Thin Rip Jig Mk4 to make kumiko strips

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pulleyt

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I’m still looking for my preferred way of preparing the thin Kumiko strips. I’m now of method no. 4 and I’m hopeful that this might be ‘the one’!

I’ve made a table saw jig based on a couple of shorts on YouTube, Matt Kenney – Sled for ripping kumiko strips and A91 Customs – Thin Strip Jig…questions?. I’m not keen on either method of holding the board while it was being cut so for my version I wanted to introduce a mechanical way of holding the board in place as it goes through the blade.

The boards to be cut are dimensioned to 12mm thick and 500mm long. These can be different but that makes a stock kumiko strip that works for me.

The jig comprises two main components. The first is the fixed table which is clamped to the table saw stop. This is a 12mm MRMDF base with a runner that sits in the mitre slot to the right of the saw blade. On the base there is an adjustable stop fence that finishes just before the blade. Then there is a see-through blade guard. (I also added a deflector at the front of the table to guide the cut strips away from the blade when the cut is complete – the jury is out on how effective this is).

ThinRip Mk4 - 01.jpg


The sliding table comprises a base, again made from 12mm MRMDF. This has a fixed mitre fence at the rear of the sled and an adjustable mitre fence at the front. I’ve fixed hold-down clamps on each of the mitre fences.

ThinRip Mk4 - 02.jpg


ThinRip Mk4 - 03.jpg


I trimmed both components by running them through the blade using the mitre slots effectively making the tables zero clearance.
After each strip is cut I return the sliding table to align to the stop fence on the fixed table, reposition and clamp the board, make the next cut and so on.
Once the board’s width is narrower than the hinged clamping plate I place the next board next to te first and carry on cutting strips.

ThinRip Mk4 - 05.jpg


I can carry on cutting the board until there is very little waste.

ThinRip Mk4 - 06.jpg


From the first use I do think this really might be the method I use going forward.

ThinRip Mk4 - 07.jpg


I’m aiming to get strips at 2.35mm ± 0.05mm. I’ve tabulated the thicknesses of the start and end of each strip below.

ThinRip Mk4 - 08.jpg


A couple of the strips will be a tight fit if used in halving joints but I can finesse them if needed. But I’ll probably just use those for elements that don’t include joints.
 
Kumiko is something i have on the round to it list. Nice work with the approach to making the strips!
 
A couple of hours in the shed this afternoon and I've added a little over 130 metres of 12mm x 2.35mm (± 0.05mm :) ) of kumiko strips to the wood store. These were all cut from some gifted t&g boards which I believe are all cedar, albeit with some considerable colour difference. Any way, it is all as soft as cedar which makes it suitable for kumiko work.

ThinRip Mk4 - 09.jpg


130 metres sounds a lot but it soon goes :(
 
How are you cleaning up off saw marks ?
I'm happy to use the strips straight from the saw. There are some faint saw marks...

saw marks 01.jpg


... but you need to look closely to see them.

saw marks 02.jpg


Another reason that I'm happy to accept the finish from the saw is that it is the thin edge that is presented to the eye in a kumiko pattern so you don't get to see the wider side 'head on' if that makes sense.

One of the reasons that I was keen to hold the boards to the sliding table mechanically is that it is probably a more consistent hold than I might do by hand if I used either of the options in the two videos I linked to in the top post - I don't know if this makes a difference.

It has worked fine with the nice soft cedar - if I were to try something like purple heart I presume I'd get more burn marks and I would have to cut slightly thicker and then clean the marks off in the drum sander.
 
Good job. I've been mulling over the best way to cut consistent thin strips (not for kumiko) and I've tried a couple of the methods available to view on Youtube but none of them were particularly convincing. I eneded up using the 'nudge the fence' method which was OK but required more patience than I had available.
Can you explain your table of figures please, I can't get my head around it.
 
I googled this and it seems Kumiko strips are readily available online. Smooth both sides and a consistent thickness..
(for those without machinery and want to give this a go)
 
Can you explain your table of figures please, I can't get my head around it.
I cut 25 strips from the first board and I wanted to check the thickness of each strip. I took a measurement at the end that was the start of the cut and also the back end of the cut. I took both measurements to check that the strip had close to parallel sides. The first column is the thickness reading, the second column counts how many strips measured that thickness at the start of the cut and the third counts the number of strips with the thickness at the end of the cut.

I haven't kept the relation between the two measurement of each strip but thought I'd show the table to show that the measurements for 23 out of 25 strips fall within the margin of error I was hoping for (2.35mm ± 0.05mm).
I eneded up using the 'nudge the fence' method which was OK but required more patience than I had available.
That was my least favourite method! and probably the least consistent.
 
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