Yea, Yea I know.. perfectly centered dominos.

[afish]

So, I already know Dominos and Dowels dont "have" to be centered. However there are times when it is needed or useful.  In my need to make room for other toys in the shop. I need to get rid of my doweling bench with the pneumatic clamps I had posted in other threads. So, I needed to be able to accurately center my dowels and have a precise dimension off of the one side since I end drill with the ddf40 and it needs to match the holes I drill on the face with the cnc using the fence.  It also comes in handy if you build exposed domino drawers.  Either way I know some have expressed interest in the best way and I think I have found it.  I used to use the depth rod on a caliper before but the Mafell has a gap and chamfer on the fence next to the face so its hard to get the depth rod to land on enough surface to get a good measurement. 

So, I made this holder for a digital dial gauge.  The digital works better for this as you can zero it when compressed and get a measurement as it falls which is what you need for setting the fence on either machine.  I made the holder universal so you can flip the dial indicator over to measure while its being extended or compressed.

The formula is pretty easy.  Take the material thickness and divide by 2 = X  Then take the distance from the bottom of the plate to the center of the cutter (10mm for domino and 9.5 or .374" for the DDF40) and add that to X = What the dial should read. First test cut I read .001 difference from one side to the other. So, about .0005" error. Figured I could live with that so left it alone. I used 8mm tool steel rod inserted into 8mm dowel holes with a 123 block to take the measurement.  Seeing as how the fence is out .003 on my ddf40 from the left to right side, That's easily within tolerance for me. 

Now that I'm typing this it occurred to me to reverse it so the dial reads while being compressed and make a smaller dial holder that could be clamped onto the fence instead and the indicator would measure on the base. It would make it slightly easier as it would free up one hand instead of using one to hold it onto the dial holder. Oh well, v.2.0 I guess. 

 

[smorgasbord]

Isn't that just a homemade version of a digital height gauge? Like this:

[attachimg=1]

IGaging 6" Digital Height Gauge

 

[afish]

Sort of, the height gauge you posted will not read below the reference surface.  The one I made will read both above and below the surface of the reference surface. Makes quick work of measuring dado and rabbit depths too. and mine only cost 27 bucks for the dial and a piece of scrap I found on the floor but I see yours only cost 40ish so I guess its debatable which you might prefer.  Both have their place but I consider a dial indicator more universal, accurate and more of a staple in any shop.  Dial indicator and caliper are the 2 most common and important in most home shops.  I doubt most have a height gauge like that in their shop. 

 

[Bob D.]

"I doubt most have a height gauge like that in their shop. "

I have one from Wixey and it's handy to have for layout but
use it more on metalwork than wood.

 

[Birdhunter]

I have a Starrett depth gage that should replicate your system directly.

 

[simnick]

Good point about measuring off the bottom like that to center dominos more precisely, but basically, you made a depth gauge. I have at least 6 devices that can act as a depth gage.

 

[afish]

Yes, I realize depth gauges already exist and come in many forms and there are multiple ways to make a depth measurement. from the simple caliper to more adjustable and cumbersome apparatuses with magnetic bases (which are useless for this task) to things like what's already been posted above. All have their pluses and minuses. I have no doubt that there is at least 6 different types, congratulations on owning so many and that only proves that there isnt a one size fits all depth gauge instrument. I have seen few that measure both above and below the reference surface quickly and easily and provide a large stable base.  There are those like pictured below that can do both above and below but I dont like the small footprint of the base since only one foot could be used and would be subject to tilting and giving a bad reading not to mention harder to hold. It starts to get tricky for me to hold and adjust the tool and manipulate the fence to within a few thousands with just 2 arms. 

The dial indicator has the added benefit of being spring loaded so there is no need to manually adjust or slide anything like the other depth gauges either.  Simply place on the base and then twist the height adjustment knob for the fence to dial in the height, you get instant reading opposed to moving the fence and then having to go back and slide the gauge around and take multiple different readings. 

The post was less about the holder and more about the process. "forest for the trees" people, feel free to insert/use the depth gauge of your choice to take the reading and by all means if you have a better depth gauge for the process please post with photos so I can learn.

 

[Bob D.]

I see the advantage of your setup [member=73094]afish[/member] and the ability to read both above and below the surface is useful. Unlike many commercial versions yours rests on one surface and lets you reach out over the edge to take a measurement.

 

[greg mann]

The concept is elegant in its simplicity. I suppose another approach, if you often use the same materials a ‘gage block’ of the correct thickness could be used to just drop the fence down on.

 

[afish]

The concept is elegant in its simplicity. I suppose another approach, if you often use the same materials a ‘gage block’ of the correct thickness could be used to just drop the fence down on.

Yes, That works too.  I actually posted awhile back about that HERE Problem is I still run into some supply chain issues in my area and the material I get isnt always consistent.  I use 2 different plywood dealers and HD when I get desperate. The stuff I get between the 3 of them can vary a fair amount.  So I was looking for a quick way to dial in the ddf40 or domino if I need to change it. However the Domino stays in its case most of the time since RB can be hard.  I started using metal drawers most of the time. 

I already made v2.0 to be able to be held on with a 2" spring clamp to free up my other hand.  Ran another sample and was out .002 so .001 of error.  I made two boards and put the 2 together and then flipped one.  I could not feel any deviation by touch on 3/4 melamine in either orientation so Im happy with that time to move on to the side to side jig now.