UJK Parf Guide MKII - What kind of tolerances in the hardware?

[4nthony]

I received a UJK Parf Guide MK II from Axminster Tools yesterday and one of the first things I noticed is some slop in the drill guides.

For those of you with the MK II system, how snug do your drill guides fit into your rulers? Are they looser than your pins? My pins are right on the cusp of 5.95/5.96 and the drill guides are at 5.94.

In this clip, the double length drill guide is seated into both rulers at the top of the triangle (see bottom photo):





I have the UJK Track Saw Set and my goal is for the outfeed table to have roughly 8 dog holes (2 for guide rails, 6 for a fence) on a right angle to make crosscuts on large material. I'm not planning on having a full grid.

Testing with a straight edge resulted in:



This is where the play in the first video is happening using the deeper drill guide. I've seen videos where this corner get clamped but I'm wondering if there should be any play? The pins themselves are nice and snug but the drill guides, not so much.

If this play is common, then most likely my technique resulted in the failed straight edge test. But the amount of play in the drill guide kinda -- read, unscientifically -- feels like the same amount in the straight edge.

I had some preexisting dog holes on the table that were done with an Origin (and which are also slightly out of square) so I used the Parf Guide between the existing holes. For the most part, the rulers all lined up and the pins fit without any issue.

The only real problem seems to be the play in the drill guides when inserted into the rulers.

The "Revision guides" I received to pair with the protractor also introduce quite a bit of slop but I'll save that part of it for later.

Does my hardware seem sloppy to you guys? I have not made any cuts yet so this may all be moot once the saw hits the wood -- it is woodworking after all and not rocket building -- but my OCD is OCD'ing and I keep hearing Peter Parfitt in the back of my head saying, "absolutely perfect"

 

[smorgasbord]

My pins are right on the cusp of 5.95/5.96 and the drill guides are at 5.94.

This gets very engineering detailed very fast.
There's a thing call "ISO Tolerances" that one can use to machine holes and pins.
For this kind of application, where pins need to be removed and replaced in holes, one normally tries for a "clearance fit," but in this case they're probably trying to something closer, but not to the point of an interference fit.

For a 6mm hole, a 0.01mm - 0.02mm gap seems about right, and shows pretty darn good manufacturing tolerances.

For instance, your Vertias straight edge is guaranteed to be within 0.003" over its entire length. That's 0.076mm, which is quite a bit larger than your pin/hole clearance. So, for holes drilled far enough apart, the 0.02mm gap is not in itself a problem (although how straight the guide is and how accurately the holes are placed are additional factors0>

I'm wrestling with similar issues in my angle cross-cut sled. Right now I'm getting away with an interference fit since I'm putting SS pins into MDF holes, but that will wear over time with usage, leading to increased errors. One potential solution I'm examining is use of tapered pins in tapered holes. That would at least reduce play so even if results are just slightly off, at least cuts will be consistent.

 

[smorgasbord]

Watching this video now:


At 8:35 in there's an example that's somewhat relevant.

Of course, this doesn't address what UJK/Peter Parfitt intended.

 

[4nthony]

Interesting video. I'll have to watch it a couple more times to fully grasp the concepts.

I'll reach out to Axminster and ask if there should be play in the rulers when using the double-length drill guide to make a connection. On some tables, you'd be off the table and would use the threaded dowel to lock the pins, but in my case, I'm still on the table and need the drill guide. Because of this small amount of play, it's like I'm already set up to be out of square. It's not "rock solid" as mentioned in the video.

 

[bertv]

One hundredth of a mm 'slop' when drilling the holes? Considering that Festool's margin of error for the MFT/3 and their OG dogs is around five hundredths of a mm that is absolutely acceptable.

 

[4nthony]

One hundredth of a mm 'slop' when drilling the holes? Considering that Festool's margin of error for the MFT/3 and their OG dogs is around five hundredths of a mm that is absolutely acceptable.

Right? I get better cuts with my rail square. It’s just more work to make the cuts repeatable.

So you don’t think that play in the hardware is going compound depending on how far the holes are placed? I want to achieve repeatable crosscuts on large panels for making pantries, built-ins, etc. That connection point sets up the first 90°.

Perhaps I’ve fallen victim to perfection marketing. Do you use the Parf system?

 

[smorgasbord]

I thought the idea is to construct a large right triangle and then drill holes along the sides, not extending beyond the vertices.
Thus, any error inside would be smaller. One of your videos appears to show extending beyond the vertices.

 

[4nthony]

I thought the idea is to construct a large right triangle and then drill holes along the sides, not extending beyond the vertices.
Thus, any error inside would be smaller. One of your videos appears to show extending beyond the vertices.

Hopefully this helps explain what I'm experiencing:

In my video with the movement, I had already drilled the holes (row 1 and row 2). I used existing holes in order to put the triangle back together and show the movement over a hole.

I was hoping to hear from others with the MK II system about whether or not they have movement at the connection when using the drill guides. For reference, when I put a pin into the hole, the rules do not have any play.

 

[smorgasbord]

I labeled two holes.
If "A" is the one with play, then "B" will be off less than half the amount of play.

 

[4nthony]

I labeled two holes.
If "A" is the one with play, then "B" will be off less than half the amount of play.

So probably within tolerances, at least tolerances "good enough" for woodworking

 

[Mike Goetzke]

Anthony - I just checked mine and the pins are snap-in tight in the holes. I can not feel any play. I purchased the MKII when it just came out. I had many issues with the rule quality. Back then Axminster was very proactive to take care of me. The last set, which I think is good, used a different process to make the holes. As I recall I had to remove burrs around the holes because they were so bad the pins and hold downs wouldn't sit flat on the rules.

I never used this tool because I needed holes in a 4'x8' sheet of MDF and while messing with the rules I found a local sign shop with a CNC that was able to use my simple CAD drawing to make the top at a reasonable price.

If you need me to measure something let me know.

(Just found the old thread on this. May interest you or bore you to death: https://festoolownersgroup.com/threads/parf-guide-mark-2-issues-and-questions.58028/page-7 )

 

[4nthony]

Anthony - I just checked mine and the pins are snap-in tight in the holes. I can not feel any play. I purchased the MKII when it just came out. I had many issues with the rule quality. Back then Axminster was very proactive to take care of me. The last set, which I think is good, used a different process to make the holes. As I recall I had to remove burrs around the holes because they were so bad the pins and hold downs wouldn't sit flat on the rules.

Just to be clear, when you say "the pins are snap-in tight" which are you referring to, the 3 pins for holding down the ruler or the drill guide with the longer nipple?

If you can mount the rulers and use the drill guide with the longer nipple to connect them, that would be the connection I'm interested in learning if there is play.

Thanks!!