Shop Built Pin/Overarm Router...seeking thoughts

[Stephen Edwards]

Years ago I made a quick, nothing fancy pin router for one piece that I was working on. Now, I'm ready to build it RIGHT to use frequently in the shop. I'm seeking thoughts, ideas, suggestions, etc, from anyone who's ever built one of these tools or has given thought to doing so.

Here's the basics. I have a 1960's era Craftsman RAS, minus the saw. I have completely restored the vertical support, the arm and the carriage from which the saw hung. In my original one that I made years ago I simply made a box that mounted to the plate (carriage) that slides horizontally underneath the arm. A router was mounted into that box. It worked perfectly for that one job.

This time around I want to rig it a bit differently. I'll be hanging the fixed base of a Bosch 1617EVSPK from the carriage. I can get one of those fixed bases cheap from the auction site. They're always on there. What I'm considering doing, and here's where your thoughts and suggestions may prove to be helpful, is to take the fixed base to a machine shop and have them cut off the bottom portion of the base. I want to leave enough of the base to hold the router and have the raising and lowering mechanism still be functional. In other words, I want to be able to fine tune it more than just with the lift of the RAS. But, I don't want the bottom of the base to be in my way. I'll figure out someway to hook up some DC.

The question is: What are some thoughts for building a device to hang the fixed base from the carriage. I would like to have built in adjustments on this device so that I can make sure that the router bits are perfectly 90 degrees to the table underneath.

Any thoughts or suggestions would be greatly appreciated. Perhaps someone has already done this before, in which case no need to reinvent the wheel!

Thanks!

[Chris Padilla]

Stephen,

Do you have any pics of what you've got now?

[Dave Verstraete]

Stephen
As chris said ..Pics would be helpful. I have one of those bases and will take a look. I could also help with some of the metalworking if you come up with a plan. I own a small metalworking company and have mills and grinders available to me.

[Stephen Edwards]

104570

Thanks for the replies fellas, I 'preciatte it. As you can see, here's what's left of the old RAS after I cleaned it up earlier this year. The wooden box that I used years ago that was bolted to the metal plate that rolls along the carriage is history, long gone. Even though that worked for the one particular project that I built it for, I want to build this thing differently this time...more versatile and more accurate. Since I started coming to the Creek, I've learned that lots of things CAN be done! My skills and my knowledge have grown in leaps and bounds from reading threads and posts here, and from contacts that I've made through SMC. I can only say Thank You to so many of you who willingly share your knowledge.

In my prior post in the beginning of this thread I explained that I want to hang the fixed base of a Bosch 1617EVSPK from that plate that rolls along the carriage. As Paul Harvey would say....here's the rest of the story!

I'm going to build a router station 60-72 inches in length. As you're facing the table, the right end of it will be a conventional router table setup. The left end of the table will be the pin router. When the pinrouter is not in use the arm swings to the right, over the table and out of the way, against the wall.

A miter track will run the entire length of the table, just like in a conventional table. Two sets of T-Tracks will be installed in the table to accomodate two fences, one for the undertable router and some kind of fence for the pin router whatchacall it in case I ever wanted to use that with a thin fence for various tasks that would be suitable (and safe!) for it.

Though this picture doesn't show it, the bottom of the white painted housing around the round steel shaft that goes up and down, is a flat steel plate. In the center of that plate is a round hole through which protrudes the bolt end of the threaded rod which makes the arm go up and down. I THINK that I want to completely remove the green painted supports that once supported the table for a RAS and mount the vertical shaft directly to the table top (posssibly reinforced with steel in the table top where that mounts.) There's enough room on the bottom of the steel plate to drill 4 holes to bolt the whole mess to the table top. I realize that I'd have to make a recess for the bolt that protrudes through that plate so that it would indeed mount firmly and flat to the reinforced portion of the table top where it would be mounted. My reasoning for that is this:

A 1 1/2 inch thick table top mounted on top of the existing green steel table supports gives the following clearances from the top of the table to the bottom of the metal plate that rides on the carriage:

Arm fully in the up position:clearance =16"
Arm fully in the down position:clearance =9"

IF.....I remove the green painted steel table supports and mount the vertical shaft directly to the table top I would then have the following clearances from the top of the table to the bottom of the metal plate that rides on the carriage:

Arm fully in the up position:clearance =20 3/4"
Arm fully in the down position:clearance =13 3/4"

Option number 2 significantly increases the clearances and the options.

Speaking of options and now that I'm on a roll, here's another possibility for your consideration and suggestions:

This fixture that will hold the router base to the rolling plate (what's left of the base when we get through "fixin" it!) would be be very cool if it could rotate backwards 90 degrees so that the bit would then be parallel with the table top. Then, with an auxillary table and fence that attaches to the main router table, we could have a "horizontal router" set up.

