MFT and Rail Square - my thoughts

[Molynoox]

Wow, that's some write-up of possible configurations! I'll confess to skimming a good whack of it as I have myself covered.

There's one that I don't think is in there though: rail square mounted on MFT hinge with optional side stop. That's how my proper MFT rolls these days. The main benefit is that it takes the faff out of aligning a hinged rail to the dog holes as the rail and fence are one piece.
This only comes in to play once you've broken a sheet down and, with a side stop fitted, you're limited by the length of the piece the stop runs on; so it's not perfect by any means.

That's interesting, certainly hadn't thought of that one.
Is the faff setting up the hinge not a one time only event though?

 

[Spectric]

A good thought process @Molynoox and for me it highlights that the hinge is really a fancy extra, if you look at your setup but add the clips then it does what the hinge can do except you have to slide your work through. I think the biggest advantage of the hinge is that you have no dogs so nothing to cause obstruction.

Another option I do not hink you have included is the benchdog rail square with dogs screwed into it so now in essence you have a bench dogs hinge system that does not hinge. I think that when the Festool MFT bench and hinge first came out it was something that gave people an easy option for cutting but now with rail squares and parallel guides you have so many other options as you have explored.

 

[Molynoox]

A good thought process @Molynoox and for me it highlights that the hinge is really a fancy extra, if you look at your setup but add the clips then it does what the hinge can do except you have to slide your work through. I think the biggest advantage of the hinge is that you have no dogs so nothing to cause obstruction.

View attachment 156436

Another option I do not hink you have included is the benchdog rail square with dogs screwed into it so now in essence you have a bench dogs hinge system that does not hinge. I think that when the Festool MFT bench and hinge first came out it was something that gave people an easy option for cutting but now with rail squares and parallel guides you have so many other options as you have explored.

Yeah I agree, lots of options out there now, and also the hinges are becoming more accessible now with other companies doing their own versions and of course the option to DIY your own.

I think the extra setup you mention is my option 2?

 

[Nelsun]

That's interesting, certainly hadn't thought of that one.
Is the faff setting up the hinge not a one time only event though?

It's not a one time event in that I've flipped / swapped tops and had the hinge off for transportation often enough. It's not a common event by any means but I've caught myself out [edit: after reassembling] with hinge slop (even with a slop stop thing fitted) and misaligning things. This way I really can't muck things up... although I'm sure I'll find a way... somehow

 

[baldkev]

Heres a thought. I read the setup options box and thought the 3m x 1.5 would be useful, then thought I could domino on a couple of tabs of mdf, say 100mm wide and on opposite sides of a sheet and using the jig, route matching holes, therefore extending the crosscut to a full sheet off the dogs, or have a rail fitted one side and the tabs on the other side, 1 x 400mm from each end and one centrally?

 

[Molynoox]

Heres a thought. I read the setup options box and thought the 3m x 1.5 would be useful, then thought I could domino on a couple of tabs of mdf, say 100mm wide and on opposite sides of a sheet and using the jig, route matching holes, therefore extending the crosscut to a full sheet off the dogs, or have a rail fitted one side and the tabs on the other side, 1 x 400mm from each end and one centrally?

Nope, didn't understand any of that

 

[baldkev]

Nope, didn't understand any of that

Hopefully the drawing is more illustrative...... in doing so i changed the design a bit. The additional tabs could be located using a 2nd thickness, which goes under the mft, located with 20mm dowels and maybe pinned with a screw? This would ensure correct alignment and easily removed

 

[Molynoox]

ok got it.
If doing that, why not just have a slightly larger top to being with? Or are you talking about doing a retrospective extension of a standard 718mm MFT? If so then it could be a good route if you need more than 550mm crosscut and don't want to use a a hinge or a rail square

Martin

 

[Molynoox]

It's not a one time event in that I've flipped / swapped tops and had the hinge off for transportation often enough. It's not a common event by any means but I've caught myself out [edit: after reassembling] with hinge slop (even with a slop stop thing fitted) and misaligning things. This way I really can't muck things up... although I'm sure I'll find a way... somehow

aaah OK
Do you want to sell your hinge?

