New to MFT Style Work Table

[Mike Goetzke]

I previously owned almost everything Eurekazone had to offer – including an EZ-One bench. We’ll, I’m getting older now and didn’t want to mess around adjusting things as much as I used them. So about a year ago I decided to sell/give-away almost all of my EZ and purchase a Makita cordless track saw kit that came with a 55” rail, 4-batteries, and added a 118” rail. For extra depth of cut I also picked up a TS75 that came with  a 75” rail.

Now that I moved from EZ I started visiting the FOG more often. The MFT benches perked my interest since I was used to working off my EZ-One but they seemed a little on the small size. Plus I need something that can easily be assembled and knocked down and stored.

I became determined to make a multi-slab bench.

I have two Kreg Mobile Project Stations (fancy sawhorses) that I use quite often even for non-woodworking projects. I was wondering if others had designed slab tops to go between two of these.

Sure enough I found what I was looking for on the Kreg user forum – TrackTubes! You can search them on the FOG too but they are basically an aluminum extruded 2x4 with a t-track on the top. I bought a set of 90” long tubes.

I decided to go with three tops 32”x48” so I could have either a 32”x96” two slab table or 48”x96” three slab table. Plus you can get all three from one 4’x8’ sheet of MDF.

Looked over many-many MFT type slab designs, made several iterations myself with my simple 2-D CAD program, and finally came up with something that I hope would work well for cutting, assembly, and my other projects.

Was set to purchase the Parf drilling system but they were out-of-stock and wouldn’t be available for some time I started looking for a local CNC router supplier. Many suggest going this rout anyway. I found one less than a mile from my house.

I’m new to working on an MFT style table and have some questions:

Hole size??? Found many suggestions and drew them up as 20.1mm (0.791”) but my CNC guy was kind enough to bore six holes in decreasing diameters of 0.oo1” since the 0.0791” was too loose for the dogs. Ends up 0.787” worked best for my dogs and his machine (snug fit yet could be removed).

Seal Top??? I see some use poly/Waterlox/Shellac  then wax it. Suggestions here appreciated.

Edge Banding??? My tops will be removed and then stored on a cable lift rack. Should I edge band them with wood?

Kerf cut through top or not??? Some just cut through some say they used a thing sheet stock underneath to prevent cutting the top and some seem to use foam board. Like to hear from experienced users what they like best.

Cutting Guides??? I recently purchased a TSO GRS-16 PE. I also have a parallel edge guide for the this square. With the MFT style top would you: use the square/parallel edge guide, bench dogs, or combination of both?

Thanks,
Mike

 

[nclemmons]

Welcome to FOG! 

I think your approach with lightweight MDF for the tops cut with a CNC is a good way to go. Some have included a couple of handholds routed into the top for easy handling, so that might be a consideration.

You can edge band them if you are moving them a lot and concerned about the edges getting bunged up.  Or consider them 'replaceable' and as they wear, get cut, etc, just get new ones cut given you have  CNC available close by.

I like the bench dogs idea for consistent cutting with a lot of flexibility.  Check out TSO's website for their double groove tall dogs and dog rail clips that work really well for using the rail with dogs and keeping it indexed and tight.  Those tall dogs when combined with two short dogs give you a good repeatable setup for square cuts.  Since you are going to be moving the tops for teardown, I don't think I'd trust the edge for consistently square cuts and the dogs can do a great job for you.  TSO offers the tall dogs in two diameters, so you may want to check your dimensions on the holes to get the right fit from them.

I've never sealed my MFT top.  I occasionally will hit it with 150-180 grit sandpaper to remove glue or other imperfections and it's worked well with no sealing.  If I was to seal it, I'd probably just use wax.  But personally I like a little friction to keep the wood from slipping on the top.

I have a kerf cut in mine given I have the rail and clamps from Festool on my MFT.  Some users here on FOG cut everywhere on their tops.  I have tended to cut within the one spot.  And it works fine.  You can in time choose to fill that kerf with bondo or similar filler.  Or route out a replaceable insert.  Or just replace the top.  Your call as they are all workable options.

I do use foam at times for larger pieces than will fit on my table - full sheet cutdown for example, and really like that as an option when the table is too small.  Since you have the TSO rail square, it works great with the foam under the cut.  My foam is cut into 2x4" pieces which also let me lay on the MFT table if I have some odd cuts I want to do, or even through routing.

Good luck and share some work as you move forward.  I'd also like to hear how you like the Makita cordless saw versus the Festool TS75 in terms of handling, etc. 

 

[Klemm]

[member=4518]Mike Goetzke[/member] - let me chine in about hole size in bench tops:
If  you expect to use commercially available Dogs like TSO's or Parf Super Dog you may want to consider the ramifications of dimensions and tolerances.

The .787" you mention = 19.98mm for your CNC routed benchtop is likely to make it very hard to insert and extract some Dogs like Parf Super Dogs or TSO CF-Dogs which are designed for a very Close Fit as the name implies(approaching interference fit on a .787" dia hole).

You may want to reconsider going that tight. If you do, you may want to specify our standard Dogs.

