Making a spoilboard/T-nut workholding system

Discussion about Tooling and Fixtures. End Mills, Router Bits, Hold Downs, Fixtures, Etc.
WillAdams
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Making a spoilboard/T-nut workholding system

Post by WillAdams » Sun May 03, 2015 3:45 pm

Okay, going to work this out here as I work this up.

First, shopping (subject to updating), you'll need:

- SO3
- trim router
- 1/8" endmill
- 18"x24" half-inch cutting board (or similar) --- if the piece won’t fit between the lips of the end plates a suitable arrangement to lift it up so that it may be clamped in place levelly will be necessary
- ~88 T-nuts (#10-24 or similar)
- 3 clamps
- a 2x4 or similar guide less than 24" long
- suitable cauls to allow clamping the piece (need depends on clamps used)

Helpful when installing the T-nuts:

- one or more bolts as long as the the board is thick plus length of nuts and washers and matching nut
- the same number of largish washers
- a wrench or socket and ratchet

You’ll also need a suitable drill bit and drill to finish drilling through the Wasteboard to hold the board in place.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

WillAdams
Posts: 8489
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Making a spoilboard/T-nut workholding system

Post by WillAdams » Sun May 03, 2015 4:38 pm

Start by drawing a line.

We want to make it half the length, plus half the endmill diameter --- assuming an 18" wide stock, 9.0625" --- aligned along the X-axis at the origin.

import it into a CAM program, use a follow path operation to cut to a depth slightly greater than the stock thickness --- 13.5mm, used 14mm --- save the G-code
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

WillAdams
Posts: 8489
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Making a spoilboard/T-nut workholding system

Post by WillAdams » Sun May 03, 2015 6:06 pm

Use the board as a parallel guide, clamp the piece in place, orient the machine at the left edge, top surface of the piece so that the tip of the endmill is just barely away from the piece:

Image

Ensure that the endmill won't contact the front plate when cutting.

Run the file, (if desired, measure the slot width near the center to determine runout) return the machine to the origin, shut things down, slide the board over, re-clamp, position the machine so that the endmill tip is centered on the board (should be at the edge of the slot), re-run the file to finish the cut.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

WillAdams
Posts: 8489
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Making a spoilboard/T-nut workholding system

Post by WillAdams » Sun May 03, 2015 8:16 pm

Draw up a suitable pair of files, one should cut more than half of the recesses and holes for the T-nuts, the other the balance of them --- the centerline and rear fastening holes should be included in the first one cut. Origin should be machine front, center, top surface. After the first cut drill through the wasteboard at the mounting points, unclamp the board, fasten along the centerline, clamp along the front, drill through at the rear holes, fasten there, unclamp the front, drill / pocket the balance, unfasten the board, install T-nuts, reclamp the front ensuring the alignment and fasten the board in place.

Each T-nut should have a recess pocketed for its base (a little more than the thickest one) and a hole drilled (if your endmill diameter matches the outer diameter of the threaded portion of the T-nut) or pocketed to a little more than the thickness of the piece.

#10-24 T-nuts measure:

- threaded post - 6.3mm (~1/4" diam.)
- base: ~18mm diam. 1--1.25mm (rounded up to 1.5mm) thick

Make certain to check the file before cutting to ensure that all features will fit w/in the cutting area --- outside elements may need to be adjusted.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

WillAdams
Posts: 8489
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Making a spoilboard/T-nut workholding system

Post by WillAdams » Sun May 03, 2015 10:41 pm

Posted a .svg to the wiki --- due to the placement of the origin the preview only shows half --- open in MakerCAM to verify settings and export to G-code (for the first operation on the pockets).

Image

Link to the file on the wiki: http://www.shapeoko.com/wiki/index.php/ ... _first.svg

The complex pocket shapes aren't necessary --- one should differentiate the through holes for mounting by having them not have countersink areas. Also, the two mid-line holes need to be moved so as to not be in the way of the machine's frame.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

tekadept
Posts: 38
Joined: Sat Apr 12, 2014 7:48 am

Re: Making a spoilboard/T-nut workholding system

Post by tekadept » Mon May 04, 2015 1:55 am

WillAdams wrote:Okay, going to work this out here as I work this up.

First, shopping (subject to updating), you'll need:

- SO3
- trim router
- 1/8" endmill
- 18"x24" half-inch cutting board (or similar) --- if the piece won’t fit between the lips of the end plates a suitable arrangement to lift it up so that it may be clamped in place levelly will be necessary
- ~88 T-nuts (#10-24 or similar)
- 3 clamps
- a 2x4 or similar guide less than 24" long
- suitable cauls to allow clamping the piece (need depends on clamps used)
I'm Just wondering why you chose HDPE vs normal MDF? or would you still use sacrificial bit of MDF underneath workpieces to avoid marring the Holding Board unnecessarily

WillAdams
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Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Making a spoilboard/T-nut workholding system

Post by WillAdams » Mon May 04, 2015 2:11 am

I had a stack of HDPE cutting boards which I've picked up from a local restaurant supply store, and wasn't finding any pre-cut MDF, and got turned off on the idea of wood products for this after my initial pegboard idea didn't work out.

I've also got an idea for recycling a bit which I'm hoping will work out --- will hopefully be back to cutting tomorrow evening.
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

woodworkerbob
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Joined: Tue Apr 15, 2014 6:31 pm
Location: SVEMakerSpaces - Mesa, AZ

Re: Making a spoilboard/T-nut workholding system

Post by woodworkerbob » Tue May 05, 2015 2:43 am

Very interested in the spoil board T-nut location design. What are the planned hold down tools? Wouldn't the length of the tool help to define the spacing of the T-nuts?

Bob
Shapeoko 3 - #13, dust deputy, precision collets, limit switches.
SVEMakerSpaces

WillAdams
Posts: 8489
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: Making a spoilboard/T-nut workholding system

Post by WillAdams » Tue May 05, 2015 3:24 am

I've been using #10-24 T-nuts on my Shapeoko 1 in various configurations w/ various clamping systems --- I'll make up at least an initial clamping system out of the hardware as has been done by janapriya: http://www.shapeoko.com/forum/viewtopic ... 754#p42754
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

woodworkerbob
Posts: 243
Joined: Tue Apr 15, 2014 6:31 pm
Location: SVEMakerSpaces - Mesa, AZ

Re: Making a spoilboard/T-nut workholding system

Post by woodworkerbob » Tue May 05, 2015 3:37 pm

WillAdams wrote:I've been using #10-24 T-nuts on my Shapeoko 1 in various configurations w/ various clamping systems --- I'll make up at least an initial clamping system out of the hardware as has been done by janapriya: http://www.shapeoko.com/forum/viewtopic ... 754#p42754
Very nice. Any thought of making this system with 1/8" or 1/4" plywood? I know if I used the metal straps as shown I would drive an expensive (never the cheap one) end mill into it.

Bob
Shapeoko 3 - #13, dust deputy, precision collets, limit switches.
SVEMakerSpaces

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