Rob Cosman's Dovetail marker

[rob mason]

After watching Rob Cosman's video on his 3 1/2 minute dovetail, I am hooked. One device he used was called a 'dovetail marker' which I suppose has the 1:6 and/or 1:8 angle for marking the sides.

Does anyone have plans on how to make one?

The video was at:
http://blogs.popularwoodworking.com/editorsblog/

Thanks!
Rob

[Robert Rozaieski]

It's really just two pieces of wood glued together in the shape of a "T". The top piece is a square and the bottom piece has the proper angles sawn into each side. I think he sets his bottom piece into a shallow dado in the top piece for a little extra support, though, I'm not sure it would really matter. I believe he sells them on his website as well if you don't want to make one.

FWIW I use a sliding bevel, which works fine. I've never really felt the need for a special marking jig just for dovetails. Using the sliding bevel also lets you set the tail angle to whatever you want and not be fixed at whatever the two angles on the marking jig are. In addition, the downside to these jigs is that they are designed for marking a single piece at a time. If you gang cut your tail boards, the top part of the jig won't be long enough to square across the ends of multiple boards simultaneously, requiring you to use a separate square anyway.

[bob greenshields]

Harris Tools offers a set of markers that are similar in form and function. Looks like the major difference (advantage?) is that they use brass where Rob's use birch or maple to register the mark. The brass might be sturdier if you ever use a knife instead of a pen for marking. I got a pair from Highland Hardware a while back. They're real handy. Can't find them on Highland's site this morning. Here they are at Harris' site: http://www.harristools.com/catalog/product_info.php?cPath=25&products_id=46&osCsid=35f2a365e1497b81895bc6808df0b82a

[Mark Singer]

After watching Rob Cosman's video on his 3 1/2 minute dovetail, I am hooked. One device he used was called a 'dovetail marker' which I suppose has the 1:6 and/or 1:8 angle for marking the sides.

Does anyone have plans on how to make one?

The video was at:
http://blogs.popularwoodworking.com/editorsblog/

Thanks!
Rob
You can easily make a dovetail marker.. He is quick!

see this for the marker...

http://www.wkfinetools.com/contrib/mSinger/z_art/htDovetails/htDove1.asp

[Al Navas]

Rob,

I found the link, but in a different location (http://blog.woodworking-magazine.com/blog/PermaLink,guid,c6fc4517-9fe4-485e-a255-25cffa6d335d.aspx). Pretty amazing video!

If you select the make-your-own route, you may be interested in reading Christopher Schwarz' Dogmatic About Dovetail Angles (http://blog.lostartpress.com/2008/03/19/Dogmatic+About+Dovetail+Angles.aspx). He has pretty much settled on 14° for his dovetails, based on looks.


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[Joe Vincent]

This won't help you with making one if that's what you want to do, but Rob sells them on his website and Lie Nielsen (for whom Rob used to be a representative) sells a version of this style dovetail marker as well.

[rob mason]

Excellent info guys.

I sure would like to make my own as I have found in my research that 14deg seems to be the most pleasing to the eye.

Thanks for the tips - I am really getting stoked about hand cut dovetails! I have tons of scrap cherry and walnut that I need to build something with. I will practice on pine first though until I get comfortable.

Watching the competetion for the 3.5min dovetail between Cosman and Klaus(?) should really inspire some folks!

[rob mason]

It's really just two pieces of wood glued together in the shape of a "T". The top piece is a square and the bottom piece has the proper angles sawn into each side. I think he sets his bottom piece into a shallow dado in the top piece for a little extra support, though, I'm not sure it would really matter. I believe he sells them on his website as well if you don't want to make one.

FWIW I use a sliding bevel, which works fine. I've never really felt the need for a special marking jig just for dovetails. Using the sliding bevel also lets you set the tail angle to whatever you want and not be fixed at whatever the two angles on the marking jig are. In addition, the downside to these jigs is that they are designed for marking a single piece at a time. If you gang cut your tail boards, the top part of the jig won't be long enough to square across the ends of multiple boards simultaneously, requiring you to use a separate square anyway.

ah - I just caught what you are saying and I have to ask the question - do you guys gang-cut your pieces?

[Robert Rozaieski]

ah - I just caught what you are saying and I have to ask the question - do you guys gang-cut your pieces?

When I can I do. It saves a bunch of time versus marking and cutting each tail board separately. Another benefit besides sawing fewer times is that you only mark the board face that is facing out, saving you marking time as well.

[Alan DuBoff]

He used to use the LN dovetail marker:

(linky pic)

http://www.lie-nielsen.com/images/d-mark_sm.jpg (http://www.lie-nielsen.com/catalog.php?sku=D-MARK)

Looks like the same gage to me, but hard to tell for certain in the video. You can make one of these pretty easy, or just buy one from LN.

[Brent Smith]

Looks like the same gage to me, but hard to tell for certain in the video. You can make one of these pretty easy, or just buy one from LN.

Or you can buy Rob's direct from him on his website.

[Alan DuBoff]

Or you can buy Rob's direct from him on his website.
Yeah, I see Rob has a slightly similar one on his site.

I guess he's gone on to bigger and better things than when he leveraged LN for success. :)

I like the looks of the LN better, although it costs more.

I use the Veritas markers, but others could buy them direct from Cosman's website I guess. ;)

Here's what I use:

http://www.leevalley.com/images/item/woodworking/markmeasure/05n6103s4.jpg (http://www.leevalley.com/wood/page.aspx?c=2&p=49424&cat=1,42936,50298&ap=1)

[Mike K Wenzloff]

I'll provide another "dissenting" voice alongside Robert's. Like Robert, I use a sliding bevel.

