[gmercer_48083]

My Son made this assembly table (based loosely on the Ron Paulk design) with an add on swing up side to load large sheets of plywood. The upper section was made using 3/4" birch plywood. The basic bench size is 30"x 60" and has a swing up loading leaf that adds about 29".

He now wants to make dog holes into the top at 4" spacing in both directions using a 3/4" spiral router bit in a plunge router. The dog holes will perforate the complete top (similar to the Festool type top). I would like to know if any members here have made a jig to make repeatable holes to accomplish this, and how you did it. We don't have access to any machine shops to make any drilling jig and would like to make a jig from plywood to accomplish this. Any Ideas would be appreciated.

 

[JOAT]

He now wants to make dog holes into the top at 4" spacing in both directions using a 3/4" spiral router bit in a plunge router. The dog holes will perforate the complete top (similar to the Festool type top). I would like to know if any members here have made a jig to make repeatable holes to accomplish this, and how you did it. We don't have access to any machine shops to make any drilling jig and would like to make a jig from plywood to accomplish this. Any Ideas would be appreciated.

I'd just lay out lines at 4" intervals, going both ways, then drill the holes where the lines crossed.

 

[Herb Stoops]

I just laid mine out and drilled them.
Herb

 

[gmercer_48083]

Multiple cauls will be used to to support sheet plywood above the bench to cut them using a track saw. The cauls may be various lengths and will have pegs that locate them into the bench. For the pegs (in the cauls) to line up at different locations, the hole spacing must be as accurate as possible, and repeatable. The cauls will be removed when not using and stored so the bench can be used as a normal bench... or individual dogs or clamps can be added as necessary when needed. If the bench used just individual dogs the accuracy probably wouldn't matter, but since the cauls (long boards with pegs) are used... it would be nice to have the pegs align wherever needed on the bench and not only to the two holes that happen to line up.

 

[Nick2727]

https://www.leevalley.com/en-ca/sho.../benchtop-accessories/72602-dog-hole-bushings

theres a 45 second video on the page showing how they mounted the bushing to what looks to be plywood and hardwood scraps.

maybe something like this could help? have different sized plywood spacers for the different rows?

 

[MEBCWD]

You might check to see if there is anyone local that has a CNC that could cut you a template. You would need to make sure they know what you are doing and what size bushing you want to use.

It should be easy to layout in the design software and easy to cut on the CNC.

Where are you located?

 

[Biagio]

@gmercer_48083,
Gary, I was planning to use the LV bushings Nick2727 referenced, but with lockdown my Canadian friends who normally visit, were unable to do so and bring the goodies out for me.

My idea was to use a four-hole jig, at the standard Festool spacing, and make two of the holes large enough for the bushings. Then mount a fence underneath, to drill the first row of holes parallel to the front of the table/bench. Thereafter the fence can be removed, and two dogs (tight-fitting) can be used as positioners in the first row, to drill two holes at a time. That way, the spacing is constant in both directions, without the jig being able to rotate off square.
LV sells a drill bit matched to the OD of the bushings, and I think one for the ID as well. I planned to use a drill rather than a router - faster, possibly less messy.

Oh well, when lockdown ends.

 

[gmercer_48083]

You might check to see if there is anyone local that has a CNC that could cut you a template. You would need to make sure they know what you are doing and what size bushing you want to use.

It should be easy to layout in the design software and easy to cut on the CNC.

Where are you located?

I am in Troy Michigan

 

[gmercer_48083]

@gmercer_48083,
Gary, I was planning to use the LV bushings Nick2727 referenced, but with lockdown my Canadian friends who normally visit, were unable to do so and bring the goodies out for me.

My idea was to use a four-hole jig, at the standard Festool spacing, and make two of the holes large enough for the bushings. Then mount a fence underneath, to drill the first row of holes parallel to the front of the table/bench. Thereafter the fence can be removed, and two dogs (tight-fitting) can be used as positioners in the first row, to drill two holes at a time. That way, the spacing is constant in both directions, without the jig being able to rotate off square.
LV sells a drill bit matched to the OD of the bushings, and I think one for the ID as well. I planned to use a drill rather than a router - faster, possibly less messy.

Oh well, when lockdown ends.

I am considering a full length (60") 2 rows of 1" hole Jig to use with a 3/4" pc bushing and a 1/2" upcut spiral bit. This way to get 3/4" dog holes. Once the first row is routed into the bench, I can pin the jig to the first row of holes of the jig to the bench and do the second row... and progressively work across the bench.

Making the jig accurately is the most difficult part. To make the jig I would have to drill the holes with my drill press using another jig using pins and a guide fence to get the spacing right.

At least, this is my thought process for now.

 

[Biagio]

The difficulty you mention is the reason I thought of the 4-hole jig - much easier to get accuracy over 4 holes than over the 60" you envisage. Otherwise the idea is the same. With the first row laid out parallel to the front edge of the table (by the underslung fence), the next row will automatically be parallel to the first

 

[gmercer_48083]

Yea... a lot to think about

 

[MEBCWD]

I am in Troy Michigan

There are a few people in your area with CNC machines so maybe someone might contatct you if a CNC template would be something you would like to consider.

 

[bfblack]

Here is my shop built jig (1/4" Melamine) for drilling dog holes with a plunge router and guide bushings. Make sure you know the location of any metal on the underneath side of the table top; don't ask why I happen to know this bit of trivia.