Hey Coldman! You've always had good advice and even if you didn't, input is always appreciated!
The reason there's a gash on the 1/8 is because it went off the track when I was cutting it off since I wasn't doing it right hence user error. You can't argue that either.
If you hold a rod there for a long time it will melt the plastic a bit but you should be cleaning your Tungsten after you grind regardless but yes one out of 3 Tungsten rods having a small amount of melted plastic isn't ideal. Using acetone will remove all ABS since it naturally dissolves ABS, and would clean all the dust you just put on there off as well. I have other plastics for my 3D printer that can handle actual fire, and Nylon is fairly resilient but ABS in itself does a great job. TIG'er's often forget that TIG Torch you hold is made out of the same ABS plastic I'm using although Delrin is sometimes used too.
The grind marks are relative to the spin you put on the electrode and you might have noticed I was not spinning the same direction each time because it's been awhile. Near the end I did and that's why the 1/16 go the good grind. If you spin the rod fast it gets a beautiful spiral and that's with this or any of the 3d printed grinders. It's not like something just magically changed. I'll also add to date I've never had arc wander from any electrode I've ground down with these attachments but had my fair share when doing the bench grind with the occasional oops.
The angles are not all over the place. They were specifically made to 10 degree, 20 degree, 30 degree, and 40 degree.
As for going out of round, that's again user error. The more stable you hold it, the more round it will be. If you spin fast and get it done fast, there is zero issue. The 3/32 gives the better example of this. The same would still hold true for a world class precision made grinder because if you don't give a good spin, you will have a flat spot i.e. out of round.
As for clamping the Dremel to a bench being better, that's still not true. Two different points in a plane will always a more solid path when forcing an object against them since you create friction which guides them vs. a single point of contact in a plane since a single point of pivot will always offer unlimited angles with zero friction vs. the latter.
So I will say your comments of fail are very over zealous, but likely about as much as the overall appreciation I have for the end results
![Smile :)](./images/smilies/icon_e_smile.gif)
Since I have over a year of using this type of grinder I can at least say it's not the Kruger effect either
![Wink ;)](./images/smilies/icon_e_wink.gif)