Official Luthiers Forum!

When my son and I took our class from Kevin Gallagher/Omega Guitars, we used a Hitachi TR6 (I think), which is a laminate trimmer with a tilting base. This worked GREAT for cutting the binding steps and compensating for the various angles on the back of the guitar. The Hitachi is no longer available and I've found these two items:

1) Porter-Cable 7319
http://www.deltaportercable.com/Product ... ctID=11108
I have found it for just under $140

2) DeWalt D26670
http://www.dewalt.com/us/products/tool_ ... ctID=15678
This unit requires the purchase of their adjustable base:
http://www.absolutehome.com/home/1/8191 ... 26672.html
Together these items would run just over $140.

So - have any of you used these products - and since I'm not up on my tool brands, is one of these considered better than the other?

Thanks!

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P A U L B U R N E R
Burner Guitars

Kinda wierd how when i got a question about something, others seem to ask similar questions.

I had a rigid trimmer that i got for christmas, and i would not recommend it. maybe i got a lemon or something, but it started sparking and fizzling it out. i still got it and might try to get someone to fix it, but I just decided to start lookin for a new one.

I think both trimmers you sited are decent options. I would probably prefer the dewalt, as i have just always had good luck with dewalt tools.

I was wondering also if you could tell us what kevin used as a guide for using the hitachi trimmer to route binding channels. did kevin have a williams jig, or did he do it freehand with a guide attachment?

The problem is for me because the dome shape is a consistent spherical radius and the guitar body intersects this sphere at various dimensions from the center axis minor changes in pitch happen. The smaller the foot-print of intersection of the base to the back or top the less the influence of the minor pitch changes. The more of the base in contact the greater the influence. This is very evident when turning tight radius body curves like cutaways and tight waists. The great amount of base contact is will lead to inconsistent dept or bit angle. That is why most fixtures and jigs have a donut or very small base contact and use some form of indexing the rim to maintain bit angle and just touch out on a very limited and very close to the cut area to set depth.

Here is an exaggerated example of what I am saying. An arc intersected by two different cord lengths and the change in pitch angle caused. This is an exaggerated example to make it easy to see. On a real guitar the change in pitch angle change is about 2 degrees on a dread from waist to LB with a 15' back radius 88.73 degrees at LB and 90.72 at the waist and every point in between is a variable between these two pitch angles.



So you see you would have to be constantly changing the angle for the full base contact to work well

So, are than any tutorials or suggestions about making a proper donut? What is it usually made of?

UHMW or phenolic resin it is jsut a ring about 1/8-1/4" wide foot-pring. inside edge clear the bit by about 1/4"-3/8" Check with John Hall I belive he sells replacements for his binding fixtures.

I could use one of them donuts myself...

Or, if anyone has come up with an alternative (ideally suited to the Bosch Colt) please let me know.

by the way neither the PC or the Dewalt tilt unless you by a tilt base attachment like the third link. but you still have the ever changing pitch angle to deal with. Would work great on a pure round body. not so great on a typical guitar shape.

MichaelP,

The Porter-Cable 7319 comes with the tilt base.

I understand your drawings and appreciate your comments - but I'll stick with my personal experience of how well it (tilting base laminate trimmer) worked for me.

I did make 3 changes to the base while cutting the binding channel as the angles changed.

Just wanted to know if DeWalt or Porter is a better build unit.

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P A U L B U R N E R
Burner Guitars

I currently use that Porter Cable tilt base for routing binding on the back. The best you can do is to average out the angles and go for it. As Michael says, the angle and depth is always changing. I have learned to deal with it, but am in the process of changing my binding routing method.

The PC router is a good router, but I don't like the tilt base. It is difficult to adjust the heighth accurately. You loosed the screw, slide it up or down, then tighten the screw. There is no fine adjustment. I wouldn't recommend going this direction.

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John Ressler

Before I bought my Luthiers tool binding jig I use some kniting donuts I found at Walmart made of UHMW. I glued in place on my base with fish glue so I could seperate off later with steam. I had to stack 3 to gain the height needed so the base cleared the rise of the dome all the way around the body. but they did the trick for several months.

Don't Rigid Trimmers have a Lifetime Warranty, like the other Rigid tools?

