turning dowel 1 mm smaller

[Gordon Stump]

Do you think turning a 19mm dowel down to 18 mm can be accurately done by sanding. Or should I turn it down to around 18.5 mm and sand down from there?

Thanks.

[roger wiegand]

I have more success getting a uniform cylinder with a skew, sandpaper tends to leave lumps and bumps. If you stick sandpaper to a board at least 6" long it helps. I use an open end wrench for sizing when I need reasonable precision, it is not prone to move. It is said (I haven't tried it) that you can sharpen the end of the wrench to turn to size.

The best and easiest way to re-size a short dowel accurately though is not on a lathe, but by using a dowel plate, a series of progressively smaller holes in a steel plate, you drive the dowel through, peeling off a bit at a time. They are available commercially or you can make one.

[John K Jordan]

Do you think turning a 19mm dowel down to 18 mm can be accurately done by sanding. Or should I turn it down to around 18.5 mm and sand down from there?

What wood? Some fine-grained diffuse porous hard woods may work better than something like pine with hard and soft rings.
"accurately"? What precision do you need? (curious about the application)

When I want the diameter of a cylinder to be close I turn with a skew after sizing a bit large every inch or so with calipers and parting tool (sorry, don't remember the amount) then use sanding sticks to take it down to the desired diameter. I make the sanding sticks by gluing (aerosol contact cement) sandpaper to 2"x8" plywood rectangles, either baltic birch or radiata pine which is pretty flat. I also make a set 1" wide.

(I've replaced these with new sticks recently.)
427197

So far this has gotten me to within a couple of thousandths of an inch over a 14" length in lignum vitae and olive without trying very hard, my two latest uses. After getting close I hold the stick sideways to even out the sanding.

I've also used flat cabinet scrapers held against the rotating wood. That takes a bit more practice. I round the corners to keep them from digging in.

You might also try a dowel plate or precision dowel cutter. Lie-Neilson has a metric plate but it only goes to 16mm. It shouldn't be hard to make one with a drill and slightly tapered reamer but I think it would need a good guide to keep the wood straight.

There is also this thing, which has inserts available for 19mm. Maybe depends on how many you need. It looks intriguing but I've never tried it.
https://www.fine-tools.com/G301830.html
https://www.fine-tools.com/duebelherstellung.html (not an inexpensive option)
(I want to make sometime similar to form short but precise #2 morse tapers on the ends of thin turning blanks.)

[Gordon Stump]

Thanks John & Roger. The wood is walnut. A customer who bought a flute stand on Amazon did not like the standard 5/8" peg for his C flutes. Rather than having him return the product I offered to make a "slightly" wider peg. He requested exactly 18mm. Woodworking is not the same as machine work! My commercially made dowels vary all over the place. I ended up taking a 3/4" walnut dowel down from 19+ mm to 18.5 mm and sanding starting with 120 - 320. I used my Vega duplicator.

Asking wood to remain a fine measurement gave me the willys. Thanks for the responses. BTW, Amazon keeps track of seller returns and kicks you to the curb if you get too many. I always work with the customer and in most cases mitigate a return.

[ChrisA Edwards]

BTW, Amazon keeps track of seller returns and kicks you to the curb if you get too many. I always work with the customer and in most cases mitigate a return.

I know this is off topic, but that perked my interest, I do a lot of returns of Amazon stuff and haven't seen any negatives other than occasionally having to pay return shipping, which is usually much cheaper than if I was shipping the same product myself. I searched Google, but could not find how Amazon ' kicks you to the curb' if you are a frequent returner. I usually price check the items, I'm buying, against other websites, and I don't see a price variance or premium charged by Amazon, so just curious for more information as I'm a frequent buyer from Amazon.

[Gordon Stump]

Hello Chris,

I knew I did not do a good job of explaining myself! I am also a frequent Amazon "buyer". They treat me like gold regarding returns. I am also an Amazon seller at Seller Central. They keep an eye on frequent returns, especial A-Z returns. They will cancel a seller account and basically put them out of business if there are too many issues. Recently the majority of my sales have been off my website. Normally most are from Amazon. My customers are terrific and the communication is more direct on my website. I am competing in a billion dollar business so I have no problem being a dutiful Amazon Seller.

Cheers,

Gordon

[ChrisA Edwards]

Hello Chris,

I knew I did not do a good job of explaining myself! I am also a frequent Amazon "buyer". They treat me like gold regarding returns. I am also an Amazon seller at Seller Central. They keep an eye on frequent returns, especial A-Z returns. They will cancel a seller account and basically put them out of business if there are too many issues. Recently the majority of my sales have been off my website. Normally most are from Amazon. My customers are terrific and the communication is more direct on my website. I am competing in a billion dollar business so I have no problem being a dutiful Amazon Seller.

Cheers,

Gordon

Thanks, much appreciated.

[Ken Fitzgerald]

I'm with John, I'd use a skew but I have had luck using a piece of sandpaper wrapped tightly around a small piece of flat wood too.