I have a few slopes (1:4, 1:5, 1:6, 1:7, 1:8, 1:9) that I "permenantly" marked into my benchtop that I set the sliding bevel to. I use a double square to extend the lines on the appropriate edges/faces of the to-be DT'd pieces (depends on whether I do tails or pins first). And like Robert, for like-sized drawers or carcass sides, I gang cut them.

fwiw, the design of the Cosman/LN/etc DT markers is an old one. If I recall, one of Wearing's books shows how to make one, but they are dead simple to make and one can see from a picture what they can be made like.

Oh...y'all do know how to layout for the slope of the desired markers, right? Easiest way is to use a sliding bevel gauge and a square...Ironic, isn't it?

Here are what the slopes mean expressed as degrees of angle.
Slope/Angle
1:9 / 6.34
1:8 / 7.13
1:7 / 8.13
1:6 / 9.46
1:5 / 11.31
1:4 / 14.04
1:3 / 18.43

At least if I still know how to use Excel...

Take care, Mike

[Brent Smith]

I guess he's gone on to bigger and better things than when he leveraged LN for success. :)

I like the looks of the LN better, although it costs more.

I use the Veritas markers, but others could buy them direct from Cosman's website I guess. ;)



Hi Alan,

I think the relationship was symboitic, at least up here in Canada. Rob's know how, combined with LN's quality tools made for an impressive one-two punch in sales.

LNs look better, cost more.... and BCT look even better and cost even more. I use the LV markers myself, or as Mike pointed out a sliding bevel.

[Alan DuBoff]

Mike,

Bevel works well, no doubt. I have one and use it but will most often grab for the LV markers, I like to have the flat on top, angle on the front when marking. I layout my dovetails like Cosman, so use dividers and poke a hole, which I put the pen in, that allows one to flush up the marker with the mark which the pen point rests in. This works well for me, and I get both marks at once.

With a bevel I get the front angle, but not the 90 degree across the top, so the marker lets me get both sides to be marked at once.

Funny though, I have a board in my shop which I use, and it has the different bevel degrees on it, so I can take my bevel and set it for 1:8, 1:7, 1:6, etc...and I have to admit I got that idea from your shop when it was at your house, you had showed me those markings on your bench. ;)

Truth be told I don't use my board as much as I had thought, just a matter of how I work and tend to grab the LV markers. If I had the LN I would probably grab it, or make one. There was an identical one pic'd in the Joyce book which Alan Peters revised, as I recall. That is most likely where Rob Cosman saw it, maybe not. He is certainly a big Alan Peters disciple and advocate.

[Al Navas]

Up until just a few days ago I used the sliding bevel exclusively to mark the dovetail layout on the tails boards. However, yesterday I started thinking about using a marker, and today I executed the idea: Make a prototype 14° dovetail marker.

It is amazing how much quicker I can now mark the tails, and extend the lines to a second board as I get ready to gang-cut:

http://sandal-woodsblog.com/wp-content/uploads/2008/11/dt-markers.png

It took me about 30 minutes to make these, including resawing the small original board. After machining I simply glued the tops to the angle templates using 2P10 adhesive (on the template) and activator (on the tops) - you can release finger pressure in 10 seconds, and it holds.

So far I am pleased with the results. I still prefer to do the layout using calipers, and then use these markers to complete the layout.
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[Derek Cohen]

As Frank Klausz is so fond of demonstrating, it is unnecessary to mark out the angles. I mark them because some angles suit better than others (for each situation), and I can judge this better in a concrete form. For thinner boards I prefer lower angle ratios (e.g. 1:5 or 1:6), otherwise the pin becomes too parallel. Conversely, for thicker boards I prefer a higher ratio (e.g. 1:7 and 1:8) otherwise it looks too wide. Dovetails are good joints, but these days they are mostly done as cosmetic additions.

It is not necessary to use a dovetail marker. You can use a sliding bevel, which I would imagine is a more time-honoured method. As some have found, a dedicated marker makes the task easier and more consistent (which can be a help in avoiding errors).

All the markers in the world will not help if you do not saw the apex line(s) square to the board. The angles do not make a whit of difference to fit (since the saw cuts act as templates to the mating board). It is the apex line(s) that count the most - anything that is less than straight will show up as a gap. So a marker must include this line as well (which is not on a sliding bevel).

I have used many of the marking gauges on the market (some given to me as gifts) ..

Lie-Nielson (1:7 and 1:8)..

http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/LNDovetailMarker1.jpg

Woodjoy (1:6 and 1:8) ...

http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/page9_1.jpg

I prefer the ones I make ...

1:7 infill in brass and Blackwood ..

http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/dovetailsaddle.jpg

.. or a simple 1:8 in Jarrah ..

http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Dovetailsaddlesquare6.jpg

More recently I made up a bunch of these for sale (none left and I doubt I will make more - too much work!) .. brass (1:8, 1:7, 1:6, and 1:5) ..

http://i13.photobucket.com/albums/a262/Derek50/Marking%20and%20Measuring/Dovetailmarkersinbrass_html_48e46b7.jpg

If you want to have a go at making the latter, here is a tutorial ...

http://www.inthewoodshop.com/ShopMadeTools/Dovetailmarkersinbrass.html

Regards from Perth

Derek

[Ken Werner]

Oh Derek, you are a hard act to follow...I have no shame though - here's my shopmade DT marker. I use it all the time.

http://www.sawmillcreek.org/showthread.php?t=61548

Ken

[Al Navas]

Derek,

Yours are terrific! But no way can I spend the time required to make them so beautifully. Maybe, just maybe, when I have nothing else to do in the cold of Winter... :cool:


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