Hans

Mesauring the I.D. of a hole, as I have seen attempted on other FOG threads, really has its limits when it comes to accuracy. If you really want to know the diameter of a specific hole, a pin gage is the way to go.

 

[Mike Goetzke]

[member=59331]TSO Products[/member]    and others

Best hole drilling size for shop made MFT tops is hard to find - I researched quite a bit. What I heard from a few was to bring your bench dogs with and test the holes. Guess this is equivalent to the "pin" gauge you mention.

My dogs measured consistently between 19.89mm and 19.9mm. I was going to have 20.10mm holes bored but CNC guy suggested I bring a scrap board to test. Good thing I did the dog was way too loose. I chose the hole that I used little effort to insert and could remove easily (it wouldn't fall out on it's own). Was this the correct way to choose the hole by fit (or should they drop into the hole under its own weight)?

Not contesting your reply but trying to get educated. My 0.787" happens to translates to 20.00mm - just happens to be the size I chose by fit. Don't know if the CNC'd hole was actually 0.787" that's just what he punched into his machine.  What are the true sizes of 20mm drill, 20mm router bit, and 20mm boring bit? Many use these tools to bore the holes. I read someone used pin gauges to measure his MFT/3 and found out the unused holes were 20.00mm and worn ones 20.10mm.

My mind doesn't think in metric but if you had 20.10mm holes and 19.90mm dogs the diametrical tolerance would be 0.008". This seems to be loose when looking at ISO fit standards. Think in my case I had the dogs and tested it in the hole so I eliminated most of the tolerance error in the fit. I can still change the size but think I'd rather have to adjust a few dogs than to have too loose of a fit.

Mike

 

[cubevandude]

I’m new to working on an MFT style table and have some questions:

Hole size??? Found many suggestions and drew them up as 20.1mm (0.791”) but my CNC guy was kind enough to bore six holes in decreasing diameters of 0.oo1” since the 0.0791” was too loose for the dogs. Ends up 0.787” worked best for my dogs and his machine (snug fit yet could be removed).

Seal Top??? I see some use poly/Waterlox/Shellac  then wax it. Suggestions here appreciated.

Edge Banding??? My tops will be removed and then stored on a cable lift rack. Should I edge band them with wood?

Kerf cut through top or not??? Some just cut through some say they used a thing sheet stock underneath to prevent cutting the top and some seem to use foam board. Like to hear from experienced users what they like best.

Cutting Guides??? I recently purchased a TSO GRS-16 PE. I also have a parallel edge guide for the this square. With the MFT style top would you: use the square/parallel edge guide, bench dogs, or combination of both?

Hi Mike,
I have the 1st generation UJK Parf guide system for drilling my tops.
Hole size - Sounds like you have the right size to me.  You might think of chamfering the holes and this will help in removing the dogs.  I use a router and 45 degree chamfer bit.
Seal Top- I seal my tops with a least 2 coats of polyurethane before I drill my holes.  You might be able to wax the dog holes themselves, but I haven't gotten around to trying this yet.
Edge Banding - Not sure what you have in mind for this.  A frame would help keep the top from warping.
Kerf Cut - I try not to cut into my tops if I can help it.  I have seen centipede non-slip pads used to keep your work above the top.  I think this is a great idea and am trying to find some myself.
Cutting Guides - I use the UJK Technology Parf Dog Rail Clips when using the dog holes.  Your guide could be used when not using the dog holes in the top.

 

[Mike Goetzke]

[member=60014]cubevandude[/member]  thanks for the info. With the centipede pads  - do you just place them under the work piece for elevated support?

Picked up my three tops today - my Veritas parf dogs fit well. They almost drop in on their own and pull out easily. After using a dog hole they seem to become smoother.

I couldn't wait to put the slabs on my TrackTubes. Attached an image of the three tops side by side:

 

[cubevandude]

[member=60014]cubevandude[/member]  thanks for the info. With the centipede pads  - do you just place them under the work piece for elevated support?

Yes.  Check out the video here:https://www.xtools.se/sv-SE/sortiment/mft-bord-bänke-38227270

 

[TealaG]

Definitely seal that MDF or you will have regret!  I used 3 coats of polycrylic, but that's because I had on hand and I needed to use it up.  Naked (without sealer) wasn't pretty.  Don't do it!  I think almost any sealer is better than none. 

Also, I would round over or do a slight champfer on those slots and maybe the holes too.  Otherwise, it looks REAL good. 

Cutting into the board is a personal choice.  I have had kickback issues with my "randomly positioned" scrap plywood boards (ie the slots aren't straight, they were angled etc and I think that depending on the way the wood was turned, the blade sometimes pinched when the blade was too deep).  I think, theoretically, raising the board may not give you as good a result as cutting into the board below because the board you're cutting doesn't have support and may have more tear out than if you cut into the board.  I've seen many options, such as a replaceable spoil board.  At this point, I'm still using my crappy, cut up plywood.  But I want to add my Festool track holder (the thing that hinges the track up), which will make it more difficult to move it around and therefore, I might use a replaceable spoilboard under that area.  The cuts would be straight and all along the same line thereby fixing my kickback issue.  I think the board could be rotated (similar to replaceable inserts for a drill press) before replacing.