Design principles of Qwas Dogs

[DrD]

[member=2022]Qwas[/member]

Steve, been using your Dogs and Square for a couple of years now with total confidence.  As an engineer, I checked their "squareness" on both of my MFT/3s and was completely satisfied.  Having said all that, I too look forward to your educational video, as I know I will learn and benefit.

Keep up the good work, and any word on new stuff?

 

[Qwas]

Thanks for the encouragement.  [smile] I've been so busy with making dogs that woodworking disappeared for a few years. My MFT has become a powder coating and quality control table. In November I was able to get away for a few days for my nephew's wedding and it felt good to away from the dogs. The last week was spent on a new TV stand and that's been the first use on MFT for woodworking in several years.

So, there is nothing in the works right now but that could be subject to change before year's end.  [smile]

 

[jamanjeval]

I will try to make a video in the next few days showing the difference. You may be surprised at how others missed how my dogs actually work and the "magic" involved.

Awesome! [thumbs up]
Thank you for sharing with the community.
I look forward to learning about them!

 

[Birdhunter]

I checked all 8 of my Qwas dogs in a number of MFT holes with a Woodpeckers square. All were completely true. No slop wiggling the square in the 90 degree dog pattern. The square nestled solidly every time. Pretty darn good. Rotated the dogs. Still solid. Not a statistically scientific test, but it convinced me that my 8 Qwas dogs are true and my MFT holes are true.

It would be neat to have some stainless Qwas dogs. I'd buy a few pairs.

 

[Qwas]

Thanks for the 8 dog test.

I hate to tell you but I don't believe in stainless steel dogs or stainless steel on the same bench as power saws. Aluminum dogs are very forgiving when accidentally cut into. When stainless steel hits a moving saw blade, you can have carbide teeth flying off, bent saw blade or arbor, and a saw flying back at you with possible injuries. It's just not worth the risk.

 

[Birdhunter]

Good point. Aluminum it is.

 

[Cheese]

I hate to tell you but I don't believe in stainless steel dogs or stainless steel on the same bench as power saws. Aluminum dogs are very forgiving when accidentally cut into. 

That's the reason that Lee Valley's version is made from aluminum & Woodpeckers' version is machined from Delrin.

 

[John Bates]

I think the Lee Valley ones are stainless steel.

 

[IanB]

Lee Valley has aluminum ones (they call them 'surface dogs') included with their MFT clamping kit.  They have stainless ones too, as Parf Dogs.  (I may have spent too long looking at their products...)

 

[RuhiA]

When stainless steel hits a moving saw blade, you can have carbide teeth flying off, bent saw blade or arbor, and a saw flying back at you with possible injuries. It's just not worth the risk.

Excellent point but what kind of circumstances would bring the moving saw blade near the dogs which are supposed to be used  to align the work piece with respect to the guide rail unless they have another use, such as marking where the kerf is going to be?  [scared]

 

[Svar]

When stainless steel hits a moving saw blade, you can have carbide teeth flying off, bent saw blade or arbor, and a saw flying back at you with possible injuries. It's just not worth the risk.

Excellent point but what kind of circumstances would bring the moving saw blade near the dogs which are supposed to be used  to align the work piece with respect to the guide rail unless they have another use, such as marking where the kerf is going to be?  [scared]

Hand planing when dogs used as stops. Not a saw, but still one of the uses. Aluminum typically will not damage plane blade.

 

[RuhiA]

When stainless steel hits a moving saw blade, you can have carbide teeth flying off, bent saw blade or arbor, and a saw flying back at you with possible injuries. It's just not worth the risk.

Excellent point but what kind of circumstances would bring the moving saw blade near the dogs which are supposed to be used  to align the work piece with respect to the guide rail unless they have another use, such as marking where the kerf is going to be?  [scared]

Hand planing when dogs used as stops. Not a saw, but still one of the uses. Aluminum typically will not damage plane blade.

Sorry, my mistake. I thought he was talking about rotating saw blade, carbide teeth flying off, bent saw blade or arbor, and kickback resulting the saw flying back at the user.  [wink]

On the other hand, anyone who rides their hand planes on a metal, steel or not, should not be allowed to be near any sharp objects, rotating or not. [big grin]

 

[John Bates]

When stainless steel hits a moving saw blade, you can have carbide teeth flying off, bent saw blade or arbor, and a saw flying back at you with possible injuries. It's just not worth the risk.

Excellent point but what kind of circumstances would bring the moving saw blade near the dogs which are supposed to be used  to align the work piece with respect to the guide rail unless they have another use, such as marking where the kerf is going to be?  [scared]

Unfortunately I've done it myself, luckily my dog was aluminium so no harm done apart from a scarred dog! [sad]

 

[Qwas]

Thanks John, I was just going to jump in and say I've had 3 customers tell me they accidentally hit a dog while using a power saw. There was a post on this forum about someone hitting a stainless steel dog too. Luckily, nothing bad happened. Like most others, I have no idea how it could happen but it does. That's why I consider it a good procedure to keep all stainless steel off the bench.

 

[Qwas]

The video is up and running. You can see I'm not an actor, or script writer, or a video editor.  [smile]

What Makes Qwas Dogs Different

 

[Birdhunter]

Thanks for making this video. Very informative. I am a Qwas customer and will stay one.

 

[yworkcb]

  Well done !

 

[RuhiA]

Excellent point regarding how the dogs are lining up referencing from the farther point of the circle of the holes. When you place one circle in another larger circle, there will be only one but only one point of contact. On the other hand, the reference point is not obtained from the cylinder's face inside the hole but from the protruding head. If the head is not concentric to the cylinder below within the hole, it will introduce an error, as large as the magnitude of the offset is in between the two cylinders. I think this is how this discussion ensued; non-concentric head.

Regarding the balls; they would require the largest diameters of the balls making contact with the straight edge. If the edge is thinner than the height of the largest diameter of the ball, they won't work.

 

[Qwas]

There are several reasons why the balls will not make a good set of dogs. As the hole gets smaller, the point of contact with the workpiece gets higher. But the holes on a MFT don't vary as much as my exagerated example. In my example, the holes varied by 1/4 inch in diameter.

But the bigger problem is the small point of contact from the ball. This small point could end up at a void in a plywood workpiece or a small valley in other wood surfaces and this will lead to new errors that might not be obvious at first. Also, it takes little pressure for the balls to create dimples on the wood which will lead to errors too, and more sanding.

 

[DrD]

[member=2022]Qwas[/member]

Steve, tried several times today but can't get your video to load.  I'm clicking on the arrow to initiate the video and get a gray screen with snow and a loading error.

Any help would be appreciated.

Don