Coring dowel diameter not consistant after a pass

[blackhawk357m]

I am using a Cue Smith Deluxe lathe with a power feed, Ridgid router, Todd's router mount with a 6 wing carbide cutter. Using the ground pin in the headstock that came with the lathe to check runout (@ about .001) I loosened the tailstock drill chuck and tightened on the headstock pin, then tightened up the hold downs for the tailstock.

After taking a 0.025 pass on the dowel (not using any taper bars), the tailstock end of the wood is a larger diameter than the headstock end. Example: Tailstock end would mic out @ 0.750, Headstock end would end up @ 0.741

It's not always a 0.009 difference, it ranges from 0.004 to 0.012. Forgot to mention, that I've used both a large live center and the small spring loaded live center to not put the wood in any bind.

Any thoughts or ideas?

Thanks for any info and help,

Nathan Brugmann

 

[whammo57]

I am using a Cue Smith Deluxe lathe with a power feed, Ridgid router, Todd's router mount with a 6 wing carbide cutter. Using the ground pin in the headstock that came with the lathe to check runout (@ about .001) I loosened the tailstock drill chuck and tightened on the headstock pin, then tightened up the hold downs for the tailstock.

After taking a 0.025 pass on the dowel (not using any taper bars), the tailstock end of the wood is a larger diameter than the headstock end. Example: Tailstock end would mic out @ 0.750, Headstock end would end up @ 0.741

It's not always a 0.009 difference, it ranges from 0.004 to 0.012. Forgot to mention, that I've used both a large live center and the small spring loaded live center to not put the wood in any bind.

Any thoughts or ideas?

Thanks for any info and help,

Nathan Brugmann

If the tail stock end of the dowel is larger then it is not close enough to the cutter. Move the tail stock out half the difference of the error and it should be just fine.

Put a dial indicator on the tail stock .... loosen the set screw in the back and move it. Tighten it down when you are done.

If you want to see what you are cutting...... spin the dowel and hold a pencil on it and run it down the dowel to put a spiral line on it............... then take a cut............

I spin the dowel about 300 rpm and move the feed about 10 inches per minute.

Be sure the cutter is sharp and that the bed is lubed and that the top slide is locked down.

Kim

 

[blackhawk357m]

So then I would have to move the tailstock with every dowel then, right? Since each dowel has a different variance of diameter.

 

[Busbee Cue]

If I am going to run a bunch of pieces the same length here is what I do.

Run a straight pass on a dowel that is the length of all the dowels that you will be cutting. After running a pass measure each end and see what the difference is.

At the tailstock end assuming your cutter is on the left side of the lathe looking toward the headstock, if the dowel is bigger at the tailstock end measure the difference and divide that in half and move the tailstock closer to you by that amount, if the tailstock end is smaller you would move the tailstock away from you. Keep doing this and run a small pass until each end comes out to the same size.

Hope that this helps.

 

[Busbee Cue]

Kim and I must have been answering at the same time.

Kim added some good info on making sure your cutter is sharp and everything is lubed with your gibbs being set correctly.

Only time you would have to redo this is when your turning piece is either longer or shorter.

 

[whammo57]

One thing I didn't mention is removing the tail stock from the lathe and clean the chips out of the bottom........ sometimes they get under it and into the V grooves at the side.

Once you have it tuned in, it should be ok for that run of dowels. I usually get mine within 5 thou and call it ok............... works for me.


Kim

 

[blackhawk357m]

Thank you for the info and tips guys, I really do appreciate them. After doing some research & reading, I noticed that the carriage was kinda sloppy. Meaning I could rock it left and right on the bed. So I ended up adjusting the gib screws on the back. Got it to where it's got slight pressure turning the hand wheel, but no play in the carriage now. BUT, I do notice that it turns more freely the closer I get to the headstock...but no play now. The closer I get to the tailstock it gets a little harder to turn the hand wheel.

Maybe it's from doing more tips and ferrule work wearing more closer to the headstock?

Anyway, it's almost 2AM as I type this, and my family would kill me if I turned the router on now to check it out lmao....I'll find out tomorrow

Thanks again guys, you are all top notch!

Nathan

 

[JoeyInCali]

Remove the gib and check it's flatness and straightness.
You might have to lap it .

 

[Dave38]

Thank you for the info and tips guys, I really do appreciate them. After doing some research & reading, I noticed that the carriage was kinda sloppy. Meaning I could rock it left and right on the bed. So I ended up adjusting the gib screws on the back. Got it to where it's got slight pressure turning the hand wheel, but no play in the carriage now. BUT, I do notice that it turns more freely the closer I get to the headstock...but no play now. The closer I get to the tailstock it gets a little harder to turn the hand wheel.

Maybe it's from doing more tips and ferrule work wearing more closer to the headstock?

Anyway, it's almost 2AM as I type this, and my family would kill me if I turned the router on now to check it out lmao....I'll find out tomorrow

Thanks again guys, you are all top notch!

Nathan

Did you buy it used or new? If used, then the bed maybe worn at the headstock side of things and it will definitely need constant tweaking until you buy a new bed for it.
If you bought it new, and have used it for a few years....lube it at least once a month or sooner as you are wearing it out. If you need a new bed, Chris will take care of you....once the SBE is done...lol
Dave

 

[whammo57]

Remove the gib and check it's flatness and straightness.
You might have to lap it .

Hightower also sells a delrin gib that seems to move a little smoother,,,,,,, easy to change,.......... the original is brass.

Kim

 

[Kim Bye]

Thank you for the info and tips guys, I really do appreciate them. After doing some research & reading, I noticed that the carriage was kinda sloppy. Meaning I could rock it left and right on the bed. So I ended up adjusting the gib screws on the back. Got it to where it's got slight pressure turning the hand wheel, but no play in the carriage now. BUT, I do notice that it turns more freely the closer I get to the headstock...but no play now. The closer I get to the tailstock it gets a little harder to turn the hand wheel.

Maybe it's from doing more tips and ferrule work wearing more closer to the headstock?

Anyway, it's almost 2AM as I type this, and my family would kill me if I turned the router on now to check it out lmao....I'll find out tomorrow

Thanks again guys, you are all top notch!

Nathan

Have you checked for small bits of glue and such, on the backside of the ways?

 

[conetip]

I am not really sure about your machine, but it could be that there is a slight warp or twist in the lathe bed possibly. The fix is to get the lathe bed in alignment. On my setup, I can tighten down one side by putting some shims under one side and not the other. It does not take much to twist these taig type lathes. In my case I have a steel top and an Ali support underneath. It's a bad idea as when the temp changes it is like a bi metal spring and moves. For me it is best to keep it at as even a temp as I can. Setting up Lathes initially is a lot more time consuming that most allow to get it right, but is really worth while doing. The twist is the 1st thing to get figured out. lots of ideas and ways of doing this. 1 simple way is to get 2 straight bars, and a laser level. The bars want to be about 24 inches or so long. Sit one at one end of the bed and align the laser level to be just touching the top of the bar at the end. As you move the other one down, Ideally the light will just be shining on the top of the other bar. If the bed is twisted, the amount of twist will be magnified at the end of the bar by a factor of about 10 or so.So 1 thou across the bed will be 10 thou at the end of the rod. When you have the twist taken out of the bed, then you can go about setting it level. After that, then you can start setting up the headstock, and then the tail stock. If you have fixed bearing steadies, it may be possible to set the headstock to those and then finally adjust the tail stock to suite. The headstock can be influenced by the amount you tighten the front to the rear clamping screws as well. When you find the torque settings that make it straight, record them, so that when you move the headstock up and down the bed, torque to those settings and it will be very close to right each time.
If the bed of the lathe is not set true to begin with, you will always be adjusting the tail stock etc. You want the head stock, bearing steadies and tailstock all to correctly align, so that when you drill and tap holes, either directly to the headstock or being supported by the steady rest, it all aligns up. Nothing worse than having to reset every time a distance changes etc.
Neil

 

[john coloccia]

FWIW, if you want to go nuts,you can get steel rod that's good to .001" per foot, and it's not that expensive. It's Thomson 60 Case designed as a linear bearing rod. Chuck it up on both ends and indicate off the carriage. If you go too far you may need to support with the steady rest in the middle (indicate off the top to check for sag).

 

[JC]

So if you can't turn a dowel rod straight with your lathe then what implications does this have with a 30 inch butt or shaft and the taper bars? To me that is a larger concern. You can't be re adjusting the tail stock for every thing you want to do accurately and expect to enjoy the process.

BTW I found exactly the same problem with my Deluxe and have yet to resolve it. I use my saw machine to cut pretty much everything because of this.

JC

 

[63Kcode]

It's not a problem limited to Taig lathes. Even the best lathe beds require tweaking after moving the tailstock. Want to se Mr. Drexler freak out? Move the tailstock on his high end CNC tapering machine. Wish I had a camera with Me!

Larry

 

[Kim Bye]

So if you can't turn a dowel rod straight with your lathe then what implications does this have with a 30 inch butt or shaft and the taper bars? To me that is a larger concern. You can't be re adjusting the tail stock for every thing you want to do accurately and expect to enjoy the process.

BTW I found exactly the same problem with my Deluxe and have yet to resolve it. I use my saw machine to cut pretty much everything because of this.

JC

This is a very good point. I'm not having a go at Chris or speaking negative about his products (I own a deluxe cue lathe...) but there are limitations, sure, you can build a cue on a deluxe and many people do so. I didn't really understand the difference myself, before I worked on a real metal lathe and saw first hand how much more robust, sturdy and precise, even a Chinese made metal lathe is.
The big benifit with the Deluxe, Cuemonster, Porper and similar lathes is it's light weight.
But the light weight comes at a cost, just look at the difference between a live center for the Deluxe and a MT3 live center or the mini AXA toolholders next to a BXA toolholder.
And the chuck of course, even though a 6" chuck is considered small for a metal lathe it still weights more than the whole motor unit on a Deluxe lathe.
The issue with constantly having to readjust stuff is I think something you have to live with if your only setup is a Deluxe or similar dedicated cue lathe.

 

[Busbee Cue]

5C Spin Indexer

wrong thread................................

 

[blackhawk357m]

I bought the machine new. After adjusting the gib, and today readjusting the level of the bed...it's cutting a lot more accurately. I understand that this lathe is in no way up to the same specs as a good metal lathe, but as was stated, there is a trade off...and I agree with that.

Now about the taper, I think there is a huge difference between cutting straight on a dowel relying only on the bed and gib to keep the cutter straight as opposed to turning a 29" butt utilizing the taper bar that has constant pressure on it from the cross slide spring keeping it along the path of the taper.

Or am I wrong in thinking that?

 

[cueenvy]

The beds need to be dead level....often they are not. Either they aren't mounted to the board level, or the surface the lathe is on isn't level and the plywood flexes.

 

[whammo57]

So if you can't turn a dowel rod straight with your lathe then what implications does this have with a 30 inch butt or shaft and the taper bars? To me that is a larger concern. You can't be re adjusting the tail stock for every thing you want to do accurately and expect to enjoy the process.

BTW I found exactly the same problem with my Deluxe and have yet to resolve it. I use my saw machine to cut pretty much everything because of this.

JC

Once you set it up ............. it will repeat.............

you may need to reset it next time.............

so what????

Kim