Advice on using an MFT to cut full sheets

[mikej460]

Although only in the planning stage I'm considering how to cut full sheets of OSB then birch ply accurately and efficiently for my new 30m2 workshop. I'd rather not resort to my current system of circular saw and clamp rail as it takes far too long to setup; I own a Triton Track Saw and 2 x 1.4m Evolution rail set , so I'm considering a MFT setup using MFT top(s) fixed to 2 x 100mm rails supported on my Toughbuilt C700 sawhorses. What is the simplest, most efficient and stable setup, bearing in mind the evolution rails really need supporting? e.g. Rail Square and/or bench dogs? Fence system? Track quick clamps? The myriad of options is sending me spinning like a demented darlek.

As I see it the simplest setup would be to use a combination of bench dogs and one or both rails, in which case for cross cuts using just bench dogs any top would need at least one row of holes clear of either side of the sheet to be cut. I can't see how a fence system would be useful for the OSB sheets but would be useful when making the birch ply cleat system and drawer units later this year - unless I'm missing something? Once my addled brain is settled on this then I need to consider how I make the top:

1. Using a combination of CNC's MFT/3-LP tops (L)1102 x (W) 718 mm x (D) 18 mm. This would require noggins between the two main rails or
2. Make my own with an UKJ Parf Guide System

I've watched Peter Millard's 10 minute workshop vids and a few others but would appreciate any advice from the forum.

Many thanks

Mike

 

[mikej460]

I posted this really late last night so not sure if it's dropped off the new post list before anyone could reply.

 

[marcros]

What are you wanting to cut and what are you wanting to produce? Do you need repeat cuts? Is it a task that you will do regularly, or after fitting out the workshop will the need diminish?

I don't generally cut full sheets because I can't get them home! I use some Stanley sawhorses and an mft top when I process car sized lumps.

 

[porker]

Personally I wouldn't break down full sheets using an MFT. I have a sort of Ron Paulk type table which is roughly the size of an MFT but it is too small for full sheets. I put full sheets on a cutting table with a sheet of insulating foam underneath to support the sheet. I would then either use parallel guides (mine are home made) or measure and lay the rails on for the cut. Parallel guides are useful for this for repeat cuts.

I use the MFT once the pieces are more manageable

 

[HDC83]

Personally I wouldn't break down full sheets using an MFT. I have a sort of Ron Paulk type table which is roughly the size of an MFT but it is too small for full sheets. I put full sheets on a cutting table with a sheet of insulating foam underneath to support the sheet. I would then either use parallel guides (mine are home made) or measure and lay the rails on for the cut. Parallel guides are useful for this for repeat cuts.

I use the MFT once the pieces are more manageable

I agree, I use a cutting table and parallel guides I made, then use a MFT. Also use rail square to square up ends of full sheets after cutting roughly 10mm off the factory edge for say cladding studwork ect.

 

[LJM]

The latest iteration of the Paulk workstation uses simple extensions to enable a small table handle full sheets and them to be processed exactly as you would smaller pieces on a standard MFT (or similar). Might suit your needs.

 

[robgul]

Personally I wouldn't break down full sheets using an MFT. I have a sort of Ron Paulk type table which is roughly the size of an MFT but it is too small for full sheets. I put full sheets on a cutting table with a sheet of insulating foam underneath to support the sheet. I would then either use parallel guides (mine are home made) or measure and lay the rails on for the cut. Parallel guides are useful for this for repeat cuts.

I use the MFT once the pieces are more manageable

Ditto - I often get the timber supplier to put his saw through full sheets to get them home, and be able to store them - a bit of thinking on the project and cuts is required.

For large sheets I have a pair of saw-horses and custom top that lets me position a guide rail and then cut with a hand circular saw, or sometimes the track saw. The saw horse cutting only when it's not raining as I have to do that outside!

 

[mikej460]

The sheets will be delivered full size for the walls and roof. The sheets will be laid horizontally so at best I will need to rip the last row along the long edge and probably cross cut all the last sheets in each row. At worst all of them will need to be cross cut (dependent on the final choice of insulation and commensurate stud spacing. I've now found this video which is pretty much what I need, although I don't need the bench as I will use my saw horses:



This is the simplest and probably cheapest setup as I just need the MFT top(s) and bench dogs. I can then improve on it for dimensioning birch ply for the cleat system and drawer units later.

