Turning RPM and feed rate?
Flat ground blade?
Hi,
I have been building shafts for over 10 years and have used 5 different machines and for the last 7 years have used a saw machine. I use pivot taper bars and don't not wish to match someone else's shaft taper and don't take on that type of business. Persons should go to the original maker for that stuff IMO.
Joey's question concerning feeds and speeds are very relevant but once you find what works for you there are always way to tweak your end result for the better. Here is some stuff that I have recently done because of the need to do it.
I have found that 110 rpm at 6 minutes for. 30 " feed rate gives me a fantastic finish on my shafts without any lines whatsoever.
I use a 80 tooth triple chip flat grind carbide blade and the math works out to be over 3 million hits in 6 minutes on my machine.
No lines whatsoever to sand.
I recently modified my shaft machine tail stock to be adjustable and had more control over tail stock pressure. Relying on the length being the same on the shafts and spring pressure works but the are subtle differences in the ramp or embedment of the Sixty degree centers on each end that can be a tail stock variable. By leaving my spring loaded live center in place and adding a Vernier controlled adjuster to my tail stock I can get repeatable loading of the stock.
I recently added a new superpro taper giving me 3 shaft taper bars. Because the the contour was a 14" parabolic taper transitioning into a superpro taper (very thin with only a .0015 climb to the tip) I had a contour that wanted to bounce a hair in the center even with the lightest possible tail stock pressure. After making 10 shafts I found that I had 4 rejects because the diameter varied in the center and when rolled on the table you could see the variance under the shaft even though the shaft rolled good concerning the tip and ferrule staying and rolling good on the table.
The shaft taper plays very well for guys who want to have that big long stroke like Shane in a closed bridge. My other tapers have more spine and I never had this problem concerning frequence oscillation in the center with the other tapers.
So I recognized the root cause of the problem as being the transition point in the middle of the contour was a flex point. Since the shaft taper was playing so good to the big stroke guys I know who like the superpro deal I decided to keep the taper and address the problem by building a gantry over the centerline of my saw blade with a gravity feed Teflon round nosed cylinder as a follow rest.
It took me over a week to find the exact amount of weight in grams to find the goldilocks set point but I finally got it working perfect with about .001 run out on shafts that are lighter in weight. On the best shaft wood it is less than .001 and the RMS finish is so smooth that it is hard to believe. I thought I had the best finish to my shaft that was possible until I found the gravity rest made it even better.
I take all passes on all my shaft tapers now with this unit and it is absolutely wonderful concerning repeatable results. I am a happy camper since I have been loosing sleep over the recent rejected shafts.
So my corrective actions was to build the gravity feed rest and find the correct weight combo.
The lesson learned here for me was that the more I practice the art of cue making the more I find the devil is always in the smallest detail. Amen!
I hope my experience and details of my Shaft Program Procedure helps those who strive the raise the bar of expectation concerning shafts. Lets face it the shaft is the most important half of the cue concerning playability IMO.
Rick
Gravity feed Gantry follow rest featuring a Teflon bullet end for ring on the rotating shaft in the tapering process.
I recently modified my tailstock so that I could make oversize shafts for customers and found that having the spring loaded center and vernier control over the tail stock pressure was a very small adjustment the made a positive effect on repeatability due the the slight variation of the ramp of the 60 degree center on different shafts.
Added thrust bearing modification.
