutter type for that matter - to find what works best for your setup.
My 2 cents,
Gary
 

JoeyInCali

Maker of Joey Bautista Cues
Silver Member
Joe,

IMO, the travel speed has much more effect on the RMS finish than just the RPM of the spindle or the saw blade rpm.

The balanced saw blade with vibration dampener and proper drive belt is also a big factor. The blade also has at least 50 x more mass and therefore more stability than my 6 wing cutter with a 1/4" shaft on my CNC spindle.

Saw blade RPM is 3450

3450 x 80 cutters = 276,000 cuts per minute or 5 inches travel

276,000 x 6 mins = 1,656,000 total cuts on 30 inch shaft

When I cut custom billiard tapers on my CNC using my NSK spindle with a 6 wing cutter:

25000 RPM x 6 = 150,000 cuts per minute

150,000 x 6 minute duration = 900,000 cuts with a 6 wing.

A 3 wing cutter would be 450,000 total cuts using a 6 minute travel duration.

Using a 50,000 RPM spindle would get you back to 450,000 cuts in a 3 minute total travel / duration.

Again the travel speed and total duration is the Key to the best RMS finish along with the properly tuned Lathe or rotation RPM. IMO

To the OP, your question has many detailed premutations to consider to dial in your end result when creating a shaft. Every detail requires the utmost attention when dialing in your rig's set up or tuning.
[
I have noticed there is a huge difference in the RMS finish and more sanding required using my CNC compared to my shaft saw machine at the numbers shown above. Again, any longer than a 6 minute duration does not seem to yield a better result. On my equipment 6 minutes seems to be the Goldielocks situation. "Just Right "

JMO,

Rick
You used to claim you took some 15 minutes or so on the final cut.
You and that best regards guy in Florida.

I really couldn't care less about cuts per minute .
If the cutter is no longer cutting wood, it needs to get out .

If your best cut is at 6 minutes, I think your spinner is spinning too slow.
Most like 200 RPM.

6 minutes would mean you take 2 minutes per 10 inches.
That would drive me nuts.
Total waste of electricity and more wear on the bearing and dust collector motor.
 

WilleeCue

The Barefoot Cuemaker
Silver Member
Vibration will make the shaft smaller ... the center is the most vibration prone area.
Shaft cutting requires a finely tuned machine and without being there and watching the thing run it would be hard to recommend a fix.
 

whammo57

Kim Walker
Silver Member
IMHO every machine is different and every machine has a different sweet spot - or set of them - which must be explored by the operator.
I used to use 6-wing cutters, but felt like they hammered the shaft and induced oscillations/barber-poling too easily. I believe Joey has found a place to send his out to get sharpened and trued, which I was never able to find locally.
I've tried 3-wing and 2-wing cutters, upcut and downcut endmills, etc.
But as stated above, you have to vary the spindle speed, shaft rpm's, and feed rate for each machine - and each cutter type for that matter - to find what works best for your setup.
My 2 cents,
Gary

I agree.....Every machine is different and you must see what works for you............. and for some reason sometimes you must adjust for the day............

Kim
 

Kim Bye

AzB Silver Member
Silver Member
Reducing vibration and harmonic distortion is key, but that needs to be done on a machine to machine basis.
A bit of wax in the center holes reduces friction. No matter if you ise a double sided, 3 wing or 6 wing cutter, it's a good idea to check how true those things are before you use them. On the 6 wing cutters I use, there has usually been one or two cutters that have been slightly bigger than the others, meaning that not all 6 heads actually are cutting.
 

GBCues

Damn, still .002 TIR!
Gold Member
Silver Member
Reducing vibration and harmonic distortion is key, but that needs to be done on a machine to machine basis.
A bit of wax in the center holes reduces friction. No matter if you ise a double sided, 3 wing or 6 wing cutter, it's a good idea to check how true those things are before you use them. On the 6 wing cutters I use, there has usually been one or two cutters that have been slightly bigger than the others, meaning that not all 6 heads actually are cutting.

Kim,
That was exactly the problem I had with mine. So, instead of a little slice of wood being taken out with every passing of a cutter, you only get one or two cuts - well, one cut from the longest cutter - and hence the hammering that I experienced. I WAS able to find a happy, harmonic, balance and was able to get smooth cuts, much like a sanded 220 finish.
YMMV
Gary
 

GBCues

Damn, still .002 TIR!
Gold Member
Silver Member
Since this is a topic that interests me, here's another question:
Has anyone tried setting up Constant Surface Speed Control (G96) on their CNC lathe?
I don't have CNC control of my RPM's to try it myself, but I'm soon moving to that capability.
Just wondering
Gary
 
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