TSO parallel guide system inaccurate metric scale?

[serge0n]

I just recently became a happy owner of the TPG parallel guide system by TSO. The system is very well made and thought out, I think it's the best parallel guide solution out there.

However, my 30" tracks have an issue - the metric scale is approximately 1 mm off.

I calibrated both flipstops by following the manufacturer's instructions: set both stops at the 10" mark, then set my Woodpeckers adjustable square to 10 inches, firmly pressed it against the guide rail and secured the calibration rods against the end of the square.

Then I made a mark on my work piece at 545 mm using Fastcap's True32 tape measure and set the TGP guide at 545 mm. My mark was almost exactly 1 mm away from the guide rail.
I then used the same Woodpeckers square that I did not readjust and made a mark at 10 inches. Set the TGP guide to 10 inches and voila! It was spot on, precisely on my mark.

Did anyone else who owns this system noticed anything similar? Are metric and imperial scales a little off and I have to calibrate for the metric scale separately?

 

[Dr. P. Venkman]

I’ve only ever used the metric scale on mine, so I’ve just calibrated to that. But looking at the track, the metric and imperial scales appear to line up like they should (10” in line with 254mm).

It could be your tape measure. Since 10” on your Woodpecker’s square and the TSO guide agree, did you check that against 254mm on your fastcap tape?

 

[tjskinny]

I have the TSO parallel guides and had a similar issue which caused me to start double checking any new measuring tool to a known good measure.

I used adjustable square I trust to calibrate the TSO gude rails per the setup instructions to the 10 inches.

I prepared my material to cut, set the TSO guide rail to a measurement in mm, don’t recall the exact dimension, made a mark on the material at the edge of my track.  Measured to my mark with my Fastcap PMS-16 tape measure, which is metric / imperial scale and it was 1 mm off which I thought was strange. 

I double checked the calibration on the TSO guide again, it was dead on.  I then checked the mark with my Woodpecker scale, it was the dimension I set on the TSO guide. I compared the Fastcap PMS-16 tape measure with the woodpecker scale and there was a 1mm difference.  So I then grabbed my Parf Guide scale and compared that to the Woodpecker scale and the Fastcap PMS-16.  The Parf guide matched the Woodpecker scale and the TSO scale. The Fastcap PMS-16 tape measure was off.

Made my cut and it was what I had set the TSO guide to.

Lesson learned for me.

 

[thudchkr]

I’ve also found the Fastcap tape measures to be off when compared to Starrett rules and to my Lee Valley rules.

FWIW, I’ve also found my woodpecker “aluminum” rules to vary from those other at times depending on the temperature. A bit more variance seems to occur depending on what temperature the rules are at. Haven’t had any issues with my SS woodpecker rules, any of my Starrett items, or for that matter, any other of my quality steel rules.

Needless to say, I don’t rely on my Fastcap tapes if a precise measurement is needed.

Having said that, I just checked my True 32 tape against a 1 meter Lee Valley rule and it was only off by about a quarter of a millimeter, so that particular tape is “relatively” accurate.

 

[serge0n]

[member=8008]tjskinny[/member] and [member=2575]thudchkr[/member] - thank you! Such an eye opener. I was sure the Fastcap tape was pretty accurate, looks like that may not be the case.
I will check it against a good American made steel rule and report back.

I did another check yesterday by making a mark at precisely 500 mm with the Fastcap tape. It was about 0.7 mm out on the TSO guide scale, not as bad as 1 mm, but still frustrating.

I made a test cut at the 10" mark with TSO guide and it was dead on, exactly 10" according to my Woodpeckers stainless steel square.

[member=2575]thudchkr[/member], you had an interesting observation regarding the temperature change. How big was the temp swing?

Does anyone have a recommendation on a metric tape that is more accurate than Fastcap's True 32?

 

[MikeGE]

Does anyone have a recommendation on a metric tape that is more accurate than Fastcap's True 32?

Any of the Hultafors metric Class 1 products:
https://www.hultafors.com/products/tape_measures/H0038-short-tape-steel-bt/79367

 

[rst]

Hultafors  [thumbs up]

 

[Mini Me]

I never use a construction style tape for anything connected to woodwork unless it is made to a European standard, Hultafors and BMI are two that meet this standard. The one I mostly use in the workshop is one of these

The two metre length is metric and the three metre version is a combination metric/imperial scale. It fits in the pocket and is a very handy thing to use.

 

[Michael Kellough]

I bo one each of all the FastCap tapes a decade ago and ended up throwing all of them away except the story pole version and the flat tape style. The crappy tongue made the others useless.

