Help....not getting perfect nib and band fits...

[PAbernathy]

Hey everyone...

I have noticed that I turn my blanks down perfect to the bushing, sand everything, Polish everything...assemble and the blank still sits a little proud of the nib or center band on some my kits....what am I doing wrong in order to get a perfect seemless fit...?

I use a mandrel saver.....could it still be a mandrel issue?... I know it could and more than likely a creator issue..lol....but my pens look perfect except for that...just feels perfect to the bushings right before assembly.

I have a caliper but obviously I stink at using it.....wish I could get a more seemless transition....any advice.

Here is the Pen...note it is a slimline so I kept it fat because I did not paint the tubes.

 

[1080Wayne]

The first thing to use the caliper for is to check that the bushings are the same diameter as the components they are supposed to match .
It is difficult to accurately use a caliper on a tapered piece such as you have on the pen shown .

 

[ed4copies]

There are MANY manufacturers of slimlines. Their nibs are NOT all exactly the same.

First order of business, measure your nib, make a bushing the same size. You can also do this by holding the bushing on the "press in end" of the nib and look at the bushing compared to the nib OD. They SHOULD be the same. If not, sand down the bushing (you have a lathe) to match the OD. That should make ONE bushing the right size for most of the pens made by that manufacturer.

Good luck!
Ed

 

[Woodkiller]

I use digital calipers to get the right fit. The bushings are only a guide to get me close, then I measure the kit part and match the finished blank to that.

 

[Quality Pen]

Even with a mandrel saver, the mandrel can be the issue.

My guess... for a new turner then that's probably the low hanging fruit.

Your mandrel can still be out of round as well with a mandrel saver. Definitely start using some calipers though. You can get a digital set from Harbor Freight for like 11 bucks.

 

[skiprat]

If you are sure you turned and finished to the bushing and you got the same bushings from the same vendor as your kits, then send the junk bushings back.
The quality of the bushings should be as good as the kits they are made for. They have been notoriously bad for years and they will never improve unless people stop accepting the bs.
Having to modify unfit and overpriced parts from a reseller is just dumb, imho:wink:

 

[PAbernathy]

I received the kit and bushings from PSI. The only kits I have purchased to date have been from PSI so not really a reseller..but I feel you and I agree.

It happens on the slimline whinch uses the stick 7mm bushings as well as the bushings for the tech bolt action kit and bushings. On the other kits so far it was fine.

Any tips to straightening a mandrel just in case that's a problem. Ironically I have used a mandrel saver from day one, I have never used the mandrel with the end nut...so not sure how I could have bent it, if that was the problem but I can try to fix it if that's a problem.

Thing is the "proud" ness of the blank is not uneven, it is uniformed so it appears to be turning right. I already have a Caliper so I just need to get used to working with it..again newbie here to woodworking or pen turning.

 

[PAbernathy]

Hey guys...I used my caliper on the nib of the 7mm slimline and it was .328 and the stock 7mm bushing is .332. So to get it perfect I would have to sand or turn below the bushing.

Am I being anal when striving for the perfect pen...new to the hobby so upfront coaching is appreciated. Once I push th pen together it's too late....also any tips on using the caliper on the blanks due to the angles.

 

[PAbernathy]

I was thinking of getting a ink stamp. I would push the end of the blank before I am finished sanding into the foam inker, then push it on a blank piece of paper so that I can then use the caliper to measure that circle that is left....all with light pressure.

What do you think....and of course confirm on the tube as well....just one more step to try and make it perfect.

 

[1080Wayne]

You are not being anal . Try the ink stamp and let us know how how it works . The greater the deviation from flat , the more difficult to get a good caliper measurement - one reason why I and others use a less pregnant profile . You can probably feel with your fingers as accurately as you can measure with a caliper on that kind of profile . I use the calipers on the blank off the lathe to get the best measurement , but as you can appreciate , holding the caliper squarely to the blank is critical .

 

[Mortalis]

Something I learned somewhere while watching some videos making pens was to radius the end of the blank after you get within .010" - .025" of the bushing. Radius the blank to the bushing. This fools the fingers into thinking the blank is transitioning into the nib instead trying to match the nib diameter. It may take you a few pens to get just the right amount of radius but it works for me almost all the time. I also use the calipers (I come from a machining background), measure the end of the nib and the bushing for variance and then turn one end down at a time watching the diameter. The calipers have very thin points for measuring the slightly tapered area. I use reading glasses to magnify my sight in close to see exactly how close I am to the end of the blank with the thin points of the caliper. Once I am .010" - .025" larger than the nib size I either use my 3/8" skew or sandpaper to round the corner of the blank to match the bushing.