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Posted: 11/11/2025 2:15:13 PM EDT
[Last Edit: SyberSniper][Edited]
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When using a jig and drill-press to dill out the main pocket holes, IMO one of the PITA time consuming tasks is to align the drill bit to each jig hole... Im thinking a center finder would be a big help in getting the drill properly aligned. I see Amazon has double ended ones for $10 and a Mitutoyo for $40 - both have reviews saying they don't hold up or that the ends fly off etc. I don't want to throw good money for a brand name if it isn't going to last. I know that the pointed center finder (for holes) are typically used stationary (power off) and the edge finder side is used with power on... but in this situation it would be to locate hole centers and so power would be off, so IMO either would work... but who knows what use will be required in the future... Any experience in this? Any recommendation of a good tool? Also they come in 3/8" and 1/2" - the jig drill holes are 3/8" so I'm wondering if the 1/2" would be a better choice - able to use for more things down the road. |
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A wiggler is a better tool Wiggler. Machinists tool  Using the Wiggler |
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My jig is similar - The #1 top-plate has a bunch of 3/8" holes for guides to drill thru (which is what I'm asking about) -my other top-plates are slots for using a router w/mill. I noticed he doesn't secure the work piece when drilling... I don't find that method agreeable... I have always clamped the jig securely before drilling a hole and I don't want it to get off... thus the PITA of aligning so many holes... I looked at the wiggler video and then others and even searched for how to use a wiggler to find the center of an existing hole - nothing really helpful presented itself... one page alluded to using the ball probe but no details. IMO the ball would have to be larger than the hole being probed... so more stuff to buy. The center finder looks to me to be a lot easier. |
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Loading and unloading a wiggler or center finder will take more time than using your eyeballs to align to the drill holes. Watch the drill closely, you can see it deflect if you are not properly centered. I would use a transfer punch in the drill hole jig plate to mark the forging, and then remove the jig plate and align the drill by eye. With practice you can repeatedly align to within a few thousands of an inch. |
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That sounds about how i would have done it a few years ago before my near vision got so blurry- these days I measure thrice,cut once...and hope it was right... I suppose I could bore shallow starter holes with the jig, say 1/8" deep, then remove the top and finish them as you indicate... as I recall from the last time, moving the jig around to align the holes and then clamping it in place was the PITA I am trying to avoid. I just don't want the bits to walk as they go deeper into the pocket, so the jig does act as a guide that would be absent if I tried to drill with just starter holes. OTOH I need a new tool to play with. |
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Yeah, I watched 19 min, just before he uses the clamps... imo freewheeling the small holes might be OK, except for the ones next to the outside walls - those I wouldn't want wandering or angled or the jig to get bumped, as the mill might not clean any oops. I was thinking of using angles for clamps too and it was good to go back and see how he did his. After watching it more, he does have some other good tips. I'm not sure if I can drill just the centerline of small holes and then jump to a larger drill to widen to almost full pocket width, leaving enough to mill clean sides... My jig plates don't accommodate stepping drill sizes and just go straight to milling... which can get dicey using a small hand router at 10,000+ rpm just below your face... His procedure looks a lot easier than what I was doing - I'll look into modifying that as well, maybe not use the router at all... Maybe I'm overthinking the drilling operation as more critical than it is... I don't really need a center finder if i make a better lever to lock my quill, I could just use the drill guide to position the bit like he does. IIRC last time it was such a pain because I couldn't keep the quill down while I did the clamping and something would always move a little. Still,I think I'll go with the Fowler centerfinder... Fowler being a good brand and this is an opportunity to learn to use it... if it doesn't work out, then not much $$ wasted. |
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I choose the jig I used because of no access to a milling machine. It had a learning curve and things to avoid just like doing a complete lower on a drill press does. Drill presses I have seen had depth stops that were inaccurate or moved during use and tables that were off some from 90 degrees with the bit or tool. Moving the table up and down for bits lengths always resulted in having to realign the work piece. The jig I used was made for their billet lowers they sold at the time and needed more adjustment in the top plates side to side for alignment on varying widths of forgings. Also, depth drift in the outside 1/8" holes sometimes left lines in the lower sides it you drilled them to depth. The jig needed drill bushing on both sides too to make it easier to get accurate trigger hammer holes. But I think the worst thing about drilling small holes is if you let a small bit pop into the hole drilled already for the pistol grip screw and break a piece of the bit off leaving it stuck down in the lower. |
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Yep, I ran into some of those same setup issues with my drill press. IIRC I used a level, laser pointer and drafting triangle to get the table squared up. The jig I ended up with wasn't my first choice but it was all I could find available at the time - the others were 'sold out'. Fortunately I already had a compatible router so just had to get the right mill. I guess I was lucky or extra anal, as I didn't ruin any work and have no issues with any of my lowers after 3 years use. This time around I'm trying to anticipate some of the operational issues I had last time. I might give the drill press another look as using the router makes me nervous - it only takes one oops... I didn't trust the quill stop either so I used drill stops. They can also slip if your not careful. The stop on the drill press is coarse and difficult to set accurately- it needs a better handle/finger screw or something... although once set, it does hold good-I have used it to trim 223 brass. I have done thousands and I do measure frequently-they are dead nuts 1.750" so its a matter of making the adjustment easier to use. |
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This is when you use a pin gauge that is .001/.002 undersize of the hole in the jig to find the center. Insert pin gauge into quill/chuck......then just move the quill/chuck using X and Y to the jig hole while the machine is turned off. Or if the quill/chuck has a non-rotation setting while it is powered up, do that. Move the Z down when the pin is just above the hole, and move X and Y until the pin gauge is over the hole and can slide up/down smoothly into the hole without binding or hitting the edge of the hole. Once you are happy with the location, lock down the table (manual mill), double check your center with the pin 1 more time, then switch the pin gauge for a drill bit and drill the hole. On a drill press, you just slide the jig into position, put the pin gauge in the drill chuck, drop the pin gauge into the hole, carefully clamp the jig down, verify the Z location is smooth going in and out of the hole, swap pin gauge for the drill bit. Just make sure the jig is clamped down really good, and also verify the drill press table is also locked down really good. This will also work with drilling the trigger/hammer/safety holes. . |
Occid Vel Occisus Est !!
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That's basically what I did last time, 'cept I just used the drill bit instead of a pin gage. That part wasn't too bad, it was moving the table and jig around then re-clamping for every hole that was a PITA. Its been too long for me to remember the details but I seem to recall there was something about the length of bit & quill travel vs the need to raise/lower/realign the jig after every hole. |
Use edge finder and center finder daily....and while I mill 80%'ers on the Haas, I have a 5D tactical jig and it works great for pocketing if you like deafening noise and chips in yer shorts..... It is effective. I don't trust them for FCG holes.....I put em on a manual mill locate datum and then XY to the points. Nothing but carbide tooling....spot holes with 1/8 carbide the finish a .152 (can't remember wire size number and plunge the selector hole with a 3/8 endmill....guess I need to make a jug with drill bushings that pins into the takedown holes. |
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