Collet Chuck Question

[Rick Anderson]

I recently purchased the Penn State Collet Chuck set and am having difficulty using it with purchased dowels. I buy "furniture grade" hard maple dowels yet they still have some irregularities and are oversize by as much as 1/64" which makes the fit far tighter than "slide in". Have any of you been able to solve this problem by purchasing additional slightly oversize collets from Enco or similar sources?

I know that Beall sells more precise dowels, but at a premium price. With the amount of material I go through I hope to solve the problem more economically.

Any suggestions/solution would be appreciated.
Thanks!
Rick

 

[john lucas]

I'm definitely not an expert here. It appears to be an ER-16 collet. The have them listed in sizes in 1/32" sizes. I know my R-8 collets only have about +/- .010". I don't know the tolerance of the ER-16 collets. I found some in www.use-enco.com but you should be able to buy those from any machine supply house. I would try Grizzly as well.

 

[KurtB]

Rick,
You might be able to buy a dowel cutter, (hardened steel plate with holes sized to drive a dowel through), and true up the commercially available dowels with just a little work. Just an idea...

 

[GLENN ROBERTS]

Kurt, if your chuck uses ER collets, they have a 1mm tolerance ( internal closing capacity). They can be purchased individually or in sets (in 1mm increments). have a look on ebay for CTC tools (Hong Kong). Companies like them sell them for 'very' reasonable prices.
Collets are available in imperial sizes but given their large clamping tolerance, generally not an issue.

ER16 maximum collet size is 10mm, ER20 maximum collet size is 13mm, ER25 maximum collet size is 16mm

Hope this helps.

 

[Rick Anderson]

Thanks to all for your input. My project uses 5/8" dowels and usually requires making 150 parts each order, so getting this figured out will be worthwhile. Going to an oversize collet (they are ER-32 collets) will accomodate the dowel but I will still have to flip it around to true the first end in the collet. I would purchase a dowel plate if I could find one for 5/8" dowels because that would be the best solution. If anyone knows where to find a 5/8" dowel dowel plate without ridges to make grooves in the dowel I would welcome your input. Otherwise I will try making my own dowel plate.
Rick

 

[KurtB]

Collet

Rick, try here: http://www.woodcraft.com/Product/2005155/6577/Lie-Nielsen-Dowel-Plate.aspx.

 

[kenvalaska]

The Lie Nielson dowl plate is well built - you may also want to look at the Lee Valley opportunities. I have had better consistency with dowels from them than other sources I have tried for building things for my weaving wife.

For short pieces, I have used the dowel/plug cutters and they work well.

Bummer to have to add a production step, but I was able to make a good product with a router table and roundover bits for larger sizes and have used the router bit with a shop jig to cleanup some. Jig was like the beall threading jig except just cut rod to a consistent diameter using a small trim router and carbide endmills.

 

[jongibbs]

Lining Sleeve?

This might be a bit off-the-wall, so forgive me if it's no good.

...but have you thought about using an oversized collet and then turning a wooden reduction sleeve along these lines ? ...

I make wooden jaw linings for my conventional 4-jaw chuck for holding smaller and finished items after I saw John Berkeley use something similar in one of his demos.

Start by turning something akin to a top hat shape between centres to slip inside your chuck. Have the grain running lengthways and turn it so that the "brim" forms a reference when pushed up to the front face of the chuck - it doesn't need to be more than a small step. Then, with it held in the chuck, bore right through it with a drill equal to the largest diameter of your dowels. Then remove the sleeve from the chuck and create a slit lengthways with a saw into the hole. The slit may need to be broader than a single kerf to accomodate all of your dowels and still allow a tight grip. But bear in mind that the wider you make it, the less "true" will be the finished sleeve.

I hope this helps...

 

[jongibbs]

Missing Link.... DoH!

I had meant to link to this...http://www.axminster.co.uk/product.asp?pf_id=362891&name=collet+bush&user_search=1&sfile=1&jump=44

Sorry

 

[Joe Greiner]

If making your own dowels is not considered an additional production step, I might as well burn my engineering diplomas.

Your need for collets suggests some final turning on the dowels. If it's only for sanding, making your own dowels could make sense. But if you're adding features such as beads or end tenons, otherwise.

Consider a sanding jig (against a disk sander) to trim the dowel ends to fit the collet. If overdone, wrap with masking tape. That should be necessary on only the first few pieces while you develop your touch.

Or, consider the next size larger collet, with a thin sleeve of brass (or copper or plastic) tubing with a slit. The width of the slit can accommodate about 1/3 (but better assume 1/4) that much variation in dowel diameter.

More than one way to skin a cat; depending on what the cat looks like, before and after.

 

[john lucas]

Rick What I use to do what you are doing is the Vicmarc 100 chuck with the small extended jaws. They will adjust from 1"or more down to about 1/4". They are extremely rigid. I use them to turn Christmas ornament finials because they reduce the vibration so much. I also use them to hold the dowel for Wine stoppers and almost all other small projects. I have a set of R-8 collets and #2 morse taper collets but I find the chuck faster to use. The R-8 collets are only used in my tool handles, not my wood lathe just in case you were wondering how I used those.
If you are using 3/8" dowels, buy them from Nick Cook. His are very consistent in size.