Thanks for your patience in reading my explaination. I know it's a bit wordy but I don't know how else to explain it. I KNOW that this can be done. I just don't know how to design or make the "missing link", the part that hold the fixed base of the router to the plate that slides along the carriage. Any and all thoughts are welcomed and appreciated, with the exception of suggestions that "It can't be done!". I know that there's enough brains and collective experience here at SMC to help me work this out.

Again, thanks for your help.

Merry Christmas and Happy Holidays to ALL!

[Rick Potter]

I believe Shopsmith made an overarm setup years ago. It looked a lot like what you have now. Perhaps if you looked at the Shopsmith site, there may be pics of that unit and modifications owners have made.

Rick Potter

[Stephen Edwards]

I believe Shopsmith made an overarm setup years ago. It looked a lot like what you have now. Perhaps if you looked at the Shopsmith site, there may be pics of that unit and modifications owners have made.

Rick Potter

Thanks for the suggestion Rick. I'll see what I can find on their site. I worked on the concept of the bracket some this morning while my mind was clear (rare moment!).

[Sonny Edmonds]

Even at this point I'm still not sure of what you want from your design.
But maybe you can glean some info from this Popular Mechanics Article (http://www.popularmechanics.com/home_journal/workshop/1274466.html).
It looks to be an interesting project, no dought.
I love challenging shop projects like this. Getting it done is often more fun and brain stimulating than what can be done with it.
Dust collection will work out later. But getting the pin router done and working will be the fun part.
Take a look at the PM sites article and see if it brings some refined ideas to what you have going on already.
Do you still have the trolley that carried the saw works? Or will you be starting at the track for the trolley and working out from there? :)

[David DeCristoforo]

The one thing I would worry about is the lack of any plunge capability. Most (if not all) "pin" routers whether overhead or "inverted" have an air powered elevation system to bring the bit up (or down) into the work. This is one of the best features on these machines. I have an old Delta overhead router and it would not be nearly so useful without this feature.

[Will Blick]

This may have been answered before....but what is the advantage of an overhead pin router, vs. a table top pin router....both use templates, both can use same size bits, ...

the advantage is escaping me.... help anyone?

[Dave Verstraete]

Stephen
Here are a couple of pics of the Shopsmith pin router. The arm on the right is the plunge arm connected to a rack gear.

[Dave Lehnert]

Stephen
Here are a couple of pics of the Shopsmith pin router. The arm on the right is the plunge arm connected to a rack gear.

The new Shopsmith pin router hooks up to the Mark V. Here is a video on the use of a pin router for anyone interested.

http://www.shopsmithacademy.com/SS_Archives/SS107/SS107_Overarm_Router_4.htm

Here is another link with all kinds of info and a group of videos.

http://www.shopsmith.com/ownersite/catalog/rm_overarmpinrouter.htm

http://www.shopsmith.com/ownersite/catalog/images/RouterArm_static.jpg

[David DeCristoforo]

"...what is the advantage of an overhead pin router, vs. a table top..."

For me, the overhead has one (BIG) advantage. Since the stock is between the table and the bit, the thickness of the remaining material remains constant regardless of any variations in the thickness of the stock. Imaging milling grooves in plywood cabinet ends for rabbet and groove joints. If you set the bit depth to leave 3/8" of material at the bottom of the groove, your cabinet boxes will always come out the correct length. If the bit is under the stock and the stock thickness varies by a sixteenth of an inch (as is common with plywood) the variation will show up in the remaining thickness at the bottom of the groove. Result...up to one eighth inch variation in net cabinet length. Now imagine a run of frameless cabinets made up of two foot modules, across a fourteen foot room. Total potential error of seven eights of an inch! Just one example....

[Ed Kilburn]

I have an homemade over arm router for sale see post; http://www.sawmillcreek.org/showthread.php?t=86548

[Mike Heidrick]

Ed, does yours have a pin assembly as well?

[Greg Coleman]

Here's the basics. I have a 1960's era Craftsman RAS, minus the saw. I have completely restored the vertical support, the arm and the carriage from which the saw hung. In my original one that I made years ago I simply made a box that mounted to the plate (carriage) that slides horizontally underneath the arm. A router was mounted into that box. It worked perfectly for that one job.
[/quote]
Do you ever visit the Wood Magazine forms? There is a guy there that used an old Craftsman RAS to do about the same as you intend. He included a couple of motors and gears and a switch actuated by his knee to raise and lower the router. The whole machine is pretty neat. I believe he could give you some great ideas.