 

[jarbroen]

Where do you gentlemen in the US purchase Hultafors tape measures?
I haven’t had any luck finding a US dealer that sell their tapes.
I don’t mind ordering from another country, but the couple sites I looked at don’t ship to the US.

 

[Cheese]

Over the last couple of years there have been several threads on shop tapes and their accuracy or lack thereof.

A few years back I trashed all of my tape measures after I had some issues with the tape in the garage vs the tape on the Kapex vs the tape on the bench vs the tape I carry on my person. I purchased new Starretts in imperial & metric.

 

[guybo]

"[member=65755]jarbroen[/member]"[attachimg=1] great tapes guy

 

[Packard]

I never thought about the accuracy of tape measures until just now. 

I see from this site that there are "class I" and "class II" tape measures. 
https://www.thetapestore.co.uk/tapes-rules/tape-measures/tape-accuracy

If you thought that all tape measures were equal you'd be wrong... one tape measure is not necessarily as accurate as another. Whilst your average 'bargain basement' tape will be unclassified (i.e. its accuracy cannot be traced to any known standard), most professional tapes are Class 2. Others are Class 1 - the highest level of accuracy available. Whilst Class 2 tapes are ideal for the majority of users, some professions require that little bit extra... for them only a Class 1 tape will do.

I see that Amazon sells class 1 and non-class rated only.  I could not find any Class 2 rated listed there.
https://www.amazon.com/Master-Precision-Class-Tape-Width/dp/B00G7K5XS6

Class 1, 16 foot, $41.00.

I am not seeing any Class 2 tape measures.  Lufkin and Starrett are not showing any class rating and it is probably not produced to any known standard.

Addendum:  I did finally find a Fuso Class 2 tape on Amazon.com

$17.00 for an 8.5 foot model.https://www.amazon.com/FUSO-FUSOTM51625-Class-Steel-Measuring/dp/B07C47ZSF7

Addendum #2.  Though Lufkin's listings are not rated on Amazon.com, they claim that all of their tape measures are class 2 rated with some exceptions.  But Amazon does not seem to list those classifications so I am still not clear on the Lufkin tapes.
http://www.pewa.de/DATENBLATT/DBL_CT_BANDMASSERSATZ_DBL_DEUTSCH.pdf

85(a + b x L)EC-StandardizationEach Lufkin measure tape (steel) corresponds to the Class II of the European Weights and Measure Regulations (except CMEtapes and HY-series). Tolerance of dimensional accuracy in mm ± is for the whole tape length.

Addendum #3.  Went to Starrett site.  They list "exact" and "exact plus" tapes.  But in the specifications they do not list any rating for the tapes.  So I am uncertain what standard they trace back to.
https://www.starrett.com/metrology/product-detail/KTXP106-5M-N#Downloads

 

[squall_line]

If you want an inordinately deep dive:
https://www.popularwoodworking.com/cnc/precision-instruments-woodworkers-part-two-rules-tapes/

I still have that bookmarked from the first time I read it.

 

[Packard]

From a practical point of view for my projects (mostly cabinets and cabinets masquerading as furniture) absolute accuracy is not essential.  What is essential is repeatability.

If I was to make a suite of 40" tall upper cabinets, then all the 40" cut boards have to be exactly the same length or else the row of cabinets would look like a ragged end of worn-out jeans. 

And the three panels on each cabinet would have to be identical or it the ends on the cabinet would not align. 

I do have a 48" and a 60" straight ruler that I use, and an oversize Woodpeckers T-square (I forget if it is 32 or 36" long). 

I used to cut the side panels on my radial arm saw with a positive stop, after pre-sizing it with the Festool saw.  But I discovered that I can get sufficient accuracy using Festool track saws to skip the pre-sizing step and cut directly to the finished sizes. 

That said, I might get that $40.00 tape measure.  I will have to think about that.

I don't rely on my vision for repeatable results.  I use a couple of stair stops (usually used on a carpenters' square) as a positive stop for measuring using the 48" or 60" ruler.  Basically, I measure once and then transfer that measurement using the ruler and stops.  It works very well.  And cheap too.

 

[ChuckM]

All tapes in my shop are excellent tapes for measuring purposes -- as long as I stick to the same tape throughout a project.

I've never thrown away a tape...I have about 9 to 10 tapes scattered around the shop, all different brands except four of them, which last time I checked were also slightly different among them. More or less, that observation is also true for my steel rules (over a dozen of them of various brands, made in Canada, the US, Japan, etc.).

I also know that pretty much none of the 9 or 10 tapes in my shop is the same as the scale on my SawStop, or the scale on my Jesseem miter gauge. In my furniture making, it doesn't matter how accurate a tape or a rule is per se compared to the highest standard, as long as the measurements are consistent (i.e., by using the same tape).