 

[DBT85]

I break down full sheets on my mft bench, but it's a standard mft depth but about twice as wide. Only the middle bit is actually an mft, the rest is just mrmdf. I don't bother putting anything under the sheet I'm breaking down so my workbench has 2mm deep scores in it.

The horror.

For cutting materials for the workshop build, I'd say a rail square is probably the easiest bet. I did all my osb sheets for the inside with my titan tracksaw on the floor and just measured either side and lined the track up as needed.

A rail square would have made it a little faster I guess. Didn't use the mft to do anything to actually make my workshop.

Out of interest why are you laying them landscape rather than portrait? And where is the build thread, have I missed it?

 

[mikej460]

I break down full sheets on my mft bench, but it's a standard mft depth but about twice as wide. Only the middle bit is actually an mft, the rest is just mrmdf. I don't bother putting anything under the sheet I'm breaking down so my workbench has 2mm deep scores in it.

The horror.

For cutting materials for the workshop build, I'd say a rail square is probably the easiest bet. I did all my osb sheets for the inside with my titan tracksaw on the floor and just measured either side and lined the track up as needed.

A rail square would have made it a little faster I guess. Didn't use the mft to do anything to actually make my workshop.

Out of interest why are you laying them landscape rather than portrait? And where is the build thread, have I missed it?

I'm not keen on joints showing (borderline OCD) I have it in my mind's eye that I can cover the single horizontal joint with the conduit run and the vertical joints with a moulded strip. I haven't started the build yet as I'm currently building a greenhouse for my wife but it's next on the list!

 

[Ollie78]

I just put a couple of battens on the floor and use the track saw. Don't get complicated.

Ollie

 

[NewbieRaf]

I have an mft but never cut full sheets on it just because if it’s size. The way I do it is using sheets of insulation on the floor. I lay the the track to rough cut to size, square it up with a regular square and make the cut. I then use the mft to cut accurately to size

hope this helps

 

[PeteBowen]

I just put a couple of battens on the floor and use the track saw. Don't get complicated.

Ollie

I did this when I cut the interior ply and OSB for my man-cave. Cutting to tape measure lines was accurate enough for building work because the framing isn't 100% accurate.

 

[eribaMotters]

For one man dimensioning larger pieces of sheet material I use a cheap approach :-
- set up two sawing horses and lay 3 old lengths of lengths of 75 x 75 wooden fence posts on top.
- lay sheet material on top of these and mark out
- clamp straight edge, either off cut of sheet material or length of trespa as straight edge
- cut wit 10.8v cordless Makita circular saw, moving 75 x 75 timbers as needed
I can usually get 2 full cuts lengthways on an 18mm birch plywood sheet. The finish from the blade is so good it usually needs only a a stroke with a plane blade for a finished edge.

Colin

 

[pe2dave]

I had no difficulty cutting full sheets lengthways with 2 off 1.4m tracks. They didn't need anchoring. If the 'rubber' strips are clean also the board, they grip the wood sufficiently when cutting. My only suggestion would be a parallel guide to ensure you're (easily) accurate when cutting?

 

[DBT85]

I'm not keen on joints showing (borderline OCD) I have it in my mind's eye that I can cover the single horizontal joint with the conduit run and the vertical joints with a moulded strip. I haven't started the build yet as I'm currently building a greenhouse for my wife but it's next on the list!

A moulded strip?

If I'm honest Mike, if you don't want to see any joints then foil backed plasterboard it and go that way. The horizontal joint being covered with the conduit works fine so long as you want them at that height, but I'm not sure about a moulded strip for the verticals. Not even sure hat you mean .

Assuming you want to paint the OSB and you are as OCD about it not all being perfect, you'll need to spray it probably as OSB isn't a solid face so you will end up with dark spots wher no paint got in if you use a roller. At least I did. Didn't bother me. I have a feeling @Sheptonphil used plasterboard on his build but I don;t recall if he then just taped and painted or got it skimmed.

 

[mikej460]

A moulded strip?

