Monday, May 17, 2010

Calibrate your MFT fence scale with a Qwas dog

Qwas dogs rock.  Some of my other blog postings show uses for calibrating the position and square of the main MFT fence.  Qwas himself (some call him Steve) has some YouTube videos to show them being used for squared cuts in the field of the MFT, etc.

Awhile ago, I ordered a Starrett adhesive tape (metric/imperial) from Lee-Valley and put it on my MFT fence.  Naturally, this needs to be easily calibrated to the cut line. What I did is this:

Put a Qwas dog in a hole 100-150mm away from the cut line (you want something reasonably long to register against).
Put a stick of MDF against the dog; cut with the already squared guide rail.

Measure it; since I use a metric/imperial tape on the fence, I measured it in millimeters since I could easily eyeball down to a third of a millimeter.  Write it down on the block.

Now that the alignment block is ready, calibrating the fence is trivial: drop the flag stop and put it on the measurement of the block (142mm in my case), push the MDF against the dog and the fence... slide the fence over until the flag stop abuts the MDF.  Now go build a walnut keeper box with handcut dovetails to store this precious alignment tool.

8 comments:

  • Vinyl Virgin said...
     

    How far off the cut line does the right side of your fence reside? Enough for a 45 degree bevel cut? I assume you cut the first few mm's off your adhesive rule? Sorry for the noob questions but I'm just that. Thanks for all of your videos. They have been quite helpful.

  • Paul-Marcel said...
     

    Hi, Vinyl,
    The right edge of the fence is arbitrary when you do this setup. What I mean is if you want it 1/2" or even 3/4" back from the cutline, position the adhesive tape measure so that mark is on the right edge, snip it off, and make the alignment block for it.

    For me, I don't have enough room there for a 45º bevel cut. If I wanted to do that, I'd simply scoot the fence over far enough; I'd lose the ability to set the length of the cut off the measuring tape but it wouldn't be accurate anyway due to the bevel. For example, if your fence was set back far enough for making the bevel cut, dropping the flag stop at, say, 300mm would give you a 300mm long cut only if you are cutting at 90º. The bevel will cut the top of your stock back a little bit, maybe 1-2mm.

    That said, to me losing the tape ability during a bevel cut is a benefit. When I have to move the fence to make room for the bevel cut, I know the tape is off so I'll use other ways to set the distance (you know, pencil marks). Otherwise, I know I'd forget and think the tape was accurate :-/

    I noticed that this posting doesn't link to the video I did about the MFT. You may like that series. Here's the link to the Festool MFT System Review. It goes through all the calibrations visually, which may be nicer. Admittedly, my lighting, camera, and editing work are better now, but it's still helpful :-)

  • greenthumb said...
     

    Paul,

    I have a MFT/3 table. I tried to interpret the fog post on setting this up. Still confused. Will I need to buy another fence rail clamp for this table?

    If there are any hints on how to set up the MFT/3 I would appreciate it . The post was confusing for me.

  • Paul-Marcel St-Onge said...
     

    Hi, Greenthumb... well, I don't have an MFT/3 and only briefly used one as a horizontal surface at a Woodcraft so my knowledge of the table is pretty limited.

    My bet is that you need another rail clamp; there should be one with your table to anchor the left side of the fence with the miter head unit anchoring the part nearest the guide rail. The second clamp takes the place of the miter head so you can scoot the fence all the way to the back.

    You might consider sending 'Sparkitrician' (spelling?) on FOG a private message. Or just post a reply to his posting with the MFT/3 details. Actually a reply to that thread may be a better bet since others who have made the modification could chime in with help. I know in the past he's been very helpful to people setting up an MFT/3 version of this setup.

    At one time, a friend of mine was getting an MFT/3. If that happens, I think I'll visit his place with a camera to roll a video on how to do it after I figure it out myself.

  • Rob said...
     

    What did you use to cut the Starrett scale/tape? I am having trouble getting a clean cut.

    Otherwise, it works great. Thanks!

  • Paul-Marcel St-Onge said...
     

    Hi Rob,

    If I remember correctly, I used a beater chisel.

  • Rob said...
     

    Ah, I'll give that a try. Thanks!

  • greenthumb said...
     

    Marcel

    I dont get how much of the beginning of the Starlrtt tape to cut off and how it relates to this calibration system. It looks like you cut off less than 10 mm. How dud you determine this and how did you adjust this calibration system to account for the cut off so the criss cut would be accurate to yiur needs

    Thanks

    Jim (Greenthumb)