Official Luthiers Forum!

Tim, I built a version of Stew Mac's. I built it so I could dismantle it and up it in a drawer. I used parts I got off of eBay. The major difference between theirs and mine is the use of linear bearings. Smooth as silk and no slop.

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Aoibeann

PPPPIctures PPPPLease.

Edit, but please post in a new thread as this on is full of nonsense from that Padma guy.

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Ken

Come on James

why for you taken shots at me? What? you get some thrill out of stiring the pot....

However to accomodate your desire and need for titilation of witty comebacks I propose you all stop trying to derail Timcacca's thread and move this over to an new thread which me have just opened called...

The Official "Take your shot at the Padma" thread.

Here is the link http://www.luthiersforum.com/forum/viewtopic.php?f=10112&t=25197


blessings
the
Padma

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.

Audiences and dispensations on Thursdays ~ by appointment only.


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I got most of it from eBay, pretty much from one vendor too, 8020inc. The center post is 15 series. Do not get the lite stuff. The 10 series is too small. I'm sure one of the metric ones would work as well, but I didn't look into them.

The linear motion/bearing consists of two components, the U shaped aluminum piece and three bearings made of UHMW. You can put it together yourself
or you can pay them for a complete one.
Sorry, they don't seem to have a single unfinished bearing up right now.
Do yourself a favor and order it all at once, saves on shipping.

For the supports, I found three pieces of angle somewhere that I drilled four holes in each. I ended up using steel cross dowel bolts that just fit into the channel of the center post to bolt the supports to the center post. I used them with machine screws instead of ordering the the connects from 8020inc, mostly because I don't think about needing them at the time I was ordering stuff and couldn't see paying more in shipping for the item. The cross dowels work fine. I have no fear of them stripping out. I took the post with me to Ace Hardware and dug around until I found something that would work. I used T-nuts in the work board to have something substantial to screw the mounts to.

The aluminum angle that the router is mounted on came from Metals Online. They are local so I could just pick it up. Cutting the hole was a a serious pain. Ended up killing a cheap hole saw to do it. The UHMW doughnut came from John at Blues Creek. He was kind enough to make one up for me. I couldn't figure out how to fabricate it here with the tools I had and at that point I just wanted to get it done.

If you aren't comfortable working with metal, buy the jig from Stew Mac. It might hurt your wallet yes, but it beats a trip to the emergency room because you tired to make do with what you have to get something done.

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Aoibeann

Lillian, I saw a post about your binding machine somewhere a while back and really admired it, but could not find any of the components anywhere so I am really glad you posted on it again. Just a couple things, It looks like you have the guitar propped up high, is that because the router cannot go any lower for the cord? If so you could possibly cut the shaft down I suppose. What size machine screws did you use to anchor the bottom? Also I found these for angles which I suppose is what you were referring to what you forgot to order originally?
http://cgi.ebay.com/80-20-T-Slot-Alumin ... _937wt_794

Thanks

Edward, you are right. The way I mounted the router, the cord gets in the way. I was thinking I needed to be able look through the router base to see what was going on, so I mounted it with the opening towards the guitar. It became very clear as soon as it was built that all the action is under the mount. It doesn't matter how the router is turned. The next time I use it I'll mounted so the cord clears the post.

And yes the center post could be cut down and probably will be. I left it this way for two reasons, well three actually .
1) I didn't want to inadvertently cut it too short. I wanted to spend time with the design first. To see it there was a good reason not to cut it or a good reason to cut to a particular length.
2) Having the body up as high as it is exacerbates any error in the setup. Its easier to see an angular difference the farther out you take it.
3) I was tired of messing with it and wanted to get on with building the guitar.

The screws into the work board where the largest that I could find a T-nut for at the time. They are at least 3/8ths if not 1/2. Length was 3/4" if I remember correctly.

Yes, no. I had pieces of aluminum angle in the shop before hand that I had planned on using. But those should work. What I forgot to order was the funky bolts that fit inside the extruded channel.

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Aoibeann

Thanks for the info, I am thinking I will put together one of these for myself.
The item you linked though is to hold the anchor bolts at the bottom?

