Any tips for sanding to square blanks?

[ghansen4]

Any advice, tips, or tricks on using the offset sanding jig to square blanks? (Rather than a mill.)

• What grit sandpaper do you use for this?
• At what speed is the lathe?
• Do you do it before or after turning, sanding, and polishing the blank?

 

[JimB]

The grit you use will depend on how much material you need to remove. 150, 220, 320, 400 are all good. Go at a slow speed so you don't burn/heat the blank. Do it before turning. You are squaring the blank to prepare it for turning.

I also do a light touch after the finish is applied to clean up any finish that may be on the ends that will prevent good assembly of the pen.

 

[gtriever]

Greg, I use a HF 1X30 sander with a jig, but the principle is the same, so:

1) 150 - 180 grit
2) 3250 rpm, using a light touch
3) After gluing, and before it goes to the lathe

 

[mecompco]

80 or 120 grit, lathe running around 500 RPMs. Always square prior to turning. Rick's off-set jig is great and really speeds up the process. I ditched the wretched pen mill early on and have never looked back.

 

[Woodchipper]

Drill press with a machinist's vise and the pen mill from Woodcraft. I built a sanding disk and platform for the lathe but it takes too long to set up plus it wasn't accurate. JMHO.

 

[JimB]

Drill press with a machinist's vise and the pen mill from Woodcraft. I built a sanding disk and platform for the lathe but it takes too long to set up plus it wasn't accurate. JMHO.

Using a platform will not be accurate because you need the long sides that sit on the platform to be exactly square to the tube. That's not going to happen. Ricks jig uses the tube to square the blank.

I have a home made system I made before Rick starting making his. Mine works on the same principle as Rick's.
View in Gallery

 

[Silverado]

The tool that I added to my shop for this purpose is a Brynes Disc Sander. This machine I would never do without.(Priceless)lol

 

[Woodchipper]

the long sides that sit on the platform to be exactly square to the tube

I used a Groz precision square to align the disk and the side. Found the DP to be better; plus, it is set up. All I need to do is change the drill bit or the pen mill.

 

[Talltim]

To answer the original question, we do similar to mecompco.

80 grit. 400 to 500 rpm. Light touch.

Always square before turning or you will turn it out of square.

Rick's jig is great. Any solution that does not square to the tube will not give you a good fit in the end.

 

[TattooedTurner]

80 or 120 grit, lathe running around 500 RPMs. Always square prior to turning. Rick's off-set jig is great and really speeds up the process. I ditched the wretched pen mill early on and have never looked back.

Same here, 120 grit around 500 RPM. And yes, Rick's sanding jig is great. It's extremely precise and makes a quick job of squaring the blanks. As JimB mentioned, a light tough after finish will ensure the blanks don't have any CA or other finish on the ends.

 

[duncsuss]

the long sides that sit on the platform to be exactly square to the tube

I used a Groz precision square to align the disk and the side.

That's fine if -- and only if -- the outside of the blank is perfectly parallel to the tube.

It never is, that's why the platform did not work.

(Which is what JimB was saying.)

 

[edman2]

I also use Rick's sanding jig but I do something a bit different. I usually turn the blank down about 70% then I set up the sanding jig. It takes a great deal less time to sand it when most of the material is gone. After squaring the blank to the tube then I finish turning. Works for me.

 

[More4dan]

I turn my blank round between centers then drill on the lathe using a chuck. The inside hole is parallel to the outside diameter. I sand the ends square using a fence set 90 degrees to the sanding belt/disc.


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[Rifleman1776]

"Always square before turning or you will turn it out of square."

I'm missing something here. Turning make the object round. What point is there to sanding a square blank only to turn it round? Ends must be cut square but that is not what he asked.

 

[Talltim]

Perhaps the statement should have been expanded upon. But I do not believe anyone is talking about making the blank a square. The question is about squaring the ends and in that context this statement is correct in my opinion. If the blank is not squared to the tube it will not be square to the kit when assembled after turning the blank.

 

[ghansen4]

Thanks everyone, yes, my question was answered. However, as a follow-up: why does the blank need to be square before turning? I can understand why that is important for assembly but not sure why that would make much of a difference for turning...

 

[Jolly Red]

The ends need to be squared before turning to get them aligned with end bushings. Also, when using bushings, not being square would allow finish to get between the blank and the bushing, causing them to stick together. Squaring the ends after turning, especially if using a pen mill to do the squaring, could cause the finish to be chipped. If you are turning between centers using a dead center and calipers to get the size of the ends of the blanks, this would be a moot point. Also, it has been done for this way so long that it is "how it is done".

 

[Rifleman1776]

The ends need to be squared before turning to get them aligned with end bushings. Also, when using bushings, not being square would allow finish to get between the blank and the bushing, causing them to stick together. Squaring the ends after turning, especially if using a pen mill to do the squaring, could cause the finish to be chipped. If you are turning between centers using a dead center and calipers to get the size of the ends of the blanks, this would be a moot point. Also, it has been done for this way so long that it is "how it is done".

OK, I get it now. Using a guide in the track of a bandsaw or table saw is all I have ever done to square up the ends before turning. Never been a problem, I will square after turning, the tool usually only removes a tiny bit in the process. But, I agree, the ends should be square before turning, As an alternative, the blank can be removed before turning is complete and squared with a proper tool then put back on lathe for final turning.

 

[kentonjm]

I also use Rick's sanding jig but I do something a bit different. I usually turn the blank down about 70% then I set up the sanding jig. It takes a great deal less time to sand it when most of the material is gone. After squaring the blank to the tube then I finish turning. Works for me.

I like this approach. I also have Rick's jig but have always found it a pain when sanding the still square blanks. It takes long time and goes through sanding discs getting large parts of the end square that will shortly be turned away!!

I have a batch of blanks glued up ready for squaring so will give this a try.