Those bench dogs yet again....

[Alan Schaffter]

Thanks Alan, that sounds straightforward enough.

I seem to remember reading a piece somewhere which suggested that wire clips with time wear a groove in the dog hole - this was pitching the view that the flat spring strip is one of the advantages of the square type. I'm presuming you haven't seen anything like that.

Even if it was to become an issue over time, I'm sure it's possible to come up with a wide area spring for a round dog - although the big advantage of a wire spring is probably that it reduces the cross section of the dog by only very little.

ian

Havent' seen it yet. Again the spring doesn't need to be strong, it just needs to provide enough pressure to keep the dog from slipping down from the force of gravity. Only a bump or curve in the spring contacts the dog hole, so even if it does wear slightly it will likely be midway down in the hole where the bump is and then only if I use the same dog holes all day, every day. Also, I put a tiny chamfer on the top of the dog holes, making it less likely you would see a wear spot at the bench top. All this, of course applies to a hardwood top- a softwood top might indeed show some depression or wear if you used too strong of a spring.

By the way, here is a discussion of round vs square dogs by Jameel Abraham, designer of the superior quality "Benchcrafted" bench hardware. Very few of his points seem significant to me with the exception of - the metal vs wood issue when using a hand plane (if you are careless) and the ability to add round holes at any time, especially in vise jaws- a common occurrence.

In the other, round dog, camp is Chris Schwarz woodworker, author, lecturer, hand tool afficionado (zealot?), and former editor of Popular Woodworking Magazine. Here is what he says . There are some pics of his round wooden dogs- he uses bullet catches.

Here is a way to make round dogs - uses a flat instead of a groove for a flat metal spring.

Here is one that uses a flat wooden spring.

[ian maybury]

Thanks Alan, good stuff. I initially read the topic up about a 18m ago, and influenced by Chris Schwarz decided on a hardwood (European beech in my case) Roubo with round dog holes. For the reasons he lists in your link - ease of addition of holes, large range of available accessories, ease of making, and possibility of use with holdfasts.

I concluded that square dogs were probably as much a matter of fashion/coming from a specific tradition as anything, and that if they have any advantage it's probably in the specific task of securing work for hand planing using a tail or wagon vise. But that they were a less flexible solution so far as holding other stuff is concerned.

This post came about because since then the Benchcrafted guys have gained a lot of profile, and there's been a lot posting of people using square dogs. I started to wonder if there wasn't some basic functional reason for this beyond fashion. Like strength, basic gripping ability or ease of use. The square dogs are for example quite a lot stronger due to having a larger cross section, especially compared to a 3/4 in round dog that's had a flat machined on it - which of course doesn't matter if the 3/4in round dog is strong enough. Square dogs likewise lend themselves to having an effective flat spring fitted.

The positive feedback about round dogs following my initial post seems to suggest that people are doing just fine with the round type, and that despite there probably being more of this type out there that there's no significant negative comment about.

So that barring negative feedback before then it's looking like it's round dogs for me when I get started on the bench in the next few weeks...

ian

[Joe Leigh]

Ian,

If you are going with round dogs because they are easier, then you are making a mistake. Why is easier even in the discussion? If this is a "lifetime " bench for you personally why make compromises? Sure the square dogs are harder, a lot harder, and require more technique, skill and a lot more time to complete. Isn't that the point? Improving and learning while you build your bench as well as after you complete it? It took me two days to accurately make the jig required and to route out the dog holes and another day to fabricate 16 dogs. A very small investment in time considering that I have 3 months invested in my bench so far and at least another two to go.

Just my $.02

[ian maybury]

Don't read this as saying the decision is made Joe, but the biggest reason I can figure for going round is that I'm keen to keep open the possibility of a pretty comprehensive dog grid on the bench top - to help with clamping awkwardly shaped assemblies like say laminated curves. There will also be a sliding deadman and possibly some holes in the legs and edge of the top to help with clamping on the front face. It seems a pity to pepper a bench with redundant holes, so I was hoping to add some of these as I went along.

Against that the square dogs seem to work really well with a tail or wagon vise to hold flat and square pieces for hand planing on the top. The problem with that though is that the traditional single row of square dog holes doesn't cater for the above. Not only that, but the 3 deg slope used on many square dog holes doesn't make them very adaptable to other tasks either. Mixing round and square holes seems possible but somehow awkward too.

