# N-Filter help? PPD alignment? **URL:** \ **Category:** Proton Packs\ **Created:** [October 6, 2016, 10:31pm UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927 "2016-10-06T22:31:17Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![christof](https://forum.gbfans.com/user_avatar/forum.gbfans.com/christof/32/187349_2.png) [@christof](https://forum.gbfans.com/u/christof)\ **Post date:** [October 6, 2016, 10:31pm UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/1 "2016-10-06T22:31:17Z")
So as some may be aware I am in the process of my first pack build. I’m using a GBFans shell, and for the most part have been able to find all the fine details I have needed, however I just cannot find a reference to the diameter of the holes drilled around it. Additionally I have been wracking my brain for a better method of lining up the PPD cylinder, and was wondering if any of the much more experienced builders here might have some insights. Thanks! ---
**Author:** ![likesjellydonuts](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/l/65b543/32.png) [@likesjellydonuts](https://forum.gbfans.com/u/likesjellydonuts)\ **Post date:** [October 6, 2016, 10:42pm UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/2 "2016-10-06T22:42:58Z")
As far as I know, the holes in the n filter a half inch. I can measure when I get home in about an hour, but I’m sure someone else will chime in before then. I’m not sure I understand what issue you’re having with aligning the ppd though. ---
**Author:** ![demon-vice-commander](https://forum.gbfans.com/user_avatar/forum.gbfans.com/demon-vice-commander/32/186000_2.png) [@demon-vice-commander](https://forum.gbfans.com/u/demon-vice-commander)\ **Post date:** [October 6, 2016, 10:56pm UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/3 "2016-10-06T22:56:57Z")
> [@likesjellydonuts](#): > > As far as I know, the holes in the n filter a half inch. 0.5" diameter is correct. ---
**Author:** ![christof](https://forum.gbfans.com/user_avatar/forum.gbfans.com/christof/32/187349_2.png) [@christof](https://forum.gbfans.com/u/christof)\ **Post date:** [October 6, 2016, 11:40pm UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/4 "2016-10-06T23:40:25Z")
Thanks guys, I knew I had seen at least one mention that it was .50", and in reference photos that sounds correct just eyeballing it, but couldn’t for the life of me find it again. Re: PPD. It seems to sit with the tallest point angled towards the [booster tube](https://www.gbfans.com/wiki/equipment/proton-pack/booster-tube) and frame in every reference I have seen, but in others it appears to sit flat with the tallest point square with the base of the shell. I am certain the latter is just the angle of reference pictures, but I just can’t think of a solid way to replicate screen used placement without just eyeballing it. ---
**Author:** ![likesjellydonuts](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/l/65b543/32.png) [@likesjellydonuts](https://forum.gbfans.com/u/likesjellydonuts)\ **Post date:** [October 7, 2016, 1:00am UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/5 "2016-10-07T01:00:06Z")
It’s one of those parts, where you pick a pack you like and copy that. Really, whichever you prefer, is accurate. ---
**Author:** ![xyster101](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/x/e79b87/32.png) [@xyster101](https://forum.gbfans.com/u/xyster101)\ **Post date:** [October 7, 2016, 2:49am UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/6 "2016-10-07T02:49:25Z")
Check the tutorial section. There is a thread with a template. Just tape it on. [N-Filter](https://www.gbfans.com/wiki/equipment/proton-pack/n-filter) Hole Drilling Template (updated!) > **[N-Filter Hole Drilling Template (Fixed Broken Links)](https://forum.gbfans.com/viewtopic.php?t=30429)** > > Here is a template for drilling evenly spaced holes for your N-Filter. I posted this in my pack build awhile ago and it seemed to be popular, so I wanted to make it easier to find. If you’re building a plastic N-filter, I link to the tubing I used... ---
**Author:** ![christof](https://forum.gbfans.com/user_avatar/forum.gbfans.com/christof/32/187349_2.png) [@christof](https://forum.gbfans.com/u/christof)\ **Post date:** [October 7, 2016, 2:51am UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/7 "2016-10-07T02:51:30Z")
D’oh! I spent like two days SCOURING the [Proton Pack](https://www.gbfans.com/wiki/equipment/proton-pack) subsection, and I should’ve been looking in Tutorials! Thanks, Xyster! ---
**Author:** ![likesjellydonuts](https://forum.gbfans.com/letter_avatar_proxy/v4/letter/l/65b543/32.png) [@likesjellydonuts](https://forum.gbfans.com/u/likesjellydonuts)\ **Post date:** [October 7, 2016, 3:52am UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/8 "2016-10-07T03:52:27Z")
If you’re using acrylic tube like in that thread, be warned that it likes to grab onto drill bits and shatter. They make special bits specifically for the stuff, but I’ve had good luck with a step drill bit. ---
**Author:** ![demon-vice-commander](https://forum.gbfans.com/user_avatar/forum.gbfans.com/demon-vice-commander/32/186000_2.png) [@demon-vice-commander](https://forum.gbfans.com/u/demon-vice-commander)\ **Post date:** [October 7, 2016, 4:28am UTC](https://forum.gbfans.com/t/n-filter-help-ppd-alignment/15927/9 "2016-10-07T04:28:16Z")
> [@likesjellydonuts](#): > > If you’re using acrylic tube like in that thread, be warned that it likes to grab onto drill bits and shatter. They make special bits specifically for the stuff, but I’ve had good luck with a step drill bit. I also had excellent results using a step bit on the acrylic tube; the step bit is also an incredibly useful tool that can save you a lot of labor in drilling.