Thread: Jointer to a specific depth in mm?

If it's a straight scale where all the divisions are equal, I'd be willing to have a go at making one on the CNC at work as long as you can send me the original (exact dimensions would also work if you can't take it off).

I think you will find that those gauges are only relatively accurate.

To start with, when set to the zero point, we now assume the infeed table, the knives and outfeed table (to a lesser degree) are all kerzactly aligned. If not, your zero point is out by the delta.

If the tick marks are 1/32 of an inch, can you not call it .8 of a mm and do the maths ?

I have used my jointer to created 45 degree bevels on 1/2 inch thick stock, and I did it in multiple passes ... not a single pass of 17mm.

The way I'd do it is with ZERO maths.
Glue a thin piece of bright Al plate over the scale and scratch mark an angled line on the Al
It does not have to match the same angle as the existing scale as you will recalibrate the thing from scratch with a micrometer
Start with the tables at the same height and mark a zero at the pointer, then systematically lower the indeed table a 1/2 mm at a time and measure the difference between the two tables with a micrometer and mark a scratch or punch a mark on the Al.
It's not like the scale and pointer on those machines are high resolution to begin with.

FWIW the angled scale divisions should be depth of cut divided by sine of the angle.

While we're on the topic of buzzing bevels, you have to be very careful to ensure that your both the fence and timber are completely flat and straight and that you don't flex anything by applying too much pressure while you work. If you do, you can introduce curves into the angled surface and that's a whole world of pain to try to fix.

Originally Posted by elanjacobs

If it's a straight scale where all the divisions are equal, I'd be willing to have a go at making one on the CNC at work as long as you can send me the original (exact dimensions would also work if you can't take it off).

Thanks a million. That is a very kind offer.

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Originally Posted by BobL

FWIW the angled scale divisions should be depth of cut divided by sine of the angle.

So what you are saying is that apart from being diametrically opposite the correct calculation I was spot on![emoji12]

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Originally Posted by DaveVman

Thanks a million. That is a very kind offer.

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No guarantees of success, but I'll give it a shot

Originally Posted by DaveVman

Hi Ian, I am researching because this is new to me. I have only just recently come to understand that a jointer can do more than make one face flat and one edge square.
As important as that is, it is a lot of money for one function.
For example, I don't have a proper table saw so I can't cut bevels on it. I have a project idea that requires 13 degree bevels and the parts are too long for my SCMS.
Someone suggested to me that I could do that on a jointer. Even showed how I would do it on a cheapie. When I thought about it, I realised it would probably be a better result in this instance than a table saw anyway.
Suddenly I realised there are other uses for a jointer that I hadn't thought of.
Then I started looking at the $600 jointers.

a word of caution here.
The fence on a lower cost jointer can usually be set to a reliable 90 degrees, and often also to a reliable 45-ish degrees, using built-in stops.
However, my recollection of forum posts is that it's rare for the fence on lower cost jointers to reliably hold an in-between setting like 77 degrees (which would correspond to a 13 degree bevel).
For a number of reasons I have a preference to create the bevels needed for a stave type construction using a tapered fence attached to a Veritas rabbet plane.

Originally Posted by DaveVman

Some pictures are worth 1000 words:

Jointer_DepthofCut_l.jpg3_Depth-Of-Cut-Handle.jpg

If you look carefully you will see the 'ruler' is not metric and because it is on an angle it is not standard spacing.
Probably an easy fix for a metal worker but I'm no metal worker.

So I thought to myself - I bet I'm not the first person to puzzle over this. I bet someone has a simple, cheap solution.

for me it's a "what's the issue?" sort of thing.
the ruler on a jointer is a gauge not a scale -- the distinction is that a gauge provides a relative measurement while scales provides an absolute value.

In three years of formal training I only once used the gauge on a jointer to achieve an absolute measurement and that was to taper a chair leg using a jig. In a production environment, I can see the value of being able to set an absolute value for a taper, but in a home shop by the time you've fiddled with a jig and different settings, you will have tapered all the components that need tapering as part of your set-up.
(in a production environment, the taper jig would normally have the correct gauge setting marked on it, meaning that the units on the gauge are just that -- units against which the pointer is set.)

Yes. I think you are right. All I need is to find a way to clearly mark a strip of metal.

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All I did with mine was to convert the measurements to metric, as the measurements are 1/64" apart and equals close enough to .4 mm, so everyone of those lines are .4 mm apart, 1/32" equals .8 mm 3/64" 1.2 mm and so forth.
Hope this helps.
Kryn

I just stick a straightedge on the outfeed table over the cutter head and use an engineers square to measure the height of cut. A snap check digital gauge ($40 from Timbecon) would be more precise and quicker.

Using a jointer as a substitute saw is something I wouldn't do. As a workaround in a pinch it's ok, but cutting bevels is such a normal thing I'd be treating it as a saw issue and fixing the saw first.