Parallel guides accuracy ?

[NuggyBuggy]

I bought the parallel guides set and tried using it today.  I adjusted both parts of the set as per Brice Burrell's guide (thanks !) - no way I could have done it with the "instructions" that Festool delivers.

Anyways, after adjustment I tried to rip some 10mm strips.  I did this several times and the strips came out between 7 and 9mm wide.  But when I measure the distance from the side of the blade to the the stop, it was pretty close to 10mm (as close as I could get by eye).  I am measuring the distance on the "keeper" side of the blade (when using the extensions).

What kind of accuracy should one expect when ripping strips to some arbitrary width  different from the setup width ? I've seen claims of accuracy to .1mm,  which to me is astounding because I sure don't think I could sight the scales to +/- .1mm in the first place.  If I'd measured the distance from blade out to stop before the cut of arbitrary width, maybe I'd understand it.

Is there some obvious mistake that newbies might make when using the guides, esp. the extensions ?

 

[peter halle]

Nuggy,

Someone will chime in with help.   I used them in class, then bought them.  I haven't used them yet.  I assume you also bought the guide extensions that you can use to the right of the blade.

 

[nickao]

How can you keep something like that and not use it! Usually when I get a new tool I go directly into the shop and run it through the paces. 

 

[peter halle]

Nick,

When I got my TS-55 - my first festool - i didn't use for a couple of months.  I did touch and feel.

Your use of tools is different than mine - and I had the opportunity to attend training.  I saw what it would do - incredible in my book - and then I saw Brice bring it up a notch.  I don't do the same thing everyday, and I am actually using my other Festools to do unrecomended other tasks.

They will be there when I need them!

 

[WarnerConstCo.]

How can you keep something like that and not use it! Usually when I get a new tool I go directly into the shop and run it through the paces.   

I usually find 3 or 4 unused tools when I clean the garage.

Sometimes I just need that warm fuzzy feeling a new tool gives you.

 

[nickao]

The anticipation of waiting to try the tool out would kill me!

 

[NuggyBuggy]

Nuggy,

Someone will chime in with help.   I used them in class, then bought them.  I haven't used them yet.  I assume you also bought the guide extensions that you can use to the right of the blade.

Thanks Peter, I hope so.  My first attempts were indeed with the extensions, as I mostly bought it to make narrow cuts.

I also had my set lying around for a while unused.  I bought it when Festool had their sale on rails and accessories a while back, and only just took them out of the box.  It was one of those buys where I didn't need it right away, but I knew that I would need it eventually and when I did, I'd be kicking myself for not saving that 10% and having it readily at hand.

 

[tbellemare]

I bought the parallel guides set and tried using it today.  I adjusted both parts of the set as per Brice Burrell's guide (thanks !) - no way I could have done it with the "instructions" that Festool delivers.

Anyways, after adjustment I tried to rip some 10mm strips.  I did this several times and the strips came out between 7 and 9mm wide.  But when I measure the distance from the side of the blade to the the stop, it was pretty close to 10mm (as close as I could get by eye).  I am measuring the distance on the "keeper" side of the blade (when using the extensions).

What kind of accuracy should one expect when ripping strips to some arbitrary width  different from the setup width ? I've seen claims of accuracy to .1mm,  which to me is astounding because I sure don't think I could sight the scales to +/- .1mm in the first place.  If I'd measured the distance from blade out to stop before the cut of arbitrary width, maybe I'd understand it.

Is there some obvious mistake that newbies might make when using the guides, esp. the extensions ?

I don't see how you could be off by 2-3mm using the Parallel Guides.

You talk about measuring the distance on the keeper side. If you are making thin strips using the Extensions, the stops should be on the extensions. You also have to calibrate them by moving  the stops to zero and adjusting the Extensions so the stops then abut the blade, which it seems you did.

After proper calibration, it is easy to get each Extension within .5mm of one another - they are graduated in 1mm increments.

If you require more precision, you can make a gauge block.

Tom

 

[nickao]

Are the results exactly repeatable? If they are no big deal.

 

[Wonderwino]

I calibrated long sides of mine with a 200mm gauge block that I cut on my SCMS and the short ones by zeroing on a marked tooth on the blade.  Brice also recommends setting the second stop on the parallel guides by sliding them together and setting it by feel.  I used this method when calibrating the long guides also; I set one side with the gauge block, slid the other side up to the first, loosened the set screws and proceeded to set the calibration on the second guide.

The pointers on the stops can be easy to mis-set.  I have a solution with the improvement I designed an hope to have an improved version in production soon. http://festoolownersgroup.com/festool-tools-accessories/parallel-guide-improvements/

You might also check the gibs on your saw.  When making parts as small as yours, a slight amount of slack will show up in a hurry.  Be sure both gibs are fully engaged for the entire cut.  You may need a longer rail if they are not.

 

[joiner1970]

I too have a parallel set waiting to be used and I'm a pro not a hobbyist I bought mine 2 or 3 months ago now and still haven't even set them up yet. Its just the way it goes very busy working but none of my work at the moment involves cutting up lots of MDF, sheet goods.

 

[Kevin D.]

I recently used mine for the first time as well.  Not even sure they were calibrated, but they nevertheless did the job I needed them to do.

In the consolidated list, there's been a slew of broken links pointing to the UK site for tutorials due to the UK site revamping their website a few months back.  Jerry Work also has a useful tutorial on the guides, for which the link is bad, which for those looking for can be also found here:

http://www.mcfeelys.com/docs/IS/495717.pdf

Thank goodness for guys like Brice and Jerry doing these things.  As someone previously mentioned, can't seem to get Festool to put more comprehensive instruction manuals together, which is one of the few major Festool shortcomings imo.

