My router's over ten years old and I already replaced the bearings once. I don't think the warranty is an issue.
Actually being able to use the router, provided it's solidly mounted, seems
like an attractive option. Maybe not the best one from a rigidity standpoint,
but probably acceptable.
What I need to do is pretty simple. I've got to mill a flat surface on the
top of a guitar body. The surface to be milled is at an angle with relation
to the back. This is easily achieved by simply clamping up the body with
a suitable block under one end to set the angle.
For the moment, I'm just going to use polished, sharp, high rake square inserts made for finishing aluminum in my 3" face mill, and run it at max RPM. Depth of cut won't be much.
I've found that cutters made for cutting aluminum generally give good results
in wood as well.
In fact, I don't buy router bits anymore. I use solid carbide uncoated 2 flute
endmills in place of router bits. Ultratool brand is my favorite. They deliver
cutting performance that is so far above and beyond what a conventional
router bit delivers, it isn't even funny.
For those of you who are not familiar with woodworking router bits, their
version of a carbide bit involves flat pieces of carbide brazed to a steel
shank, and set at a slight angle to get a little shear action. But the
shear angle is under five degrees. Frankly, they SUCK.
After using those for a long time, and then switching to a two flute razor
sharp endmill instead, when you first try to take a cut you think the bit
fell out, because you don't think you're feeling any resistance!
And then the snowstorm of wood chips hits you in the face, and you realize
that it's actually cutting like mad.
Time constraints on my current projects dictate that I'll just use the face
mill for the moment, but the speeder option is something I will investigate
further as I fully expect to be making more instruments in the coming years.
Cj, have you ever tried a 3 or 4 inch fly cutter with a high rake HSS bit in it? Its a like cutting on a patternmakers lathe, and if you get the geometry right you can take a HUGE cut. Sort of like part of a big ring cutter. My other favorite is a 5" HSS shell mill, the type used for aluminum. Its fast and once again you can take huge cuts. For what you're doing I just don't think metal cutting insert tooling is the way to go. The above cutters work just fine at 1800 rpm!
Use a watercooled direct drive motor/routerhead and a VFD - Check around and see what folks are using on cnc woodworking routers. I can't remember all the names, one is "Perske". Saw one on CL the other day.
here - firstname.lastname@example.org
Last edited by stoneaxe; 12-04-2010 at 08:25 AM.
I'm with Richard Newman and others. Mines a 3-1/4HP router, accuracy of a mill, any angle.
It can go together in several configurations, directly under the spindle, out to a good reach and some in between.
Several less planes of motion than mine will get most jobs done. In addition to the quill clamp, there is a draw bolt.
By mounting a pair of 20mm posts, I retained plunge capability, good when the angle doesn't match the Z travel.
This allowed a sturdy mount without having the base plate always in the way, tool changes a snap.
It's fed through a 15A speed control, I've used a 10" TC saw blade on it.
My foundry pattern work has never been more accurate.
That is the exact router I have and would want to use. Hitachi TR-12 plunge
router, 3.125 HP, 22,000 RPM IIRC.
Wanna make me a set of those mounts since you've got it all figured out already?
That's really slick Bob.
Originally Posted by Robert Campbell Jr.
A VFD is capable of spinning that motor faster.
The bearings might be the weak link in that proposal.
I assume a 1750 rpm motor. You haven't mentioned the sort of motor, or a VFD. Your motor is single phase? Then a VFD wouldn't help.
If you set up a vfd for 180hz, that would give you 9300 rpm. The bearing issues are your responsibility.
Some combination of VFD driving a 3 phase motor, with a mass-production quill mounted speeder is probably the right path to take.
Of course, the speeder might have limits on input rpm.....
I realize the Real World has budget considerations, but Time Is Money, also.
The Tormach is in stock (I guess), the cost is less than $900 , and it can tolerate high rpms
It's a lot of money, I guess, but so are custom-built guitars. You would be able to make it back on the next 2-3 guitars, right?
Speed rated to18000 RPM for continuous operation, and up to 30000 RPM for short duty cycles.
I can understand the stock router with an adapter route. But it I wanted to move on with my plans/life, I would probably get the Tormach, see how that goes, and be prepared to do what it takes to install a VFD & motor combination for any additional RPM increases.
If you decide to build it CJ, a few notes, since you'll be using the same router.
I have two of those routers, so I cannibalised one of the bases for it's plunge tubes.
Wish I could remember how I finally removed the roll pins but all I can remember is that it took way to long to find the way
without destroying the base. The roll pins are driven into blind holes.
I do however, remember how I drilled the roll pin holes in the new base, through one side on the drill press, insert plunge tube aligned to hole,
(light press fit, and locktite on final assembly) then using a cordless, finding the way to the other side then completing the hole all the way through!
All it takes is a vertical mill and a rotary table. I made a fixture, a couple of square plates with a 2-1/2" dia. X 6" tall tube
welded between them.
This to center on the RT, (with a pin for repeatability) the upper plate held the al. angle, elevated on 3 stand-offs, (to clear protruding end mill)
with a center bolt and adjustable anti-spin tabs, so the vertical leg could hang down, allowing a short reach with the end mill.
All the machining on the top of this fixture was accomplished while mounted on the R.T., assuring concentricity and level standoffs.
CJ, the rotary table fixture is available to you for the price of postage both ways. After that, the build is quick, easy and very effective.
I used a 20mm end mill to power ream the plunge tube holes, predrilled to 3/4".
The material is 6" X 6" X 1/2" aluminum angle. Every threaded hole has a steel, threaded insert. I happened to have some
knurled inserts with slight flanges. Though I have a large Famco arbor press. I just pressed them in place with my vice.