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

In some packages these routers may very well come with the tilt base but I own both and neithier came with the tilt base in the pakage I bought. But that is neither here nor there. The Dewalt base gets hot to the touch, the PC wont. Both are a tad dificult to micro adjust height.

I certainly was not suggesting that you must follow my thought pattern I was only explaining the cause and effect of the geometry.

Sigh... I used one of these to cut binding channels when I was taking Frank Finnochio's class, and have been looking for one ever since.
I'd buy every one I could find, if I could find one.

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Jim Kirby
kirby@udel.edu

I have the Hitachi M6SB, which I believe was the trimmer that replaced the TR6. It does have a tilting base, but the adjustments are pretty crude. I agree that cutting a nice, even binding rabbet on the back is difficult with this type of base anyways, so I wouldn't look for a trimmer with a tilting base for that purpose. The trimmer is nice though, but I personally prefer the PC 310 and Bosch Colt.

I would suggest you build a binding jig of some sort, no matter what type of trimmer you decide to buy. You should find examples of several types if you look in the archives here. The doughnut that lifts the base off the top and back can be a simple steel washer glued to the bottom of your trimmer base, btw. Here's a picture of my setup:

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Rian Gitar og Mandolin

Ok - I'm such a newbie I don't know what a donut is - other than the edible kind.

Someone show me a photo and teach me.

I've gotten lost in my own thread!

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P A U L B U R N E R
Burner Guitars

i dunno waddy but i am calling them,

Guys,
The geometry is a given with the radius of the back being varied by the bracing and the taper, but it's
certainly not an issue that can't be overcome sufficiently with the right trimmer and the right adjustability.

For classes, we always use the TR6 laminate trimmers to give the students an idea of how they can
achieve great binding ledges without having to invest time, money or both in a binding jig or fixture
right away.

By making a few adjustments to the angle of the base to match an angle gauge that takes a reading off
of sections of the back's perimeter, great results can be gotten with no thin areas or gaps between the
bindings, back or sides.

I'd put the binding job we did on Paul and Kyle's guitars using the TR6 against any that I've seen on guitars
from a lot of the finest builders in the world and would have to say that it is better than many. Variations of
a few thousandths of an inch as the cuts meet and overlap are easily smoothed and blended using a file.

I use a binding fixture when I do my guitars most times , but still like to use the trimmer to cut ledges occasionally.
Partly because I can cut them with my eyes closed after a couple of hundred guitars done using it. I waited
much longer than I needed to to switch to the binding jig just because I enjoyed having more contact with
the work and actually making it happen rather than saving the time and leaving it to the jig.

I'm the same way with my bending. I have two great Fox bending machines, but have only bent a single set
of sides on them. I missed the interaction with the wood that I enjoy so much while hand bending and the
benders went on a shelf, the blankets and stats went into a box and have been there ever since. Almost 500
guitars and I can still tell you the serial number, model, woods and owner of that one guitar that got the
sides that were bent on the Fox bender. It's old school, but until I have to change again, I'm going to enjoy
doing it.

On another note, I can bend a pair of sides in less time than the bender took anyway.

Everything doesn't have to be automated, jigged and fixtured and tooled up to be done the right way. The
result is what's most important while the path to reaching it in this industry should be a enjoyable to the
individual as possible. We are truly blessed to be able to do such an incredibly fun thing for a living and the
fact that we can each have our own ways to getting it done males it an even more enjoyable thing.

Regards,
Kevin Gallagher/Omega Guitars

Micheal,
i was going to buy a bosh colt and one of the luthiur tool router bases.
is this what you have and if so do you recomend it?

i have trouble with binding and i allways have trouble on the back at the top of the upper bout.
the only way to avoud this is with true channel jigs but my time is presouse and i dont have time to make one.

i am hoping the luthier tool base will help me with this and give me better results than my dremmal.

Joel.

well said kevin,

In the college where i learned (merton college in london) the first year guitar makers have to everything except the truss rod channel with hand tools.
this teaches them the hand skills and the patience that is needed to biuld a guitar.

becouse of this i use mainly hand tools and love to bend my sides by hand even though i have a heat blanket.

sometimes it takes longer to set up jigs etc than it does to job buy hand.
for example i can cut my end graft slots in 5-10 mins by hand and it would take me this long to set up a jig

i suppose evry one has there own methods but i love using hand tools where i can.

that said cutting binding ledges by hand is tediouse ,time consuming and to be honest a little messy unless your very good so this is one job where i am glad to have power tools and any jigs that make the job easier.

i think every one has one job they are just crap at and mine i am afraid is binding

Joel.

