I bored my first clone body today

The Malkoff MD3 body was too tight to fit the latest-greatest Panny 18500 cells, the protected 2000 mAh series. They were wrapped over the original wrapping and the PCB added and the sticker stating what they were.

By a tiny fraction of a mm, almost but no way, no how.

Amazingly they fit into other bodies I had, so it must have been this specific body that had issues. In the past I've dealt with that issue by removing the stickers, this time it hasn't helped.

I only had relatively fine sandpaper, I think it was 400 instead of 100 that you really need to make things go faster but didn't feel like making the trip to the local Home Depot. So 400 had to make do. I looked around what too to use and found out that I had a long ratchet extension, 3/8" that was ideal more or less. There must be better tools for the purpose but since I do this once per decade it seems, the 3/8" extension worked just fine.
I wrapped the sand paper around in several layers so the fit was perfect.

It took longer than I thought, about half an hour. I was sweating due to the effort. I kept checking every 40 seconds hoping the task would finally be over but they wouldn't fit and wouldn't fit - until they finally did. I like tight fit and battery rattle drives me nuts but not that tight where you have to punch out the cells with a pencil or something. That would really be bad in some situations. To begin with, the cells wouldn't go in even 1/4".

I also had some very fine sandpaper, I think it was at least 800, maybe even finer and I used that towards the end, that made it real smooth inside.

Turn on your fav Netflix show and it makes the time go faster. You don't have to look at it, just stop every few minutes to check out.

Anyway, now I am very pleased, I can run the Hound Dog in the MD3 configuration with latest-greatest 18500 cells.

Now I can definitely say that by hand it will take hours to bore a 16mm body to 18mm, although that can be cut down to probably 10 minutes with a dremmel tool and the right extension. Here essentially I enlarged an incorrectly shaped 18mm body, a bit on the tight side in conjuction with super thick cells.

I think that one of my MD4 bodies could use just a hair of work, most of the 18650 cells fit but not all.

Thanks for sharing your experience, etc. I have a U2 Gen1-2nd version battery tube that I was able to get the battery sleeve out of easily after letting it sit in the freezer for awhile, but there is some residual black adhesive stuff left that I want to get rid of, and I'm trying to think of a relatively gentle way to remove it. Neither acetone nor Goof-off had any affect, so some abrasive is in order. Maybe fine sandpaper, maybe moto-dremel. Your post has been a renewed call-to-arms.

I decided to resume the work on the MD4 body, some of the 18650 just don't fit.
Just got back from Home Depot. 100 is too coarse IMO if you want to take off a little bit, you need 100 grain if you want to go from 16mm to 18mm. I ended up getting 220 grain sandpaper seems like a happy medium to work with and you finish with very fine 800 grain.

MD4 took a long longer than MD3 for some reason, maybe the surface area was larger

Now both slide in and out smooth with all the cells I have.

Beautiful

Start with 150 grit to speed up the process and graduate to fine 220 grit and in the end, can apply some 400 grit.

Although what I had on hand was lots of 220 and some very fine 600 or 800 so that worked also. Just takes much longer. If you need to open up a 16mm body, def need 100 grit and some dremmel tool attachment as by hand it will probably take 8 hours.

It's nice if you can buy sandpaper with various permutations, like 150/220/400 all in one. I did see 80/150/220 in Home Depot but 80 seemed way too coarse. Although I am not 100% sure.