Hole size for home made MFT

[mhch]

  20mm PVC pipe is 1 USD a  2m pipe in the DIY
  store 10minute drive from my home which I visit
  regularly.

  It would be my pleasure to buy a number of these, cut them
  into 10 x 200mm sections, pack and ship some to a few
  destinations of your choice.  Not a big hassle.

  France to US, UPS standard shipping is around USD 15 and
  it seems that receiver can pay for it,

  Make your own  decision and setup a thread on this forum
  to organize the details, if interested.

 

[ken257]

I only just started getting Festools in January. My first purchase was a TS55, C12, and a OF1010. At the same time I ordered the guide rail accessory kit and clamping elements. I wanted to hold off on the MFT until the new version was available so in the meantime I planned on using a home made top. I was faced with the problem of how to make the holes at about 11PM. I did not want to wait for a mail order 20mm bit to arrive, nor pay for one. I dug in my junk bits and blades box and came up with a 7/8" wing bit that I ground down to make a 20mm bit. I did not measure, I just kept grinding a little at a time and drilling test holes until the clamping elements fit just right with a little bit of snugness. First I marked out the location of all the holes then using a drilling aid for a hand drill I made holes with a 1/8" bit. Next I drilled one side with the modified bit until I just scored the surface. Next I flipped the top over and finished the holes from the other side. This procedure eliminates blowout as the wing bit exits the other side without the need of a backer.

 

[Corwin]

I'm building a workbench and would dearly love to be about to use Clamping Elements on it.  What size (and BRAND) bits are people using to drill holes that the Clamping Elements will fit in?

I have tried:

Rockler 20 mm bit (too big - the clamp lifts way up when it's clamped)

MLCS 20 mm bit (better than the Rockler - but clamp and workpiece still lifts up 1/16 or so)

McMaster-Carr 25/32 bit (On Order - fingers crossed)

FYI - I have a couple Black & Decker Workmates - and the Clamping Elements fit in those pretty well (results were about like the MLCS bit).   Because one of my workmates is an original (1960's - pre-metric-system) I figured 25/32 was worth a shot.

TIA -

I drilled some holes with that Rockler 20mm bit today and although the holes are over 20mm, they are the same size as the holes in my two newer MFTs -- size comes out about .790".

 

[bdormer]

The 25/32 bit makes a nice tight fit - maybe too tight.  But the clamps DO NOT lift up at all.  The downside is that the 25/32 bit needs a 1/2 drill and some kind of jig (or preferably a  drill press) to drive it.

I have a Festool 20mm bit and a 1/2 adapter collet on order.  My plunge router and I can't wait.

 

[bdormer]

I hate to challenge common wisdom, but my Festool 491072 20mm bit arrived last evening.  I was in a hurry to see how it would work, so I chucked it up in my drillpress (rather than mess around setting up my plunge router) and made  two holes.  I can report this morning that those holes DO NOT fit the Clamping Elements any better than the Rockler or MLCS bits - and in fact, might be the holes with the most slop of all. 

The 25/32 bit I got from McMaster-Carr is going to be my choice for drilling dog holes in my workbench.  The 25/32 holes give a tight fit on the Clamping Elements and there's no lift-up when you ratchet down the clamp.

The Festool 491072 20mm bit was purchased from Bob Marino - he was great - this isn't his fault.  For some reason - either 20mm ain't what it used to be, or Festool has made changes in the Clamping Elements (lucky me, I got the *improved* version).

Given this disappointing performance - I have a 491072 in original packaging that's been used to drill exactly 2 holes in a piece of pine.  It's up for sale - anybody that wants it can have it for $55 (Paypal) - I'll ship USPS priority mail (2-3 days) anywhere in the US.  PM me if you'd like to buy this bit.

bd

 

[nickao]

bdormer put that in the classified section you will sell it sooner.

nickao

 

[ampcabguy]

I'm not sure that you could expect the same performance from a drillpress then from what you would get if you used a good router like the OF1400.
The two things I would be worried about with using a 20mm bit in a drillpress would be the speed for proper chip removal and vibration that could cause the bit to cut a wider hole.

Just a suggestion.

Mike

 

[bdormer]

Mike -

I agree completely - so I performed the test as you suggest.

Using the 20mm bit in a plunge router (a Dewalt DW621) - I get BETTER holes than either of the cheap drillbits (the MLCS or the Rockler) - but the holes are STILL a little loose on the Clamping Elements.  With a 25/36 hole - you have to twist the clamping elements in (like twisting a cork out of a wine bottle, in reverse).  There is NO lift up - even with the Clamps almost maxed out on the Clamping arm.    The Festool 20mm bit is CLOSE to what I want - but not quite.

I can think of two possiblities:  1. The Clamping Elements are a little undersized for a 20mm hole - possibly due to Festool making a design change (like what they did to the MFT).  2. My router has just enough run-out on the shaft that I'm boring an ever-so-slightly larger than 20mm hole.  I'm inclined - given the common wisdom - to concede the latter.

So my choices are - drill 25/32 holes (I've already got the bit) or buy a Festool Router ($330-$800).  Hmmmm.... 

*IF* money was no object - I'd buy the router (heck - I'd buy an ALL FESTOOL workshop If I had about 5 grand just sitting around).  But I live in the real world - where money *IS* an object.  Until I burn up my Dewalt router - I'm stuck with it.

The no-brainer is to drill the 25/32 holes.  And unless something better falls in my lap (I'm done experimenting on this issue) - that's what I'm going to do.

 

[Les]

I use a 25/32 adjustable reamer by hand to size holes. Check Enco 334-1112. Price is

 

[nickao]

Les what do  you mean by hand, literally by hand or with your drill?

Do you use it on existing holes that are tight?

Do you drill a smaller hole then Ream them out? Or do you use the reamer from start to finish?

Nickao

 

[Les]

Les what do  you mean by hand, literally by hand or with your drill?

Do you use it on existing holes that are tight?

Do you drill a smaller hole then Ream them out? Or do you use the reamer from start to finish?

Nickao

Nickao,

I used it by hand to get the holes which are already in the MFT to the same size. The MDF will cut very easy. I use a tap handle and a guide block to keep it square the top. I have 2 MFT's and the newer one has holes .002-.003 smaller. That may have happened when I put poly on the top to keep from ruining it if a liquid is spilled on it. Per suggested using Bullseye Sealcoat, which I did on the first one, after he ruined a top when I believe it was his cat who knocked over a drink. Was out of sealcoat was why I used poly on second table.

I have several locating pins which fit the holes with no slop. I've used them for some time much like Qwas has suggested.

 

[nickao]

The holes on my tops vary also and I never sealed the tops. So it is either the humidity, lack of or a machining difference at the factory. 

I do have some really tight holes in a few of the tops and I may use the reamer to fix them.

Thanks,

Nickao

 

[L2theP]

*IF* money was no object - I'd buy the router (heck - I'd buy an ALL FESTOOL workshop If I had about 5 grand just sitting around).  But I live in the real world - where money *IS* an object.  Until I burn up my Dewalt router - I'm stuck with it.

The no-brainer is to drill the 25/32 holes.   And unless something better falls in my lap (I'm done experimenting on this issue) - that's what I'm going to do.

completely off topic, i'm in the same boat as you, i put a little bit aside every chance i get to get my FESTOOLs, but the unfortunate thing is that 5 grand will barely get you a line of their tools without a single accessory.