 

[NuggyBuggy]

Anyways, after adjustment I tried to rip some 10mm strips.  I did this several times and the strips came out between 7 and 9mm wide.  But when I measure the distance from the side of the blade to the the stop, it was pretty close to 10mm (as close as I could get by eye).  I am measuring the distance on the "keeper" side of the blade (when using the extensions).

I don't see how you could be off by 2-3mm using the Parallel Guides.

You talk about measuring the distance on the keeper side. If you are making thin strips using the Extensions, the stops should be on the extensions. You also have to calibrate them by moving  the stops to zero and adjusting the Extensions so the stops then abut the blade, which it seems you did.

After proper calibration, it is easy to get each Extension within .5mm of one another - they are graduated in 1mm increments.

If you require more precision, you can make a gauge block.

Tom, right now, I'd be happy to get within the .1mm that others have reported to get within - even .5mm for now.

My stops are indeed on the extensions.  On the extension side, I had been calibrating by setting the stops to some distance like 150mm, then measuring the distance to the blade.  This I got from Brice's tutorial.  I started wondering whether my rule was off, and if so, your method of zeroing the stops and then moving the extension so stops abut blade would avoid this.

I just tried it and I had the same problem, which makes absolutely no sense to me.  Zeroing and then adjusting should work almost by definition, although I'd think calibrating with stops at a larger distance would be a bit more accurate.

Unrelated question: how is one supposed to keep the piece up against the (cutting) guide rail ? The only thing I can think of is having another piece of wood exactly the same width sitting under my piece, but that would be tedious.

 

[NuggyBuggy]

You might also check the gibs on your saw.  When making parts as small as yours, a slight amount of slack will show up in a hurry.  Be sure both gibs are fully engaged for the entire cut.  You may need a longer rail if they are not.

WW, I'm not even sure what the above means or where the "gibs" are  [embarassed].  Any additional info would be greatly appreciated.  You can take it offline by PM if you think that'd be better.

 

[tbellemare]

Whenever you use a Festool product on the Guide Rails, you have to take the slop out where the tool rides against the "hat" on the Guide Rail. The TS saws have two green gibs that are used to take the slop out of that system. You adjust them until there is no lateral movement but it still slides.

Tom

EDIT: I doubt that you are getting multiple mm's worth of misalignment from the gibs.

 

[fshanno]

The key is repeatability.  If the error in the stop is dead on repeatable then you've got no worry.  You just have to know how far off you are and compensate.  Make a test rip and measure.  Then set the stop compensating for how far off you are.  If you want 10 and set it for 10 but get 9 then set the stop at 11 and see what happens.   I bet you get 10.

Every time I set up I make the first rip 5mm wider than I need and see how far off I am.  I'm always off at least a little.  Interestingly the amount of deviation can vary from session to session.  Maybe it's temperature, I don't know.  And it varies, sometimes I'm long sometimes I'm short.  I use the deviation as an adder and great good accuracy for the rest of the session.

If I intend to make a good number of rips I stick a piece of blue tape on each arm and note the compensation number on each arm and the extensions if I'm using them.

I calibrated the things a few times when I first got them and then I just gave up on that.  With the compensation method and I get good rips, better than .5mm accuracy for sure.  It's a little bit of extra math but it works.

 

[NuggyBuggy]

fshanno,

If your experience is the norm then I have to say I'd be a little disappointed. How would one know when or how often you'd have to recalibrate ? Maybe between sessions is enough, but it sounds like some variation could be occurring during a session as well.  Is the variability you experience in a given session  a constant amount (i.e. +1mm), or is it a proportion (say, +1mm every 20 cm) ?

At any rate, if variability of either type  is to be expected, I'd be rueing the fact that I didn't test it out before my 30-d return policy expired.

I don't think people would be happy if, say, their table saw fence varied between days.  Anyways, I'm not prepared to give up on mine yet.

 

[RDMuller]

Take a look at these 3 videos that I developed on cutting sheet goods with Festool, the parallel guides, and the parallel guide extensions.  You should have no problems working within the precision range you desire.  Incidentally the first video just won the Best Training Video in a national contest sponsored by Cabinetmaker magazine published in the August 2010 issue. 

http://festoolownersgroup.com/festool-tools-accessories/parallel-guides-and-extensions-3-videos-on-usage-and-cutting-sheet-goods/

 

[JeromeM]

What kind of accuracy should one expect when ripping strips to some arbitrary width  different from the setup width ? I've seen claims of accuracy to .1mm,  which to me is astounding because I sure don't think I could sight the scales to +/- .1mm in the first place.  If I'd measured the distance from blade out to stop before the cut of arbitrary width, maybe I'd understand it.

Your accuracy should be as good as the way you set it up. ie if using the built in ruler with no mod then within 2mm with mods within .5mm. If using a setup up block then .1mm would be realy good

Is there some obvious mistake that newbies might make when using the guides, esp. the extensions ?

Yes. having the guides too tight to the work on the sides and not butting the stops tight to the work. Also letting the guides fall down at the end away from the work.

My mods are in this thread http://festoolownersgroup.com/festool-how-to/key-additions-to-the-festool-fs-pa-and-fs-pa-vl/msg97615/#msg97615

 

[NuggyBuggy]

@rdmuller - thanks for the videos.  They were indeed very well done.  I especially liked your addressing of one of my issues, i.e. dealing with thinner material that leaves a gap to the rail. 

@jeromem, why would having the sides tight to the piece be a problem ? Also, as far as I could tell, none of the mods that you did would seem to increase the accuracy, am I wrong ?

thanks everyone, I'm optimistic I'll be able to work this out with the kindness of the group.