MFT-style vs. Trad-style workbench design (is there a middle ground??)

[thikone]

Yeah I’ve seen these, they look like they solve the dusty issue quite well! Benchdogs make the magnetic steel ones but are quite pricey and Axminster sell bright orange ones which seem more affordable.

Do you have your 3D printed ones in all your dog holes?

I want to print more, maybe two dozens. The ones I modelled are for 19 mm holes. They are 8 mm tall and take M5x8 bolt in the middle. It is indeed easier to take them out with a magnet. Have to chamfer some of the holes more so that they sit below the surface though.

I do also repairs on electronics and such on my bench and it is very hard to find a small screw if it falls through the holes... Scrap wood pieces and shavings that accumulate under workbench hide them pretty well, even without sound sometimes. Other things like dowels or dominos do that too. Workbench has middle part without holes and the ends but I do wish there were more holes sometimes. Falling through shavings and dust also annoys me but not as much.

So maybe I will cover all of them and remove only when needed. I also have apron with dog holes, perhaps I can store removed ones there. I also like VERITAS Prairie Dog in some of the holes, maybe I get more as they help with that too (requires thicker worktop than mft of course).

 

[paulrbarnard]

I want to print more, maybe two dozens. The ones I modelled are for 19 mm holes. They are 8 mm tall and take M5x8 bolt in the middle. It is indeed easier to take them out with a magnet. Have to chamfer some of the holes more so that they sit below the surface though.

I do also repairs on electronics and such on my bench and it is very hard to find a small screw if it falls through the holes... Scrap wood pieces and shavings that accumulate under workbench hide them pretty well, even without sound sometimes. Other things like dowels or dominos do that too. Workbench has middle part without holes and the ends but I do wish there were more holes sometimes. Falling through shavings and dust also annoys me but not as much.

So maybe I will cover all of them and remove only when needed. I also have apron with dog holes, perhaps I can store removed ones there. I also like VERITAS Prairie Dog in some of the holes, maybe I get more as they help with that too (requires thicker worktop than mft of course).

I have a tin of the bench dogs ones and they are invaluable when working on small parts. Expensive to purchase but they will last forever.

 

[curryjunkie]

Actually, I'm about to build something MFT like myself this year - for power tools and also as router table where I can finally make use of Incra LS Positioner. Router plate has a magnetic cover for the hole when not in use and holes grid can be used to place that Incra contraption in desired position and calibrated. Probably not so much for storage though as I want to put vacuum (CTL MIDI) inside to further reduce noise (always wanted to try that) and also connect it to router compartment for dust extraction.

However, I'm not sure about what material to use for the working surface.
Ply wood laminated with plastic for easy movement or solid wood that can be reconditioned when needed with a hand plane and an oil finish?
I already have hand tools solid and heavy workbench in my apartment. And I like that I can always clean it. Though the wood does move a bit.

On the other hand, to make that torsion box flat is not an easy task as it seems. A lot depends on how you glue it - a bit more clamping force in one place then others and it is not flat. Then when it screwed to the rest it can move yet again. Maybe if I glue it clamped downwards on my hand tools workbench it will be flat...

i was lucky enough to laminate half inch birch ply flat clamped to my cnc table, i know its dead flat, not sure how you could guarantee flatness without a reference surface

 

[thikone]

That high pressure laminate stuff is fantastic. I have it on my current workbench and it’s super hard wearing and very easily cleanable. Glue spills can be scraped off with a blunt chisel.

It would also be an ideal surface for a router table. Workpieces glide over it like butter.

I’d be wary of using it for a bench you’ll use for work holding though. What makes it great for a router table makes it a nightmare for work holding. Even clamping work down to the surface it can slip around unless you use tons of pressure.

Thanks for this information, didn't think of that... So maybe that is only good for router table side and then MDF or wood on the other side? Or even incorporate that MFT table top only, like drop in replaceable part...

Still not sure how to drill the holes though. I was hoping to use Peter Millard approach with LR32 rail and a router but with Bosch equivalent (FSN RA 32 rail). But then which router bit? It seems that not all of them produce the right diameter hole for the tide fit... but oversized or undersized.

 

[thikone]

i was lucky enough to laminate half inch birch ply flat clamped to my cnc table, i know its dead flat, not sure how you could guarantee flatness without a reference surface

Sure, my workbench is my reference surface. That's why I also use it for glue ups. Flattened it with #7 hand plane, slightly concave in the middle, like a shaving deep.

But I saw a video where just cutting straight ribs with a rail guide for torsion box was not enough - it was noticeably concave (a few mm) because of over clamping in the middle...

 

[Jacob]

Sure, my workbench is my reference surface. That's why I also use it for glue ups. Flattened it with #7 hand plane, slightly concave in the middle, like a shaving deep.

But I saw a video where just cutting straight ribs with a rail guide for torsion box was not enough - it was noticeably concave (a few mm) because of over clamping in the middle...

"reference surface" is an engineering term which has crept in to woodworking only recently.
The woodworkers "reference surface" is usually the workpiece itself, which you check by eye, or with winding sticks etc. No need for a special surface, though a flattish bench is not a bad idea.

 

[Spectric]

The main thing for me though is that an mft-style table would be a real help.

