Thread: A Real Workshop

Great thinking! I guess I don't really need 20mm on the whole length but if the two 20mm holes were a bit closer together, say hole 1 and hole 4, it also enables me to use the template on narrower material in future.

My postcode is 5014, but I am happy to have it picked up from you by sendle.com whose rates are probably even better than Auspost and it saves you the hassle of going to the post office with it. Cheers

Originally Posted by rev

Agreed Ian.

Here is another bit that might fit the bill properly and not too expensive:
Arden Metric Bottom Cleaning Router Bits 1 2 20mm 1 2 Shank 1 2×20MM×20MM BIT | eBay

Given the precision you need for the MFT equivalent to function as intended -- a true 90 degree grid -- I consider the cost of the required router bit to be insignificant. There's no point in saving $60 on the bit, if the resulting grid is either sloppy -- I've read (via google searching) that one of the Festool 20mm cutters produces a 20.2mm hole -- or inaccurate.
Perhaps, the cutter needs to be something like this

http://www.cmtutensili.com/show_item...=TB~513%20HW~2

pippin88

my top is 2400mm long and a bit under 600 wide.
I can only get 5 holes wide.

If you cut my Template 600mm wide I could have the full width of 5 holes.

I like the idea of having some 20mm holes for re-locating the jig.

My brain can't work out the best place to locate them. But I think Rev's suggestion of 20mm holes in each corner and halfway between them makes sense.

Saturday would be great. I can come over anytime that suits you.

Ian
The boring tool should be the most accurate.
I had a look at the CMT bits but they look like they are drill bits.
I can't see how you would be able to drill dead straight holes with a hand held drill.

I read that some of the bench dogs for the MFT were too tight a fit. They now make them very slightly undersized. The lip on the Qwas dogs stops them falling through the holes.

When you think about it, we will have a router, router bit, template and a timber board, each with an opportunity for an error.
There will always be some error.
The greater the distance between two dog holes the smaller the percentage will be.
So as long as we are aware of the small error we can adjust for it.

All we can do is minimise the error with each step.

20.2mm for the Festool cutter sounds like a very large error. I hope we can do better than that.

Scally,

Having a quick look, I figure you could have 6 holes by 25 holes on a 240x60cm bench.

Scally.jpg

That would leave 38mm from each end to edge of first hole (48mm to centre) and 50mm (60 centre) front and back.

25 holes long would require two template moves (3 setups) unfortunately.

If you are happy with 24 holes along the edge, it would be 96mm from end to first hole centre.
You could do the whole grid with one template move (2 setups) in this case.

Scally24_1.jpgScally24_2.jpg



What is your preference?
Confirming the 1 3/8" bushing (34.925mm)?

Yes the template size sounds good. One template move would certainly minimise errors caused by several moves.
I have bought metal 20mm bench dogs and have Festool bench dog clamps. They should give me a tight fit when moving the template for the second setup.

I checked my bushing with two different verniers.
The bushing is slightly oval.

The maximum diameter is 34.90mm.

Yes the template size sounds good. One template move would certainly minimise errors caused by several moves.
I have bought metal 20mm bench dogs and have Festool bench dog clamps. They should give me a tight fit when moving the template for the second setup.

I checked my bushing with two different verniers.
The bushing is slightly oval.

The maximum diameter is 34.90mm.

Originally Posted by Scally

20.2mm for the Festool cutter sounds like a very large error. I hope we can do better than that.

20.2 instead of 20.0 represents an error of 1% -- which doesn't sound like much.

the maximum error would be 0.4 (0.2 "left" plus 0.2 "right") which is 4 parts in 1000 for adjacent holes, and 1 part in 1450 across the depth of your bench

Would the festool zobo forstner bit make life simpler?

Link Here


Ideal tools sell a 20mm version

Ideal Link Here

For anyone else who might be looking at doing this sort of thing:

- There's a ton of info from people who've done it already on Festool Owner's Group

- I believe the best bit for the job is the Festool 20mm Hinge Boring Bit. Not cheap at all, but an excellent bit. I wasn't in a hurry, so saved some $$ by getting it from overseas

- I used my workbench project as an excuse to buy the Festool LR32 shelf pin kit. If you can foresee other uses for the kit, don't hesitate - it's brilliant, and makes very easy work of accurately boring the bench top.

Originally Posted by pippin88

Having a quick look, I figure you could have 6 holes by 25 holes on a 240x60cm bench.

Scally.jpg

That would leave 38mm from each end to edge of first hole (48mm to centre) and 50mm (60 centre) front and back.

25 holes long would require two template moves (3 setups) unfortunately.

If you are happy with 24 holes along the edge, it would be 96mm from end to first hole centre.
You could do the whole grid with one template move (2 setups) in this case.

Scally24_1.jpgScally24_2.jpg

Just a thought ...

If the template is initially placed to drill the holes in the center of the bench, then effectively, the template only moves once.
once to the right, indexed off the center group of holes, and
once to the left, again indexed off the center group of holes.

any error due to miss-aligning the template would be halved, and also would only effect the holes at each end of the bench

I now have a CNC made MFT template thanks to pippin88.

First the six 20mm holes were made along one edge. Initially the holes were made undersized then the diameter was increased until the fit was snug.

These will be used to locate the template to drill the second set of cuts.

Then pippin88 went through the same process to custom fit my 1 3/8th inch bushing to create the rest of the template.
He milled all the holes slightly under sized the did a finish cut at the custom fit.

The fit is pretty tight. There is just enough play to get the bushing in and out without much force.

It should allow me to make very accurate MFT style bench tops.

We were at it for a couple of hours. A bit of time discussing tolerance of the fittings.
Then a fair bit more time talking about important woodworking things.

The CNC machine was very smooth and took very little time to mill the complete template.

Great job pippin88. Much appreciated.

well done pippin88

I set the template on my film ply top and decided where I wanted the holes near the edge.

I put a screw in at each end to hold the template firmly in place.
A few more would probably be a good idea because it took a bit of jiggling getting the router bushing out of the template holes.

First I did all the holes with a 12mm spiral bit. It plunged easily through the dense filmply.
The router blew most of the sawdust out of the holes but I gave it a vacuum after the whole sheet was routed.
Then I changed over to the 20mm router bit. It plunged easily to finish the holes.
I tried the 20mm bit without the 12mm spiral pilot hole. It didn't like it much.

After all the holes had been routed to 20mm I removed the template and checked the fit of the dog holes.

The holes were very neat with minimal tearout.

The dogs fitted easily but are probably a bit looser than I had hoped.
I am sure they will work fine.

Next step is to flip the template to finish the bench top.