Joel,
Agreed my friend. Binding is not one of my favorite tasks either. I can rip the steps for bonding and purfling
on the top and back of a guitar in about a quarter of the time using my binding jig that it takes to do it with
the trimmer, but there are just some days that I am in the mood to put my hands to it and go the old route.

It's just an occasional preference of mine.

When a guitar has a cutaway or is a more curvy body shape that presents more of the back to side intersection
variation that occurs, I always use the jig, but a dread, OM or other shape with more gentle curves, I like to wax
old school on it.

I did a dozen guitars in the beginning of my career with an old fashioned purfling cutter. It was real chore and
could get pretty messy if you weren't exceptionally careful, but all came out great and are still in the hands of
their original owners. Those guys loved the fact that I used all hand tools on their guitars.

Charming to see? Yes Attractive to do? Not at all.

Regards,
Kevin Gallagher/Omega Guitars

I do now use one of the Williams jigs, with a DeWalt trimmer and its guide follower and a downcut bit, but before that I used a tilting base trimmer as Kevin says, I used the Makita 3708. I do though still get great pleasure, on my hand tool only builds, by using a gramil and chisel. By the time I get the Williams jig out and set up, got the bit in the trimmer, adjusted the depth and width of cut, it's probably just as quick to do it with a gramil and chisel.

Like learning to bend on a pipe first, I would like to think that every aspiring guitar builder would have ago at cutting channels by hand.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Kevin - are you saying you change the angle of the tilt base several times as you go around the guitar, or do you find one angle as a happy medium to use around the entire guitar?

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John Ressler

John, when I was in the class with Kevin and we used the tilting base lam trimmer, I changed the angle 3 times when cutting the channel for the back. This was based on testing the curve with a tool and finding that the angle was very consistent from about 4 O'clock to 8 O'clock as we traveled around the lower bout of the guitar. Things changed again in the waist section and one more time at the upper bout. These were small adjustments and weren't very time consuming, but were obviously needed (based on our angle tool check).

Maybe someday I will have a Williams jig or something like it, but I'm about to tackle my first "solo" project, and think I'll probably go with the lam trimmer as we did in the class. I'm familiar with the technique and don't really want to introduce a new learning curve into a build that is already going to test my abilities. (grin)

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P A U L B U R N E R
Burner Guitars

Once you figure out that the key to using the Luthierstool base is that you hold and guide with the bearing assembly and not the router they work great. When I bought mine they only offered them to fit pc310 or Dewalt I first bought a base to fit my Dewalt. But the center of gravity on the Dewalt is to high and it always wanted to tilt towards the body. This does not damage anything but means you need to be vigilant about keeping the bearings in contact with the sides. I bought a second for my PC 310 much lower center of gravity and worked much better. I love mine, some hate them. I think the key is learning how to hold the rig and how you keep the guitar from moving around. Most use a rubber router pad and seem to have issues with the guitar rocking and moving. I use V-clamp vacuum clamp and that eliminates the guitar from moving at all. I also find it easier to use at or close to eye level than down at waist level so I have my vacuum clamp on a pedestal that is just below eye level.

You must understand that the key is to keep the bearings always in contact with the sides. Do that and it work great. The one flaw it may have is it could be balanced a bit better. A tad more weight in the handle of the bearing assembly would make it a great tool.

One more thing to understand is that only about a ¼” of the base rest on the guitar ant any time. The angled base plate is angled to clear any interference the dome will present and stop the base from allowing the bit cut deeply into the top or back if the router tilts inward. The full base is not intended to ride on the top or back

I agree with Kevin. A tilt base works fine for cutting the binding channels. I set up the base to find a happy medium between the butt of the guitar and the neck end of the guitar. The neck end usually need a bit more tilt. I cut the channels and then use a file to true up the channel. This takes little time at all.
I also prefer the PC trimmer to the Dewalt. The Dewalt design is a bit of a pain to adjust in my opinion.
I also use the Lutheirstool base and feel comfortable with it. As Michael said, it takes a bit of getting used to. The trick is to keep the bearings against the side of the guitar. Some of my students find this method a little intimidating.