Domino spacer gadgets

[Dixon Peer]

Has anyone had a problem with the spacing of repeated mortises using the hammer-head shark spacer gadgets?  I started with the machine set to the smallest mortise width for the first two plunges on two boards I wanted to join, changed the machine setting to the next larger mortise as is recommended, had the hammer-head pins both set at 130 mm and went on down the boards for twelve plunges.  The mortises did not line up.  So, I did the same thing on one piece, working from both ends to see how far off the slots would be after repeating twelve times.  The difference was 6.65 mm.  I see no way to adjust anything to correct for this.  If the machine is cutting the mortises just the smallest distance different from the left side than it is from the right, that difference will be cumulative over several feet.  For so much money for this machine, this is not something I expected.

 

[eweber]

I had a similar problem when I first started to use the cross stop on long run of dominos.
In my case the mortise were not always clean on the edges. Small chips of wood wood offest the pin. The errors would slowly accumulate...

I barely used the pins to space my mortise anymore and just mark my mortise and use the middle width setting.

Emmanuel

 

[Eli]

You also need to double check the pins settings, I did a whole bookcase and then discovered one side pin was set on a hill instead of in the valley where it belonged. That was approx 1mm difference from the setting it should have been. I always use the medium setting now, and enjoy the "Hammerhead" again.

 

[Warrior]

Dixon,

I have had the same results that you had. I have since placed them on a shelf where they collect dust.

I like the pencil mark method since you can place the mortisii where ever you need them and change the spacing on the fly. I also like to cut narrow mortisii on one side of a glue-up and medium on the other.

Eiji

 

[Dixon Peer]

One would think Festo would be a little embarrassed over this what with their reputation for quality tools.  My pins setting is not the problem; they are both at 130mm dead on. 

 

[Jim Force]

It appears the "error" is when you make over sized slots.
I ran the machine on the "tight" setting with a 5mm cutter, and did a string of slots. They measure 130 from the edge of the slot to the center of the new slot (140mm center to center.
I ran a second string of slots parallel, with the first slot tight, and the subsequent slots set to loose.

Forgive me I don't have my glasses with me today so I'm having a hard time reading those millimeters, but the loose slot is 5mm wider than the tight slot and this introduces a 2.5mm error on the cross stop.
You set it to 130 edge to center and it machines slots 140mm center to center when tight, and 142.5mm center to center when loose. The subsequent slots are 2.5mm further apart.

I choose the pencil method as well. If ever you need a loose slot, it is when you machine a long joint.

 

[Dixon Peer]

But Jim, if you start with the "tight" slot on both boards, on a pencil mark you make when they are together the way they will be assembled, and then change to the next larger slot ON BOTH BOARDS and use the hammerhead attachment to step down both those boards, the relative position of the slots should be the same.

 

[CharlesWilson]

But Jim, if you start with the "tight" slot on both boards, on a pencil mark you make when they are together the way they will be assembled, and then change to the next larger slot ON BOTH BOARDS and use the hammerhead attachment to step down both those boards, the relative position of the slots should be the same.

That's the way I've done it. It worked fine for a 6' join.

Charles

 

[Dave Ronyak]

I tried the "hammer head" fixture a couple of times when making cases from 3/4 plywood.  Both times, despite my trying to be careful to not trap any chips, my slots were off.  It took me far more time to correct these errors than to simply mark both pieces with a pencil then eyeball the marks.  I've had no assembly problems using the "pencil mark" technique even when all the mortices are made using the narrowest setting on the Domino machine.  I may try this fixture with solid wood, but not likely again with plywood.  Plywood tends to have more splintering when mortising into one of the veneered faces than into an edge face.

Dave R.

 

[Tim Sproul]

Has anyone had a problem with the spacing of repeated mortises using the hammer-head shark spacer gadgets? 

I've used the cross stop on a few plywood cabinets now.  These typically involve 12 - 24 butt joints per cabinet (mainly because of the drawer dividers).  The cabinets have been base units so ~24 inches depth.  I cut 5 mortises per butt joint and use the middle width setting except for the mortise closest to the front which is the reference and cut to the minimum width mortise.  No equipment problems with alignments in my experience.  I do get 'chads' if I plunge too quickly but like any mistake made in joinery, you have to go and fix it before continuing on if you use that surface as a reference (keeping a small round file/rasp on hand is great for this or for plywood, I use a small diameter dowel wrapped with 80 grit).  I also cut medium width mortises on the mating mortises, that is, for a given place where a single domino will be used, both mortises for that domino are medium width.