No, that is the standard bolt that is used in the channel.
This should be clearer.



I used these instead.


I put the machine screw through the two holes in the upper portion of the support brace and began to screw a cross dowel bolt on to each of them. Once they were on enough not to come off, I lined them up with the channel and slid them into place.
Just imagine these being the cross dowel bolt.

To mount the support to the board, I used a T-nut from below. You drill a hole the size of the outer portion that the bolt screws into all the way through the board and a then a larger hole (counter bore) from the backside so that it sits below the surface.

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Aoibeann

Edward, sorry I misread your post. Yes, they were for the mounting the post to the work board.

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Aoibeann

How do the factories do it? Benedetto uses a table mounted router with a rabbeting bit. Anyone else using a set-up like that?
Jason

Lillian, thanks again for all the info. I have pretty much everything earmarked and ready to order, but I am just wondering how good the bearing block slides in that channel, is there much resistance? Mostly all binding machines I have seen have had wheel bearings including the stewmac which is of a similar concept. Also, do you feel any need to counter weight the router upwards, or does it seem to work fine with all the weight resting on the guitar? I guess that rigid of yours looks pretty light, mine is a dewalt.

On the Taylor "Factory Friday" videos, you'll see them routing the binding rabbets with a fancy version of this type of jig.



When I took the Martin factory tour about 5 years ago they also used a similar looking concept.

This is my version, which despite it's simplicity works so well that I have resisted the temptation to build a more elaborate jig. I use a downcut spiral bit in the trimmer, so I get a very clean cut. And, contrary to most, I feed the instrument to the tool, and not the other way around (that's how the factories do it, too). The problem some people have with this type of jig is that it will make a deeper cut than it should if you tilt the instrument up and into the bit, so you have to make sure both bearings contact the sides at all times during the cutting. I guide the instrument by holding my hand on the bearings and the sides at the same time. I built this thing years ago, based on several similar designs I have seen on the web and in books. There are commercial versions available, but you can build one that works on the same principle from materials you most likely have in your shop for next to nothing, in a coupe of hours.

Here's how cleanly the downut spiral bit cuts

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Rian Gitar og Mandolin

Heath sort of beat me to this but there is no reason you can't use a binding fixture and manual binding cutter on a spanish heel construction. you just stop short of the neck heel and finish the inlet into the spanish heel by hand.

Something I will add for anyone building their own fixture is to set the center of the router to outer edge of the tower distance to be enough room to allow the neck area to clear the tower when doing cutaways. when I built my binding fixture (LMI or Rebecee Style) I found that the body interfered with the tower base when routing in the cutaway radius. This is not an issue with the Fleishmann/Williams style fixture because of the laterally articulating arm. But it can be an issue on a tower type fixture.

Thanks for all the replies, i plan on building some version, just not sure witch on yet. What's the donut for?

Since the angle the side makes with the top (and especially the bottom) is not exactly 90 degrees then if you allow the router base plate to lie directly on the top your binding channel will vary in width around the guitar. The donut provides a much smaller 'base plate' to contact the guitar top/bottom so that the variations in top and bottom angles don't change the width of the cut. Hope that makes sense.

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Steve Smith
"Music is what feelings sound like"

The linear bearings are somewhat adjustable. You can mount them to be loose with in the channel or give set them up to have serious resistance. I have mine set up so that there is no slop, but not so that they are tight and difficult to move.

When I first started thinking I could build my own binding jig, I had stumbled across the extruded aluminum on eBay while looking for something else. I found the center post and thought that the bearing setup wouldn't be to difficult to replicate. At the time, someone had posted about the slop he found with his new Stew Mac binding jig. He found a solution and discussed it with Stew Mac. If I remember correctly, they implemented his changes in their design. After chewing on the issues he talked about and trying to get my head around to fabricate it to tolerance, I felt that it was easier to use a bearing designed for use with the extruded aluminum. As far as I could see, using a linear bearing simplified things.

I don't think a counter weight is necessary. You can't see it, but there is a machine screw/cross dowel setup for a stop to make sure that the router didn't bottom out. You have to pay attention to what you are doing of course, but its not like I was wrestling with it to keep in contact with the body.

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Aoibeann