 

[baldkev]

ok got it.
If doing that, why not just have a slightly larger top to being with? Or are you talking about doing a retrospective extension of a standard 718mm MFT? If so then it could be a good route if you need more than 550mm crosscut and don't want to use a a hinge or a rail square

Martin

Yes, retrospective add ons i probably wont 'need' this as I'll mark a width or length and trim it, but if i really wanted to crosscut a full sheet regularly, it would be an option

 

[Molynoox]

Yes, retrospective add ons i probably wont 'need' this as I'll mark a width or length and trim it, but if i really wanted to crosscut a full sheet regularly, it would be an option

Is this for your gigantic 8x4 MFT you have just made?

 

[baldkev]

As my above post, i probably wont need it, but it was a thought that occurred to me after reading your 3m x 1.5m entry in the options box. Not many people would have the room for that, but even the small mft tables could benefit from extra capacity, especially if it can slot on and off. I might make them to test drive it, could be a handy addition.....

 

[Molynoox]

As my above post, i probably wont need it, but it was a thought that occurred to me after reading your 3m x 1.5m entry in the options box. Not many people would have the room for that, but even the small mft tables could benefit from extra capacity, especially if it can slot on and off. I might make them to test drive it, could be a handy addition.....

Yup, it would be handy and like you say it means you don't have to have a huge table in your workshop taking up space and getting in the way just for the odd occasion that you need more capacity - you can adapt the table to the needs of the day.

Martin

 

[space.dandy]

Anyway, I measured the accuracy of the rail square using my setup as 0.6mm for every 640mm of crosscut. Here are some pictures showing how I measured that:

First I checked that the rail square was exactly 90

The only problem I see here is that you are measuring from a reference that you haven’t verified. I don’t see anywhere in your text where you’ve checked that the left hand edge is also perfectly 90 degrees.

 

[Molynoox]

The only problem I see here is that you are measuring from a reference that you haven’t verified. I don’t see anywhere in your text where you’ve checked that the left hand edge is also perfectly 90 degrees.

I thought I explained it but maybe not. I used method 1s to trim the left hand edge of the board against the dogs which are known references.
I then flipped the board so that the perfect corner was at bottom left ready for the track square cuts

Martin

 

[paulrbarnard]

I thought I explained it but maybe not. I used method 1s to trim the left hand edge of the board against the dogs which are known references.
I then flipped the board so that the perfect corner was at bottom left ready for the track square cuts

Martin

The only way to be sure is the five cut method. That can be used to verify your dog holes and dogs.

 

[Molynoox]

The only way to be sure is the five cut method. That can be used to verify your dog holes and dogs.

I've just assumed the dog holes to be spot on, so maybe you are right I need to do a five cut and check it

Martin

 

[Doug71]

The 5 cut method is a great way to spend a couple of hours frustrating the **** out of yourself as you chase an impossible level of accuracy

It's one thing on a panel saw where you can adjust things but guess on an MFT it's either square or not?

Will you be checking every hole?

 

[Molynoox]

The 5 cut method is a great way to spend a couple of hours frustrating the **** out of yourself as you chase an impossible level of accuracy

It's one thing on a panel saw where you can adjust things but guess on an MFT it's either square or not?

Will you be checking every hole?

Lol good point about checking every hole
I will probably never get around to it; as I say, I've already 'assumed' the CNC manufactured MFT top to be spot on anyway and if it's out I'm sure I will be notified by all the wonky creations I churn out using it.

 

[pe2dave]

I've just assumed the dog holes to be spot on, so maybe you are right I need to do a five cut and check it

Martin

No, not necessary. Various methods to check. Easiest, measure diagonals for equality.