If I'm honest Mike, if you don't want to see any joints then foil backed plasterboard it and go that way. The horizontal joint being covered with the conduit works fine so long as you want them at that height, but I'm not sure about a moulded strip for the verticals. Not even sure hat you mean .

Assuming you want to paint the OSB and you are as OCD about it not all being perfect, you'll need to spray it probably as OSB isn't a solid face so you will end up with dark spots wher no paint got in if you use a roller. At least I did. Didn't bother me. I have a feeling @Sheptonphil used plasterboard on his build but I don;t recall if he then just taped and painted or got it skimmed.

Who knows what goes on in my head I have an idea of the design I want but all this could change as I progress. I am one of those people that would get just as much enjoyment building and kitting out a workshop as I do making stuff, so the workshop aesthetics matter a lot. I do have a tendency to overthink things I want to build in a way that I can use some or all of it later, hence the idea of using bench dogs and MFT tops. However, I plan to build a new MFT workbench similar to @billw so the MFT tops may be discounted as an unnecessary expense. I am also conscious of budget as I have more pressing things to spend my money on over the coming months.

So for dimensioning full size OSB sheets I can clearly see that a rail square would be useful option for the build and for future sheet work. I did build a small parallel guide after watching Peter Millard's videos; it worked ok for dimensioning smaller sections of birch ply but it was thrown together with what material I had so it's not robust and I had intended to make a better one for the kitting out work. I will now have a think about how I can build one big enough to fit over my saw horse setup for full size sheets.

I'm not convinced on the option to use plasterboard as it's not as versatile as OSB for holding up a cleat system unless you get the studwork marked up but I'm not discounting it.

With everyone's advice bringing me back to earth, I'm getting closer to a decision. Thanks for the painting advice

 

[mikej460]

Here's an update:
I decided that kneeling on a damp garage floor was not that appealing so I made this knockdown dimensioning bench that I can use to build the frames for a new greenhouse and my new workshop as well as dimensioning sheets of OSB:

I already had the Toughbuilt trestles and bought four MFT tops from CNC Designs which are excellent quality and extremely well packaged. I built a frame from 2x4 then bought some UJK bench dogs from Axminster but they were rather loose in the MFT which was surprising as their website says they fit alternative mft's so I returned them (great service from Axminster) and bought a Quad Dog Systainer set from Bench Dogs, together with a set of Bench Protectors and Dog Collars, and I'm very pleased with them.

I wanted to use my 1.4m Evolution track for cross cutting but I've hit two problems:
The track doesn't support UJK Track Clips which is a real pain. I tried fitting them underneath but they pull the track slightly away from the bench dog.
The 1.4m track doesn't look long enough to give me enough room to plunge cut into the sheet - I haven't tried it yet but am I wrong?

Should I buy an expensive Festool 1.9m track to solve both these issues?

Another issue I would appreciate suggestions for is that a full sheet on the table leaves a gap between the far end dogs and the edge of the sheet. What is the best solution for this? The only one I've come up with so far is a strip of mrmdf.

 

[gog64]

1.4m track is tight for a cross cut, but perfectly doable. I’ve done a lot with my TS55. The only issues I have are trying to use any accessories that need just a little longer track. Also, buy a rail square, the Benchdogs one is great.

Because I’m the wrong side of 50 and still have to cut quite of sheet materials I bought an STM 1800 some time ago. Sounds a bit like what you’ve been trying to achieve, except it picks up sheets off the floor and carries them for you too. Expensive, worth it to me in time and back pain saving.

 

[DBT85]

It depends on the saw as well. The guides on my ts55 for example are longer than on my titan. A titan that's not wholly on the rail can waver a bit while the festool is a bit more lenient from what I've seen.

Mike, I'm not sure what your issue is about the sheet and the far end dogs? The edge of the sheet should be against 2 dogs while the rail should be against 2 dogs perpendicular to the ones for the sheet. You can of course use the rightmost one for the sheet for the rail as well.

This only works if the 4 mfts you've fitted are perfectly aligned with each other of course.

Another issue you might run into is the motor housing hitting the tall dogs bracing the rail. I tend to use shorter ones to avoid the annoyance.