Over-Arm Router Fence

[DLB]

At one time Shopsmith produced several variations of Over-Arm Router (OAR) aka Overhead Pin Router (OPR) Systems, both standalone and Mark mounted. The later standalones, like mine, include under table routing. These included tables of various quality and split fence brackets, basically a pair of extruded aluminum angle brackets I believe intended for shop built fences.(?) I'm considering replacing my aged laminated MDF or particleboard table with a 21st century phenolic router table that's designed, of course, for under table routing. I could conceivably replicate the array of screw holes from the SS version that support the angle bracket fence system, but I don't really care for that fence anyway. My table also has a JessEm fence for under table work, but it doesn't really work for overhead router use.

My question: Does anyone have an overhead router fence that they really like, can be for either Mark-mounted or stand-alone. (I think.) I'm open to purchased, modified from something, or shop made.

- David

[RFGuy]

David,

Did you see this past thread from Dennis on his OAR setup? It looks like a Jessem fence on it, but you are saying it doesn't work for overhead use? Perhaps Dennis or others have more thoughts to help.

viewtopic.php?p=213728#p213728

[BuckeyeDennis]

I can recall using the overarm router for only a few use cases: pin routing, countersinking/counterboring, and milling stopped slots. For pin routing, of course, you don’t need a fence at all.

The SS overarm router is positively brilliant for milling stopped slots. I kinda feel sorry for all the YouTubers when they have to drop a workpiece down onto a spinning undertable router bit.

For these use cases, you don’t need a fancy fence, and the height of the Jessem fence renders it all but unusable with the OPR in any case. So I’ve been dragging out the original SS fence angle brackets when the need arises, and using a straightedge to align them. This works ok, but is more bother than it needs to be.

Fast forward to a few months ago, and I needed the ability to offset my Jessem undertable router fence very precisely for successive cuts, to within a very few thousandths of an inch. For that, I wound up 3D printing some T-nuts that fit in the Jessem mounting tracks (on each side of the OPR table). I’d mount stops to the Jessem track using those T-nuts, slide the stops up against the back of the fence, and lock them down. Then when I needed to offset the fence, I’d unlock the fence, drop precision pin gauges between the fence and the stop, and then lock the fence down against tbe pin gauge. That worked like a charm.

So now that you made me think about it, I think a very satisfactory low-profile adjustable fence could easily be made by simply mounting a board with a nice straight edge between the two Jessem mounting tracks.

[DLB]

Did you see this past thread from Dennis on his OAR setup? It looks like a Jessem fence on it, but you are saying it doesn't work for overhead use? Perhaps Dennis or others have more thoughts to help.

viewtopic.php?p=213728#p213728

Yes, in fact I have the same JessEm fence inspired by Dennis. Some users don't use a fence for overhead routing, and I get that. I have an overhead router bias. My first 'router table' was an overhead setup B&D sold for their Workmate line. I later adapted it to the extension table on my Greenie, creating an overhead router for the main table. So I have decades on overhead routers Vs. hours on the more common variety. The Jessem fence is predominantly an "L" extrusion with a hole in the bottom and opening in the fence so an undertable router spindle and bit are 'buried' in the fence and dust plenum. The B&D contraption is a rectangular tubing extrusion with a hole in the top, allowing the same thing but for an overhead setup.

Shopsmith once made a fence that appears to be compatible with both under and over table routing. Only one I've ever seen is owned by another forum member and is in this thread: viewtopic.php?p=299863#p299863 The catch is that it is specifically compatible with the 520 table system, but I presume that would be easy to overcome. Procurement is seriously problematic. If I could buy 10 feet of that extrusion I could find uses for it.

- David

[JPG]

Y'll remember this?

viewtopic.php?p=282820&hilit=router#p282820

I am replacing the t-nuts with threaded bushings so the fence mounting bolts will store below the top surface.

[RFGuy]

Shopsmith once made a fence that appears to be compatible with both under and over table routing. Only one I've ever seen is owned by another forum member and is in this thread: viewtopic.php?p=299863#p299863 The catch is that it is specifically compatible with the 520 table system, but I presume that would be easy to overcome. Procurement is seriously problematic. If I could buy 10 feet of that extrusion I could find uses for it.

- David

David,

Yeah, I have seen that Shopsmith fence (520 mounted router fence - top pic in thread you linked) in a video from the guy that used to sell the PP alternative. I think his videos got taken down after the Shopsmith litigation so I can't see them anymore to compare. He had one of those Shopsmith router fences that you show. I always had assumed that Shopsmith fence was a ripoff/knockoff of the Incra Wonder Fence, or if not then it must be purchased from them and resold by Shopsmith for a brief time. The extrusions look the same to me. The only difference, besides annodized color, between the Shopsmith one and the Incra Wonder Fence is the Shopsmith one has a 45° mitered opening whereas the Incra Wonder Fence is squared off. IF you want a solid fence, but of the same kind of extrusion as this, I would recommend contacting Incra directly. Their engineers are very helpful. The head engineer there I believe is Mark Mueller and he has been very helpful for me when I was considering some LS Positioner options to mount on my 520 table system. Let him know what you are trying to do and what products you might be interested in. I have received custom orders from them, e.g. for their special T track that they use on their router tables that they sell. I got a custom length of this extrusion, for my custom MFT router table, from them and it was reasonable in price. IF it is one of their products, or a variation on one of them, they are very helpful to get you what you need. Highly recommend them in this regard. Good luck!

[DLB]

Thanks guys, some good inspiration here. I have a pair of Uni-T-Fence sections from Peachtree (https://www.ptreeusa.com/rtr_router_fences.htm) that I'm not using. These can form the basis of a good solid fence that's compatible with the OAR and my table, but I haven't worked out how I'd get quality dust collection with them. Those Wonder Fence sections would likely be a better choice because they support dust collection through the section, which is why I mentioned that rare SS fence.

- David