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Hi all,
It's been a long time since I posted anything at SMC. Here's my question...
I'm looking to add a live tool (router) to my bench top lathe so I can machine some pool cues. The wood will likely be old warped house cues. So, I will need to machine out the warp from a spindly work piece. I've learned that a live tool is best.
What is the best orientation for the bit? ...an axial cut or a side cut? See pic.
thanks, Jeff
You will definitely need/want some sort of steady rest to keep the cue from whipping around. If you were using a steady with only two wheels (towards the back of the lathe), then positioning the router from the side would make more sense.
I made an adapter for a router and in retrospect I find it almost worthless - - bad design on my part. I welded a 1" dia steel post to a metal plate to which the router attaches. The post fits into a spare banjo. What I need to add is a "stage" with a leadscrew so that I can adjust the depth of cut. Right now the only way to adjust the depth of cut is to loosen the banjo and slide it in and out.
For your application you'll want a stage that can controlled in both dimensions. Take a look at a metal lathe taper attachment as it may have some value in terms of design.
BTW, some pool cues I've seen have a LOT of warp. You'd have to remove so much wood that the resulting diameter would be less that a pencil.
The attachment will use an x-y linear CNC bearings that are cheaply available on eBay. Attached is a pic of the conceptual design.
It is essentially a duplicator attachment that will follow a pattern of a cue's 'pro taper'. The attachment will also feature stepped cutting depths to enable light cuts to remove warp betterAttachment 378653.
I plan to only make shafts from the house cues. So there is plenty of meat. The butts will be made from virgin stock.
Here's a little better view of the "Y" carriage.
Attachment 378654
Too much stuff going on in that design. Just set the cutter head on an angled track to match start to finish, and run the cutter down the sides. Some sort of steady rest might be needed. I did 6 foot long bed posts on my lathe with skews and a long oak tool rest with 2 banjos.
Jeffrey, I'm sure a router would work fine. However, I turn long spindles like that with a skew chisel. I don't use a steady rest. One "trick" to make it easier is to hold one end firmly in a chuck instead of between centers. This makes one end a lot stiffer. Another thing is to hold the skew in one hand, using the other hand as a steady rest, the "left hand" steady rest. I haven't made a pool cue yet but I might.Quote:
Originally Posted by Jeffrey Makiel
With this method I've turned thin spindles like this, from 1/2" down to 1/16", I forget, maybe 26"-28" long:
Attachment 378663
One is walnut, the other pine shelving board from Home Depot.
This is a bigger diameter but longer shaft, hickory:
Attachment 378664
And 100s of these plus thin conductor's batons, etc:
Attachment 378665
I'm not saying this method would be easier or better for you but it sure is simple and needs no extra jigs, motors, guides. I have a PDF file that describes the method in more detail using a "magic" wand as the example. Send me an email address if you want the PDF.
JKJ
The best way is to hold the cue for turning is actually in tension with the 4 jaw chuck holding the headstock end and a live drill chuck holding the tailstock end if possible...
Best way to get a straight piece is to use a router in a jig that matches the shape you want, and slow turning speeds. Too much potential for whipping as you turn with hand tools, unless you are master class. Very difficult thing to do. I know there are videos up on You Tube about it because I looked into it once upon a time...
robo hippy
If you make a jig that will give you the taper with the router sliding alongside the jig, and you mount the router on a platform that slides along the jig, you can mount a 2 wheel steady behind the router on that platform.
That way the steady will follow the same taper the router does and keeps on steadying the workpiece, should work very good as you can have the steady rest close to the router.
I should have mentioned that pool cue shafts use a compound taper. That is, the taper is very gradual from the cue's tip to about 12" down the shaft. Then the taper increases for the remainder of the shaft. This compound taper is called a 'pro taper' and it is common in the US.
There are also conical tapers that sport the same taper along the entire shaft. This type of taper is common in Europe and often referred to as a 'European taper'.
Then there are varying tip diameters from 11.75mm to 13+mm. The diameter affects the taper because the other end of the shaft were it joins the butt is always the same diameter regardless of the tip diameter.
So, I was looking to make a few patterns as a low tech way to do this. That is why my design is really just a duplicator with a power attachment. CNC is the commercial answer, but that is not for me. I'm just not smart enough to deal with that nor do I want to invest in buying or building a CNC machine.
Based upon my limited turning experience, it is very difficult for me to remove warp from a narrow spindle like a pool cue even with a shearing cut. That is the biggest reason why I'm looking at a live tool.
One design detail is to keep the centerline of the router below or at an angle to the lathe axis. The dead center of a router bit does not cut, only the outer edges do. If the bit is so called center cutting, the finish will be poor at the center.
I think it would be easier to adapt an existing duplicator like this. You can replace the bars for longer if you need to or ask them to make longer ones when you buy. If you used the angle grinder with an Arbortech you would get a better finish than the pointed inserts in the Viel disc cutter. You could probably make an adaptor to mount a router. Those are the Canadian prices. US would be about 20% lower.
With your rig you could make both router positions and see which you like better. I think the largest diameter bit the router can use, mounted vertically, would give the best finish.