Setting Up a Dovetail Machine

Tips on the tricky parts of dialing in an OMEC dovetail machine. October 15, 2010

Help! I just purchased an OMEC 750 dovetail machine and I can't set it up properly. The machine is made in Italy, so with the language difference it is impossible to get any info from them. It is supposed to be quick and easy to set up and capable of producing 40 drawers an hour. So far I have produced one which has been satisfactory.

Forum Responses
(Solid Wood Machining Forum)
From contributor R:
There are a few key components to setting up this machine. First you need to set up your left and right fences to the correct offset. The offset should allow for the anti-splintering device to act as a chipbreaker behind the vertical piece, otherwise you will get tear out.

Once you have your fences set up to reflect the 12.5mm offset (which is half the width of the dovetail spacing 25mm), run a piece. Other adjustments include height adjustment of the cutter, mortise and tenon adjustment, and the eccentric cutter. After the fences, run the machine with all 4 drawer pieces. Ensure the offset of the fences is correct.

Once you have this, move to the next station, which is the height of the cutter. Then check the tightness of the joint. The bit is eccentric, so you can adjust it in the chuck to loosen or tighten the joint. You should be able to put 2/3 of the dovetail together, and the pressing will take care of the rest. There is also the mortise and tenon depth adjustment.

You will have to take a little time in setting it up, but once it is done, you should not have to adjust it again for quite some time. We (Cantek) sell a similar machine and I would be happy to send you our manual which you could use as well. Our technicians can walk through this procedure with customers over the phone and have it running in short order. It will take a little time, but you will get it.

From contributor M:
Call Macosser, the importer of Omec - they would be glad to email you the manual for the 750. Contributor R also gave some very good advice to get you going on it over the weekend, and that was a pretty generous offer to let his techs work with you.

From the original questioner:
Thanks - much appreciated. This is baffling me: The instructions I have suggest that you start by placing the cutter against the minus index on the eccentric chuck. It then says that every indent on the chuck represents 1 mm of height adjustment. Surely this is incorrect, as the eccentric scale changes the width of the dovetail, not the height? Surely it would be better to set the height of the dovetail first and then tweak the eccentric scale next to ensure a tight fit - which is what you have kindly suggested? If this is the case it is extremely frustrating doing it the other way around, which is what my instructions are telling me to do!

Am I kidding myself to assume that I can get both side and fronts and backs of the drawers to line up perfectly during the machining process, or will there always be some cleaning up afterwards? Is the alternative to use different timber widths to disguise this?

From contributor M:
Set the height of dovetail bit first. 3/8" or 10 mm is a good height. Then you use the eccentric to tune in the fit of the dovetail itself. Once you get your side fences set perfect, you should always be able to get flush joints. This assumes that all your stock is the exact same width and that it's been cut square.

From the original questioner:
Thanks! I will get the magnifying glass out and start tweaking things.

Is it best to cut the grooves for the drawer base before or after machining of dovetails?

From contributor M:
In most instances it doesn't really matter. I prefer to groove for the drawer bottoms after machining, because on those instances when I place the groove for a 3/8" bottom reveal, the bit comes very close to the groove, and with the material already removed for the groove, I get some blowout due to lack of support behind the pin.