Miter sled - I don't get it

saminmn · Post by **saminmn** » Sun Sep 22, 2013 9:16 pm

I recently made a miter sled, but found that the fences were not at exactly 90 degrees. It was a simple design, but once the fences are screw 'n glued in place there is no adjustment. So the current issue of Woodsmith magazine (#209) has a miter sled on the cover and I thought "This is one I can make" as it had used a solid block of wood for the fence. I can cut a right angle corner that would do the job. I would loose the ability to clamp a stop block, but this is so simple I cannot mess it up.

So I started reading the article and they went and made it something that needs reliable 45 degree angles being attached to the sled base. It is not that the fence faces need to be smooth, because they add sand paper to them. Why make it (for me:rolleyes:

) hard?? Why?

I am going to make the sled, but without the pretty mitered look on the point of the fences.

Gene Howe · Post by **Gene Howe** » Mon Sep 23, 2013 7:51 am

Sam,
The 45' at the point will provide support all the way to the cut. 90s will not.
A plastic 45 angle found at a good office supply will work to set your fences.
A rough surface might transmit through the sandpaper. Planing them would be best.

dusty · Post by **dusty** » Mon Sep 23, 2013 8:06 am

saminmn wrote:I recently made a miter sled, but found that the fences were not at exactly 90 degrees. It was a simple design, but once the fences are screw 'n glued in place there is no adjustment. So the current issue of Woodsmith magazine (#209) has a miter sled on the cover and I thought "This is one I can make" as it had used a solid block of wood for the fence. I can cut a right angle corner that would do the job. I would loose the ability to clamp a stop block, but this is so simple I cannot mess it up.

So I started reading the article and they went and made it something that needs reliable 45 degree angles being attached to the sled base. It is not that the fence faces need to be smooth, because they add sand paper to them. Why make it (for me:rolleyes: ) hard?? Why?

I am going to make the sled, but without the pretty mitered look on the point of the fences.

I assume that this sled is going to be used on your Shopsmith. If so, you do not want a sled with a "permanently" attached fence.

The sled, by its' design, is positioned on the main table by its' miter bar(s). While the miter tracks are in the main table and the main table is adjustable (with respect to the blade), you do not want this to be your final adjustment. Unless you believe that you can precisely align the table to the blade, I believe you are going to want to tweek the fence.

[ATTACH]22845[/ATTACH]

I don't know just how accurate this sliding table fence is but it does the job for me. Yes, those a draftsman's triangle are my primary alignment tools for the sliding table.

JPG · Post by **JPG** » Mon Sep 23, 2013 11:32 am

Not having seen the plans, I be making two assumptions.

The 90° 'fence' is as illustrated in Dusty's pix above.

A 45° 'fence' is added to allow cutting frame miters.

The 90° 'fence' absolutely needs to be adjustable(initially and possibly in the future).

The 45° 'fence' only has one 'critical angle at the 'point' which must be = to the angle desired for the frame 'corners'(typically 90° for rectangular frames). If that 'point' is slightly off relative to the blade, the two sides of the fence are 'complimentary' and will still add up to the desired corner angle. If the 45° fence is made from a single triangular shaped piece with the 90° point it could be easily made from a square piece cut accurately cutting the diagonal between opposing corners(ala Shipwright) . An inaccuracy of the two base angles will be realized in unequal sides of the two pieces(blade skew angle at the point[again]) but likely will be too small to be objectionable.

The 'fence' faces do need to be Flat. Adding sandpaper to a flat face would not introduce much error, and the non-slip feature would be the greater factor (IMHO).

Obviously perfect angles would be 'best'.

I apologize if my two assumptions are invalid, but this the way I 'see' it:).

saminmn · Post by **saminmn** » Mon Sep 23, 2013 1:43 pm

Here is a link to the Woodsmith #209's TOC with a pic of the cover.

Sorry for any confusion. The miter sled shown is for cutting small parts, but with that approach it should be easy to ensure a 90 degree total angle.

But then they made the sleds fences from 2 mitered boards instead of a single cross cut.

JPG · Post by **JPG** » Mon Sep 23, 2013 3:14 pm

saminmn wrote:Here is a link to the Woodsmith #209's TOC with a pic of the cover.

Sorry for any confusion. The miter sled shown is for cutting small parts, but with that approach it should be easy to ensure a 90 degree total angle.

But then they made the sleds fences from 2 mitered boards instead of a single cross cut.

So who said 'they' were 'experts'?

Gluing the 90 fence was a clue to their degree of expertise.

Ditto the 45!;)

They need Paul M to straighten them out!:rolleyes: