Large format MFT Plans

[Neocleous]

Hi everyone,

I am hoping to move into a larger work space soon so I have started looking thinking about my new workbench.

I currently use an MFT and I love the functionality of it so I want to make a larger one with storage and a router table. I was inspired by the BF/MFT https://www.garagejournal.com/2019/10/the-bf-mft-workbench-build-part-1/ and the Woodgrafter to use the Incra fence, https://www.youtube.com/watch?v=QL9Xj0fFDeM.

As this isn't a cheap build I'd like to get peoples thoughts and opinions and any suggestions.

 

[Sideways]

If you have space for it, go for it !
I have two benches (much smaller than your proposed) assembled from a lighter weight what i'll call "8040" alloy extrusion. It's great stuff but stupidly expensive in the UK.
I have a 56Kg bench drill sat on the larger bench (about 1200 x 850mm) with about a dozen powertools in their cases on the bottom shelf the 2 surfaces are sheets of trespa, each weighs 10 to 15 kilos on their own - so in my opinion, the alloy is plenty strong enough, but I could pick and put the skeleton easily before I loaded it with the tops and payload.

Suggestions : Unless you have a dead flat floor, I'd avoid the castors. I don't consider this type of alloy super rigid against flex, nor do you want to make it flex. I'd have adjustable levelling feet screwed in where you have castors and I'd pick a spot for it and level it up in that place. If it has to move (occasionally) fit castors and levelling feet so that you can wind up the feet and roll it aside if you have to, but the frame's evenly supported when not being moved.
Secondly, although more expensive than drill through fixings, cast angle brackets with the matching T bolts and flange nuts are supposed to be the strongest and most ridgid way of jointing the alloy. I used them liberally. I have a mix of 8040 profile for the long sections and 4040 for the less stressed cross pieces and the legs.

 

[Neocleous]

Thanks for the comments, adjustable feet sound like a sensible idea. Ideal solution would be putting the brake on lowered a foot. Not sure if I’ll be able to find such a thing.

One of my concerns is that the top may sag with the weight of the router although it is well supported. I was thinking of securing the Incra on t tracks but I don’t have one to measure the plate spacing so I’m not sure if that is possible as I want to be able to move it.

I costed up the model after I posted it and the extrusion, foot plates and casters come to £617 from KJN so not cheap at all but should last a very long time. Are there any other UK suppliers of extrusion like this? It’s all 8040 and 4040.

I’ll take a look at the cast brackets I’m sure they’ll look better too but surely having three way joints at every vertical is weaker than a solid bottom piece?

 

[mbartlett99]

I've a similar set up in my workshop but with a wooden frame - its on braked wheels and just short of the full 8 x 4 size. It gets more use than my actual workbench and having the worlds largest router table comes in handy from time to time. So I'd say if you have the space its well worth it.

I've used the 40 x 40 t slot extrusions a lot at work and they're super strong and very stiff but don't undestimate the weight. Loads of suppliers although its never cheap; http://www.aluminium-profile.co.uk/acat ... ofile.html or http://www.motedis.co.uk/shop/Slot-prof ... 93455.html .

I used mdf for the top and it has sagged in the middle, if I can get some I'll be replacing with 24mm ply and using some 40/40 extrusion through bolted to add stiffness. The holes I'll be doing myself with a 3d printed jig.

I would think that the first of our links would be seriously heavy - not sure that'll be mobile possible as it were.

 

[Neocleous]

That’s good to know, I thought MDF might be a problem. I think I’ll switch to birch ply for the top and put two horizontal extrusions to support it.

 

[mbartlett99]

Thats what I'm planning on - if I can find birch ply which is a bit of an issue around here.

 

[transatlantic]

One thing to note with that kind of large router table design is that you really do have to take a lot more care in keeping it perfectly flat. Any small amount of sag will increase error when routing long pieces across such a long table.

It's a bit like a mitre station with extension fences on either side. Any small amount of bow in a long piece means you won't get a square cut, as the piece won't push up against the saw fence. Where as if you didn't have the extension fences, then your reference fence is much smaller, and you'll get a much more accurate square cut (locally to that section of the timber). So depending on the work you do, a big router table might not be the best option, unless you can get it properly flat.

I only have a small MFT station, but it has a router in it, and it has sagged, which has produced the issue I mentioned above. It's only really good for routing small pieces now. I'm going to replace it though and add supports underneath next time. Still not decided on MDF or Ply though. I think the dogs will fit much better into MDF, where as ply is more likely to chip over time. hmmm

 

[mbartlett99]

Absolutely. My router fence runs across the table - 1 metre long. What I'm thinking of is through bolting the two t tracks to 40mm extrusions which should hold the table flat either side of the router plate (I have one running across either side of the plate). Then using a length of L shaped extrusion as a fence. That stuff is seriously stiff.

 

[Sideways]

The idea of adding alloy stiffeners to the underside of the router table to combat sag seems very sensible to me. I'm always happy to copy good ideas. Here's how Jessem do it on one of their premium commercial tables.

I'd just run 8040 cross pieces below the table top, lined up between rows of dog holes. Alloy profile is great for it's flexibility to place the elements wherever you want them.

Pics for interest. I wanted access to the ends of the legs as these can be threaded and the feet screwed in. This is an inferior design to the one that started the thread, but it maximises the surface area and has still proven ample strong enough for my use.

Here is a single 8040 spar bolted to the underside of a DIY MFT top to reduce sag as also mentioned.

 

[DBT85]

If all I wanted was to stiffen the table like that I'd probably use steel angle because it's dirt cheap. Ally extrusion is so over priced because of the type of market its mostly sold to.

A metre of steel angle 25*25*5mm is about a tenner on ebay.

 

[mbartlett99]

40\40 is 12.78GBP - I wouldn't buy just for that though. The nice thing abut the ally is its dead straight everytime.

 

[transatlantic]

Just priced up how much it would cost to build a frame from 40x80 that would fit an MFT replacement top (1100x700mm).

top
2x 1100mm £44 (front and back rail)
2x 700mm £28 (sides)
1x 600mm £12 (middle rail for support)

legs
4x 800mm £64 (legs)
2x 500mm £20 (side rail supports)
1x 1000mm £20 (back rail)

and with £50 for the birch ply top, and say £20 for the hardware (nuts/bolts) and then shipping

£300ish :shock:

Aluminium profile for the top, and then wooden legs would be a good compromise, as you only really need the profile to keep the top flat. Probably looking more at the £200 mark then.