I do find that there could be some minor improvements with the Domino system:

1.  chamfer or roundover the endgrain of the Dominos.  Makes for easier assembly of the joint....doesn't really affect getting the Domino into the first mortise but when you've got 25 Dominos (a line of 5 Dominos and 5 lines) to get all aligned before the assembly will allow all the joints home...a little bevel on the ends of Dominos is very helpful.  For the price we pay for those little pieces of wood....the bevel/roundover should be a piece of cake albeit a nightmare for the person who has to design the machinery/workflow to get this done.

2.  The cross stop should have been made with polycarbonate or acrylic or another clear plastic instead of the black stuff or at least a window of the clear plastic.  It is ALWAYS helpful to have visual confirmation that the cross stop pin is at the end of the mortise.  The little sticky pads on the Domino face sometimes allow you to position the Domino so the cross stop pin isn't at the end of the previous mortise because those sticky pads don't let you easily slide the Domino across the work (knife cuts both ways...).  I know I've cut a mortise or two a bit short of the intended position because the cross stop pin did not get to the end of the mortise like I intended.

 

[Eli]

I would have liked if they were alloy instead of plastic, and attached to the fence more securely.

 

[Tim Sproul]

I would have liked if they were alloy instead of plastic, and attached to the fence more securely.

Eli,

I rather like that the attachment strongly favors the base of the Domino.  Say you drop the Domino while the cross stop(s) is attached.  Would you rather have the cross stop break but leave the Domino relatively unscathed or would you have the joint for the cross stop crack/break because the cross stop was too strong?  Me?  I would rather replace just the cross stop.  You?  You don't worry about it because you don't like the cross stop so it isn't attached to your Domino  !

 

[Warrior]

I personally will not drop my domino. it is deffinately my baby and I always make sure it is placed in a position and location that is safe from falls.

 

[Eli]

You?  You don't worry about it because you don't like the cross stop so it isn't attached to your Domino  !

I do like the cross stop. I use it every other time I use the Domino. Not anti at all.

I'm super extra careful about how I lay it down. I put it upside down in the hose garage, with the business end away from me. I don't even move away from it until I make sure the hose isn't wrapped around my leg.

I would still rather the cross stop was stiffer. I understand why they are plastic, but they have a bit of flex and the attachment point isn't as solid as I'd like. I agree with you, it would probably crack if dropped if they were alloy.

 

[Tim Sproul]

I personally will not drop my domino.

I don't plan on dropping mine either.  But I don't plan on cutting mortises on the wrong face of a leg either..... .

 

[kdi]

Have had the same problem.  In addition,  I don't think the "hammer heads" fit into the base all that well.  On mine the rt side stop doesn't lie flat (in the same plane as the cutter, lt side is ok) when tightened and requires a little down pressure on the domino to ensure the fence is tight against the work piece.  Put another way I had a line of hole that didn't line up across two pieces and the line wasn't straight on the individual pieces. 

I assume it must be me, but like most of the others, I mark locations, use the intermediate width setting, and don't use the "spacer gadgets" either.

 

[cflansbaum]

it's not you... same thing with mine...

 

[Dixon Peer]

Well, I talked to Festo service and they are going to take a look.  They're sending me a pick up ticket for UPS, and the machine will go back to them.  I'm told it'll be back in a few days and it will work with the "hammer-heads" as it should.

 

[CharlesWilson]

Well, I talked to Festo service and they are going to take a look.  They're sending me a pick up ticket for UPS, and the machine will go back to them.  I'm told it'll be back in a few days and it will work with the "hammer-heads" as it should.

Make sure you send the "hammer-heads" with the Domino. I ended up having to 'recalibrate' mine so that they fit correctly.

Charles

 

[Dixon Peer]

Well, I talked to Festo service and they are going to take a look.  They're sending me a pick up ticket for UPS, and the machine will go back to them.  I'm told it'll be back in a few days and it will work with the "hammer-heads" as it should.

Make sure you send the "hammer-heads" with the Domino. I ended up having to 'recalibrate' mine so that they fit correctly.

Charles

Yup, they're sent.