To get the best of both you could use top inserts, if you need the MFT then drop in the inserts with 20mm holes otherwise drop in solid inserts so now nothing falls through. I would be tempted to keep the section with the apron and top fixed though as this is ensures alignment between the vertical and horizontal.

 

[thikone]

"reference surface" is an engineering term which has crept in to woodworking only recently.
The woodworkers "reference surface" is usually the workpiece itself, which you check by eye, or with winding sticks etc. No need for a special surface, though a flattish bench is not a bad idea.

Yes, Jacob, you right. I've heard of course about winding sticks and I do check by eye (and by hand) too. If only it were from wood I would make it flat after gluing it together. But since it is plywood with plastic layer on top it requires different approach, unfortunately.

Actually, I like my flat bench so much that I never needed winding sticks - just clean the dust, put it upside down and see where it rocks.

 

[HamsterJam]

I do also repairs on electronics and such on my bench and it is very hard to find a small screw if it falls through the holes...

…….So maybe I will cover all of them and remove only when needed.

I have a similar issue and get around it by putting a sheet of ply, MDF or corrugated cardboard (whatever is to hand) on top of my MFT top when dealing with small screws etc.
I also keep a magnetic dish and some small plastic tubs handy plus a larger magnet in case I need to go fishing under the workbench.

 

[Calum Bettison]

An update here of where I’m at with the bench.

After building the frame I drilled 19mm holes in the feet for some proper hefty threaded inserts. These are to house adjustable feet so I can level the bench on my particularly uneven workshop floor.

These were the biggest inserts I could find (got them from a glazing company). They’re 40mm long and take an m12 thread.

 

[Calum Bettison]

Next job was to plane and laminate the beech for the trad side of the bench top.

I ripped down a couple of big boards into 105mm rips, planed and thicknessed to 38mm(ish) and laminated them up.

I decided against using biscuits or dominoes for alignment. The reason being, after I ripped the boards down, the tension in the beech curved the newly cut staves quite a bit. So I let the staves acclimatise in my space for a couple of weeks and just glued them without fighting their natural curvature. My thinking was that I’m not introducing any unnecessary tension into the staves.

You can see in the zoomed in photo how the staves don’t sit flush with each other.

 

[Calum Bettison]

After that was a sh*t load of hand planing. Fun and exhausting.

After a couple of days solid I got the new slab flat and square.

Before glue up I made sure that the grain of all the staves was pointing in the same direction, so that when planing I wouldn’t encounter any opposing grain from one stave to the next.

I then trimmed the ends with the track saw by doing a full depth cut, flipping it over and doing the same again.

 

[Calum Bettison]

Next step was to attach the slab to the frame. I used the same threaded inserts as I did for the feet.

I had to order a hefty hex bit for the driver from Amazon. Was about a tenner I think.

The top is attached with 150mm m12 bolts that go through the top. The ones on the edge of the bench are sat within a 12.5mm hole, the ones in the middle of the bench go through a 16mm hole. This is to allow for expansion and contraction of the beech.

It’s not supposed to look fancy and floating. That was a kind of side effect of the fixing method!

The beech is sandwiched between the bolt head, washers and by two locking nuts underneath that I can tighten against each other so I can adjust it the correct height (level with the MFT-to be).

The bolts that go through the 16mm holes (middle of the bench) have two washers so that they can slide over each other with the woods expansion.

 

[Calum Bettison]

With that in place I started on the MFT torsion box.

At this point it would be lovely if we could all get into a debate about what a torsion box is or isn’t

I made the beech side first so I had a perfectly flat surface to use for assembling and gluing the MFT carcass.

I ripped a bunch of MDF ribs down and glued them in pairs. These 36mm ribs will ‘contain’ the 20mm dog holes.

 

[paulrbarnard]

With that in place I started on the MFT torsion box.

At this point it would be lovely if we could all get into a debate about what a torsion box is or isn’t

I made the beech side first so I had a perfectly flat surface to use for assembling and gluing the MFT carcass.

I ripped a bunch of MDF ribs down and glued them in pairs. These 36mm ribs will ‘contain’ the 20mm dog holes.

View attachment 178674View attachment 178675

Maybe jumping the gun but no idea what the glued up pairs of MDF are for. You say the dog holes will go into them but that will make them too thick to get a clamp through.

 

[Calum Bettison]

On top of the carcass base, using spacers I lined up the ribs then glued and pocket-hole screwed them down.

Before drilling and screwing I marked out the position of all the dog holes so that I wouldn’t crash into any screws while drilling the 20mm holes.

 

[Calum Bettison]

Maybe jumping the gun but no idea what the glued up pairs of MDF are for. You say the dog holes will go into them but that will make them too thick to get a clamp through.

For rigidity really, I plan on using the cam action holdfast style or dog hole clamps rather than the f clamps.

To be honest this side of the bench is a bit of an experiment!

 

[Calum Bettison]

Where the box will be bolted down I’ve added in some material to house the bolt hole.

 

[Calum Bettison]

With the body of the carcass made I marked out and screwed down the lid.

I also drilled out the holes for the bolts.

I planed and sanded the sides then gave the edges a 3mm roundover.

 

[Calum Bettison]

Next I added the threaded inserts to the frame for the MFT side.

I made a template for these positions on a piece of hardboard, so that they would register perfectly with the bolt holes in the MFT.

When driving in the inserts I squirted some silicone lube in there. Even on highest setting the impact driver had a job getting them in there.