[Will Blick]

Dave, that is a great example of the benefits of overhead vs. below the table.... I recall a few other advantages in another thread awhile back, but my brain can't retrieve it...

[Stephen Edwards]

Thank you all for your comments, helpful suggestions and the links. They're very helpful!

Sonny: Yes, I still have the trolly with wheels that rides along the carriage of the arm and can be locked into any position on the arm. You're right,

"Getting it done is often more fun and brain stimulating than what can be done with it. Dust collection will work out later. But getting the pin router done and working will be the fun part."

Thanks for the link to the PM website showing their version of a pin router.

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David DeCristoforo: "The one thing I would worry about is the lack of any plunge capability."

I hadn't even considered building this thing with plunge capability. Now, my head is really gonna hurt working out a solution for that! Excellent suggestion and thanks for bringing it to my attention.

Also, the consistent amount of remaining material between the bottom of the cut and the back of the work piece, or intentional lack thereof in some cases, is important for my main intended purpose of wanting to build this contraption. The photo below will explain what I mean.

104772

The above photo shows the piece for which I made my primitive version of the pin router. However, When I made the prototype of this piece of art back in the 80's I didn't have enough sense to consider to make the groves wider and deeper near the bottom of the piece, thus creating the illusion of a diminishing point as your eye moves upward to the top of the "hills". As an after thought I attempted to do this with a dremel tool and the result is less than satisfactory to me because the "furrows", as it were, in the fields aren't clean looking cuts. I think that I can solve that problem by simply positioning some shims on the bottom side of the pattern so that as the pattern moves along the table the cuts at the bottom of each groove will be deeper and wider, creating the desired illusion. Now, I want to build a numbered edition series of this piece, using different species. And, I want clean cuts on all the groves.

Here's another piece that I want to do a series of. On this first one I cut individual pieces with the BS. Seems to me that it would be much easier to use the pin router for this piece, too.

83906

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Dave L and Dave V..........Thank you both for the photos and links to the ShopSmith version of a pin router. One of the videos that I saw on the ShopSmith site even showed the set up for a horizontal router on their pin router!
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In my mind, what's left of it, the main advantage of using the old RAS for the support mechanism of the pin router contraption is that I can have a BIG table underneath it with plenty of room between the router itself and the vertical support of the arm thus increasing the capacity of the size of pieces that I run through it. Now, I just have to figure out how to build the contraption to hang the router from the "trolley" (Thanks Sonny, for that word!), be able to turn it backwards 90 degrees......and possibly include a plunge mechanism of some sort.

Perhaps when John Nixon's (Eagle Lake Woodworking) Motorized Router Lift is on the market, hopefully soon!, one of those could be worked into the pin router design for the plunge capacity. I am for sure going to put one of those on the under table router end of this new router station.

Thanks again to everyone for all your suggestions and helpful thoughts, links, etc. Please keep 'em coming if you have more suggestions or ideas to offer! I keep doodling on paper to come up with the mechanism to actually hold the router that will hang from the trolley.

[Ed Kilburn]

Yes it has a pin that is mounted in the table. I have a production job that I run from time to time, and had the patterns CNC cut from aluminum. To keep the pin from galling or wearing the pattern I used a 1/2" bearing on my pin. At last spring Grizzly tent, I was able to pick up a 5Hp over arm router at a very good price:D. I now have the homemade one for sale, if it doesn’t sell till I get around to building a horizontal router, I'll strip it for the bearings and other parts. You can check out a video of the pin router in action on Utube. http://www.youtube.com/watch?v=MV4KJRg56Pw:) (http://www.youtube.com/watch?v=MV4KJRg56Pw)

[Stephen Edwards]

The one thing I would worry about is the lack of any plunge capability. Most (if not all) "pin" routers whether overhead or "inverted" have an air powered elevation system to bring the bit up (or down) into the work. This is one of the best features on these machines. I have an old Delta overhead router and it would not be nearly so useful without this feature.

David, what's the difference between overhead and inverted, please?

[David DeCristoforo]

"...what's the difference between overhead and inverted, please?..."

Overhead: The bit is above the table and the pin is in the table.

Inverted: The bit protrudes through the table from below (like a "typical" router table) and the pin is mounted above.

They are commonly to referred to as either an "overhead router" or an "inverted pin router" although both are technically "pin routers"

[John Grounds]

The question is: What are some thoughts for building a device to hang the fixed base from the carriage.


One option would be to attach the router via a pin and fix the work with an index type arrangement.

Something like this:

104860

104861

104862

The best to all in 2009 and beyond.
John