I subscribe 100% to your point that there's no point cutting corners on what will be a lifetime job, but the 'easy' in this case is perhaps the ease of addition of extra holes after the top is built rather than labour saving - although I'll not turn my nose up at that either if the latter comes with no penalty.

That said, maybe there's an alternative way to obtain the above function?

My major caution about round dogs relates to the 3/4 in diameter - I've a sneaking feeling that something more like 1in would be more robust, and leave more options opening for putting flats on them etc. I've a feeling that a nice close fit in the bench holes to prevent tipping may be important too.

One problem with doing this is that so many accessories (Lee valley bench dogs and the like) use a 3/4 in shank. Steel holdfasts are usually 3/4 in in diameter, but you do see pictures of them used in quite loose fitting holes. http://www.flickr.com/photos/coaland...57625264696890 I wonder how the latter would get on in a 7/8 or 1 in hole in a good thick bench top?

ian

ian

[Alan Schaffter]

Ian- I agree with your very thorough analysis. I just have a few comments-

How much shear force is typically put on dogs? I would think enough force to snap a dog would also damage the work. I doubt it is necessary if the dog is made from good straight-grained hardwood, but I wonder if it would be possible the put a steel core in a wooden dog?

I forgot whether you have purchased your vise hardware, but since you mentioned the BenchCrafted wagon vise I'm thinking you are looking at the "good stuff." Have you checked out the Hovarter vises? Hovarter started with a simple face vise but now makes a full line of bench vises. They use a totally new mechanism that has a solid rod(s) instead of a lead screw, are quick acting, lock tight with less that a half turn of the handle, etc. The Hovarter twin screw (twin rod) vise and leg vise are totally rack free and the lower fulcrum on the leg vise adjusts and locks automatically! They are pricey like BenchCrafted.

Here is the link to the Hovarter web site. You gotta see it in action. There is a video of the the twin screw (rod) vise on his website but there are videos of his other models on YouTube.

I have never seen a Hovarter vise in person, but I love technology and am a tinkerer as much as a woodworking. If I had the $ when I built my bench, I would have used Hovarter Vises.

[Joe Leigh]

Well, the bottom line is that you have to make the decisions based on what type of work you do. Just ask yourself how often do you work with od sized pieces? 95% of the work I do is rectangular in shape and since I haved commited myself to using hand planes, the square dogs just seem right to me. Also, I've seen otherwise beautiful benches littered with rows of 3/4" holes like some horizontal pegboard.

Just a word about hold downs, you need to be aware of your top thickness if you plan to use them. Most Roubo bench plans call for a full 4" thick top and that can be problematic for the holding power of a hold down. Check with your specific manufacturer to see what thickness works best for them.

[ian maybury]

What seems to be coming through from most of the posts here Alan is that 3/4 in dogs work just fine, the above is just my gut talking. I've seen the bench top thickness issue mentioned in connection with holdfasts too Joe. Test holes are probably advisable - it seems the things can be very unpredictable. I've a sneaking feeling as above that part of the issue is that they need to tip a bit in the hole to get a grip, and that a looser hole might work in a thicker bench top.

Part of the problem in my case is that I'm not well established enough as a woodworker to be able with any great certainty to be able to predict exactly the type of work that's I'm likely to gravitate to over time. Hence my attempts to keep some options open, although this isn't always a good move. Jack of all trades etc.

I've seen the Hovarter vise Alan, and it's very nice - but think I'm at this stage for budget reasons committed to the Veritas twin screw I've bought. I bought a front vice for the end, but have been put off by the risk of racking if it's used with a wide jaw and dogs. Right now it's between going to a DIY wagon vise in a format similar to the Benchcrafted, and rely on Veritas type dogs etc for more complex holding tasks - or possibly but less likely use a Record 52 1/2 I have with a wide jaw and dog holes. The Veritas quick release tail vise is another possibility, but again one requiring budget.....

ian

[Alan Schaffter]

Well, dang, we need somebody to install and do a report on the Hovarter!

[Greg Hines, MD]

I have round dogs in my bench, and instead of a tail vise, I use a pair of Veritas Wonderdogs to hold boards on the flat to rout edges or sand, and have had no trouble with them at all.

Also, there are plenty of different accessories that are generally easier to make with round dog holes. Lots of people make planing stops with a pair of dowels, and a board as the stop.

[ian maybury]

I'll happily go guinea pig for you guys Alan if you'd just like to organise a little whip around there to get me set up....

Thanks Greg, another devotee of the round route....

ian