# Custom Made Accessory - want to guess what it's for?



## ssnvet (Jan 10, 2012)

I've been trying to solve a nagging accuracy problem in our crating department. After looking into several options a customer of ours showed me their solution, and this is my modification of their design.










I'm ordering 1" bar stock and am going to make it on our tool room lathe and milling machine as soon as it arrives.

Want to guess what it's for?


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## ssnvet (Jan 10, 2012)

Hint #1

we're trying to solve this problem (economically)


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## shelly_b (Aug 8, 2012)

does it have something to do with drilling a centered hole?


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## 69BBNova (May 1, 2012)

I can't help but think it captures a nut to start and/or tighten it…

Or screw on a threaded rod/bolt to move a heavy load,


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## ssnvet (Jan 10, 2012)

Give that gal a gold star…

But the plot thickens…. why is this needed?

Normally you drill the counter bore first, and then use indent from the counter bore guide pin to center up the bit for the through hole….


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## ssnvet (Jan 10, 2012)

*I can't help but think it captures a nut to start and/or tighten it…
Or screw on a threaded rod/bolt to move a heavy load,*

your thinkin' but Shelly is closer to the mark…. it has to do with lining up the counter bore under "abnormal" circumstances.


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## ClayandNancy (Feb 22, 2010)

Drilling a thru hole from both sides so as to line up the bit


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## PurpLev (May 30, 2008)

redrilling on center for repurposing crates/pallets ?


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## bondogaposis (Dec 18, 2011)

Is it for making a counter bore around a hole that already exists.


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## ssnvet (Jan 10, 2012)

Bondo nailed it!

A little trick I learned is that if you forget to drill the counter bore first, you can take a scrap of plywood, and drill a through hole with the Forstner bit. Then center the plywood over the hole and tack it in place. Now when you drill the counter bore, the Forstner bit will be guided by the perimeter of the circle.

But there's still a twist, as in this case, the through hole is >8" deep and MUST be drilled from the top side with a template to ensure critical positioning. We used self feeding ship auger bits in a Super Hole Hawg, and no matter how hard you try, you can't drill the hole perfectly perpendicular. So when you do the plywood guide on the bottom, you start on center and at depth, you wind up off center, as there's no way to follow the axis of the through hole.


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## ssnvet (Jan 10, 2012)

Here's a diagram that illustrates the problem…


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## ssnvet (Jan 10, 2012)

Here's how a machinist would solve the problem… but these are not made in large sizes (at least not that I could find)


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## ssnvet (Jan 10, 2012)

Here's an expensive German woodworking solution. But again, not made in large sizes…


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## ssnvet (Jan 10, 2012)

This is what our customer came up with…










I noticed that the mounting shank on both pilots are slightly bent…. so I'm hoping that I have improved on their design…. but only time will tell.


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## ssnvet (Jan 10, 2012)

Here's a slick drill guide by Pro-Tool that Timber Framers use to ensure their peg holes are bored plumb…. With the drill, it's about an $800 set up.



















My boss likes it, but we've met our customer needs eyeballing it with the Hole Hawg for years… and now this one customer is kicking our buts. The only problem is, they only order every 3 months or so…. and their in-house generated design is not at all common (nor iaw. any ASTM or Mil. Specs for crating)


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## ssnvet (Jan 10, 2012)

We picked up one of these beasts at an auction for our maintenance dept., so we tried it out with decent results. But the thing weighs a ton and has a electro magnet base (It's made for drilling into the bottom of an eye beam up in the ceiling with a 6" hole saw :^o )










We used it on the last order with good results. But the thing has to be screwed down to the timber and it took two mean an hour to drill and counter bore 4 holes….. not going to make any money that way.


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## ssnvet (Jan 10, 2012)

A while back, I designed a set of custom tool kits for a differnet customer, who sends out crews to install printing presses all across the world. They have an even larger Milwaukee portable DP, and had fabricated a custom base out of 3/4" Aluminum plate.  The mag base goes into the kit seperatley and the field service techs. can swap them out as needed.










So my next project may be to design a custom base, possibley with an adjustable fence for us to use on ours.


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## shipwright (Sep 27, 2010)

Here's a bigger version used for boring a prop shaft on line. Exactly the same principle.

Outside










Inside


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## ssnvet (Jan 10, 2012)

Whoa! That's a serious long drill guide!


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