 

[serge0n]

From a practical point of view for my projects (mostly cabinets and cabinets masquerading as furniture) absolute accuracy is not essential.  What is essential is repeatability.

I fully agree. However to achieve repeatability all of your measuring tools have to have exactly the same scale. Using the same tape measure for all measurements on a project is doable, but is also a huge pain. Case in point is my first post in this topic - I can't use the crappy Fastcap tape measure and TSO parallel guides on the same project or parts cut using different scales won't match.

On my projects I typically use a tape measure (Fastcap True 32 was my go to, not anymore), PEC steel rules, Festool and Wiha folding rules, a iGaging calipers (which are pretty accurate) and Woodpeckers squares and rules. I don't trust machine scales (except the one on my Inca planer/jointer, that scale is accurate to 0.1 mm) and always check settings with a rule or a tape measure.
I'm not going to cripple my workflow by limiting myself to just a single tape measure for all measurements, so all of the tools I use need to be exactly the same.

I will recheck all of my measuring tools using a PEC steel rule and Woodpeckers SS combination square blade as references. Both PEC and Woodpeckers have exactly the same scales and are supposed to be very accurate tools.

As I learned from this thread, aluminum rules and squares are more easily impacted by temperature changes, I'm going to make a mental note to purchase stainless steel versions of Woodpeckers whenever I need a new square or rule.

That said, I might get that $40.00 tape measure.  I will have to think about that.

I ordered one yesterday, the one [member=70363]MikeGE[/member] recommended. Hultafors BT8M, looks like a lovely tape. With shipping it was $46 which is outrageous for a tape measure, but on the other hand a tape measure is one of my most frequently used tools. If I can shell out hundreds for an accurate tracksaw that doesn't get out of it's systainer every week I surely can spend $50 on a high quality Class 1 tape.

Hultafors Talmeter is a class 2 tape measure. I bought it as well to see how it stacks up against it's more accurate sibling.

I don't rely on my vision for repeatable results.  I use a couple of stair stops (usually used on a carpenters' square) as a positive stop for measuring using the 48" or 60" ruler.  Basically, I measure once and then transfer that measurement using the ruler and stops.  It works very well.  And cheap too.

That is a brilliant idea! I will try it next time I need to transfer a measurement.

 

[Packard]

A reviewer on Amazon reviews that $40.00 tape:

By far the best tape measure I have ever purchased. It is highly readable which adds to its accuracy and in use it is very smooth and easy to handle. A plus is its accuracy. It is well worth the money. The satisfaction of using a good tool is felt long after the price is forgotten. BTW it is a cabinet/furniture makers tape, I don't know why anyone would buy it for carpentry.

 

[MikeGE]

All tapes in my shop are excellent tapes for measuring purposes -- as long as I stick to the same tape throughout a project.

I've never thrown away a tape...I have about 9 to 10 tapes scattered around the shop, all different brands except four of them, which last time I checked were also slightly different among them. More or less, that observation is also true for my steel rules (over a dozen of them of various brands, made in Canada, the US, Japan, etc.).

I also know that pretty much none of the 9 or 10 tapes in my shop is the same as the scale on my SawStop, or the scale on my Jesseem miter gauge. In my furniture making, it doesn't matter how accurate a tape or a rule is per se compared to the highest standard, as long as the measurements are consistent (i.e., by using the same tape).

I learned the hard, and expensive, way to use one tape.  I agreed to cut some shelves for a friend about 70 KM away.  He measured the distance between the sides and I cut all of the shelves.  After loading them in the truck, driving to his apartment and carrying them up four flights of stairs, the shelves were too short.  I didn't think to bring my tape measure with me, but measured the shelves with his tape and sure enough, the shelves were 4mm to short.  I left the short shelves with him and went home for another attempt with my tail tucked between my legs.

At home, I pulled another sheet of 19mm plywood out and cut another set of shelves.  Another drive to his house, another haul up the stairs, and again the shelves were 4mm too short.  This time, I brought my tape measure and the shelves were correct according to my tape, but too short when measured with his.  Our tape measures were 4mm out at the distance we were measuring, about 120cm, with my tape being shorter.  I don't know which one was correct, but it didn't really matter.

That's when I tossed all of my tape measures in the bin, except for an 8-meter tape I keep in the truck for rough measurements.  I bought the Hultafors Class 1 tape measure and two BMI class 2 folding steel rulers.  I also no longer trust anyone else's measurements unless they have a Class 1 tape measure.

 

[ChuckM]

[scared]

Blunder x 2!