Incra Ultra Problem

[herdsman]

Hi Guys,

I wonder if anyone can offer me some advice with a problem that I have with an Incra Ultra 25. I bought the Ultra about two months ago and have fixed it to my router table, I have checked that the table is flat and the fence of the Ultra is square to the table.

I made the dovetail bit and template selection according to the instructions, centred the bit and set the template accordingly. The stock used for centering and the test cuts is the same width and square, the bit height was set according to the instructions and a test cut was made (quite a few in fact) but the result is rather disappointing.

The depth of cut seems fine but there is a gap of approximately 3/64 of an inch between the mating edges of the dovetail. I can only eliminate this by moving the Ultra to the next position and then adjusting to remove the error but this is not how I expected the system to work.

Any ideasPic

 

[motownmartin]

Herdsman, have you thicknessed your boards to a fraction less than the depth of your cut :?: have you made sure your clmp is fully locked :?: there are 2 locking positions (you probably already know that) is the cutter the correct angle e.g. 9 degrees :?:

 

[herdsman]

Hi Martin,

I've checked so much so many times...

I have looked at the jig components to check that everything is tight, it appears that something is moving before the cut is made. The jig moves the correct distance every time but the cut is in the wrong place. I have even tried using two clamps and that does not make any difference.

I have tomorrow off work and I will spend the morning looking at this again when my eyelids are not so heavy!

I tried to suply a photograph but that did not work...

Paul

 

[motownmartin]

I'm not sure what the problem is, maybe tomorrow when you re-approach the problem you will see the error.

Good luck

 

[RogerS]

Is it the LS (lead screw version) or the one with teeth? If the latter are you using metric or imperial teeth (green or black)? Not sure if that would be the answer..just a stab in the dark.

 

[Ian]

Hi Herdsman

If the dovetail is a very loose fit even side to side raise the bit until the play is removed the higher your bit the tighter the fit.

Have you removed the play from your right angled fixture with the nylon screws as this might be your problem, I have the ultra and in the early days of cutting dovetails using a plunge router I had lots of problems with joints not fitting and found out it was the router, with the stress of the cut and the vibration would make the router slide down the plunge posts causing tons of problems.
I now have a fixed base router which is the dogs.
As Roger said this is an imperial system and if you are using the metric teeth this will not work with the templates.

Ian

 

[herdsman]

Is it the LS (lead screw version) or the one with teeth? If the latter are you using metric or imperial teeth (green or black)? Not sure if that would be the answer..just a stab in the dark.

Hi Roger,

I am using the imperial version (black teeth) and the jig is not the latest LS version.

Hi Ian,

The depth of cut seems to be fine it is the spacing of the dovetails that is the problem. I have cut four sides this morning and the results are a bit od, the pins and tails have gaps between them, some on the left side some on the right side and some on both sides.

I did wonder about the router, currently using a Triton 1400 watt model

Paul

 

[Anonymous]

Paul

I had similar problems first time I tried this on my Ulta. The height of the cutter is everything when cutting dovetails and that is probably the source of your problem.

you need to make very small adjustments until it works.

 

[motownmartin]

Is it the LS (lead screw version) or the one with teeth? If the latter are you using metric or imperial teeth (green or black)? Not sure if that would be the answer..just a stab in the dark.

Hi Roger,

I am using the imperial version (black teeth) and the jig is not the latest LS version.

Hi Ian,

The depth of cut seems to be fine it is the spacing of the dovetails that is the problem. I have cut four sides this morning and the results are a bit od, the pins and tails have gaps between them, some on the left side some on the right side and some on both sides.

I did wonder about the router, currently using a Triton 1400 watt model

Paul

It sounds as though something is loose if the fault you're getting is incosistent, or the template is wrong, which I doubt, what template are you using :?:
You'll have to learn how to post photo's, it's difficult to see what you mean without some pics.

 

[Ian]

HI Herdsman

I would say depth of cut, raise the bit until you can't get the tails and pins fitting (to tight) and then lower a fraction at a time and I mean a fraction.

Ian

 

[motownmartin]

Paul, as Ian & Tony says, raise the bit, for instance, if you have 1/4" thick material cut with a 1/2" cutter, you will have to raise your cutter to about 5/16" so you have the pins & tails protruding about 5/16".
This should close the gaps between the pins & tails, if it doesn't you must have something loose.

 

[motownmartin]

Paul,
I thought I would go to the workshop to try and show what happens when you raise the cutter.
Here are some photo's

The cut when the cutter isn't high enough

The cut set higher (about 9mm) still not quite there, but very close.

It looks as though the cutter should be set to a height of about 10mm for a 1/2" cutter, hope this helps.

 

[Ian]

yes thats a good example don't just go by what the instructions say on cutter depth every bit is going to be slightly different and tests cuts for setup are needed

Ian

 

[herdsman]

Hi Martin,

That is exactly the problem. Obviously I have tried to be too careful at setting the depth, I did try to post a picture but it was not successful.

Thanks to all who have contributed to this post. I shall play in the workshop tomorrow and increase the depth of cut.

Paul