If you examine the arc'd slots and their 3/8" bolts, you'll see that each joint is able to cover any point in 360°.
That's because the slots exceed 90°, (about 110°), which when combined with the 4 threaded inserts, 90° disposed,
provides the full range.
In the interest of longevity, I machined the steel bars to pivot on the 1/2" center bolts and span across the slots for a solid
bearing surface. In no case does does the aluminum meet a fastener but is just solidly clamped in place by them.
Probably unnecessary but I made thin, (.005?) full diameter SS discs to separate each joint, in the interest of avoiding any chance
for the aluminum to gall.
I was a lurker on this forum for a few years, 'til someone asked the same question you did.
One of the reactions to it was something like, "That thing has more joints than Tommy Chong, (of dopers Cheach and Chong),
how do you tram it."
It's really simple. Most of the time it serves in some awkward position that doesn't meet the description "tram",
or I wouldn't have bothered with anything past the quill clamp and the router plunge plate.
When dead vertical is needed, I just get each in the position I want for appropriate reach, leaving the last 2 planes to deal with individually,
just like a vertical mill with head "nod" and "tilt". For pattern work, a length of 1/2" drill rod and a square on the table for X, then Y, is more than good enough.
A couple more shots of it, actually doing work.
@ each joint, it may be assembled 4 different ways, upper to left or right of lower and each of those with the lower
leg stretching either to the left or right. It can be arranged vertically, directly under the quill and infinite other arrays.
In the below photo, the lumber and C-clamps on the left, were my safety shield, behind which I stood as I cranked the X, speed control way down.
It actually took me longer to sketch, add everything I could think of that would enhance it and to accurately draw the plans, than it did to build.
Some years ago, I bought those 2 routers new, for $169 each, second one ready at hand should my spare motor brushes fail to revive the first.
Hitachi has discontinued this router but they make a modern equivalent on the same 20mm post centers, for near instant replacement. If it's wood you
are cutting, I don't believe you could improve on the results, no matter how many $ you are willing to throw at it and it works aluminum very well too.
PS, what a drag to have to add a bunch of returns so that one need not scroll to read this post.
Holy crap! Sure beats a radial arm saw, don't it?!?
I've done my share of woodworking for a few decades... for small router bits/endmills I'd do this one - a die grinder on bracket. Will handle 1/4 inch.
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Would I buy their German die grinder? Probably not; my Milwaulkie will work just fine. I'd even make my own brackets
The advange of putting it on the spindle and not the shaper mount is that you still have the z axis motion with with spindle, and don't have to move the knee for the same effect.
BTW... I do like the Hitachi MV12 (TR12?) mounted as above. I have a pair of those routers - one of the best ever made. Nice work.
Robert Campbell Jr.... love that set up. Like some of you I am a life long woodworker and that saw is a little frightening. Depending on rpm, I might want a remote control operating from the back yard.
I have no skin in this game, but personal experience with wood is, the higher the rpm, the better, so long as the cutter rpm is not exceeded and the speed can be adjusted around resonate speeds. Also the idea of loosening four bolts on the BP and swinging the head around seems easier than mounting and demounting the adapter. Which ever way is chosen, a big concern is a collet system that holds the cutter and does not allow it to walk.
Relief clearances for wood are generally higher than for metal. How do you handle this and is there a problem with resin buildup?
Not sure if those questions were directed at me Tom but if our mills were side by side I'd enjoy racing you with the mounting our 2 different sub-heads.
Originally Posted by TDegenhart
That router always remains mounted on the attachment. I just slip the clamp over the quill and catch the fixture with the draw bar, snug it, tighten the clamp to the quill and a final pull-tight on the draw bar. At that point I'm where you'll be, however long it takes to get your overarm turned 180° in the horizontal and retightened, assuming you always leave your cutting head in place and if not, then also mount it in what ever way it requires. The difference is that I now have an infinite array of cutter positions that I can adjust to, that will cut to any point from inside an imaginary sphere. A fixed vertical spindle wouldn't work for my needs.
To achieve that, I had to make it, as I couldn't find anything that achieved that criteria.
In metal work, die makers are one of the few places where draft angle (to release what is molded), is required. That is also true of wood pattern making for foundry work, the reason I built mine and mounted it on an old Index vertical milling machine.
In hundreds of hours of work, some of it on non-ferrous metal, never has a cutter "walked". It just hangs in the collet chuck as Hitachi intended.
I don't quite grasp what you mean by, "Relief clearances for wood are generally higher than for metal." nor how it might apply to this subject. Yes, relief angles are usually greater on router bits than on end mills, the heaver cut in metal requiring more edge support than when cutting wood. It is that required support that metal insists on, not that it cuts metal better by being "blunter", necessarily. Also, resilient wood compresses to a much greater degree under the force of the cutter, requiring a deeper rebound area behind the cutting edge. It's helpful if the cutting edge is outrunning that rebound too, like the screaming RPM of the router.
All that said, I've often used endmills to cut wood with this arrangement, to no noticible detriment, like some girls, wood's easy.......
Pattern makers usually avoid resinous woods, so "resin buildup" has seldom appeared, though when it has in other than pattern work, it is handled the same as if the router had been guided by hand, except that the bit is held solid in my fixture while the solvent rag is removing the resin.
Below, a 15" diameter aluminum mold that the Hitachi happily chewed out, the weary RT cranker a little less happy....
Since some will wonder how the arc'd segments were centered, I simply made a sub-plate from a Corian counter top, sink cut-out that was handy, mounted it on RT and drilled a circle of 36, 1/4" holes, 10° apart. I then screwed it to the aluminum disk and each hole in turn was pressed over a 1/4" dowel mounted in a metal sub-plate on the RT, the dowel located the distance of the cut radius from the center of the RT. That and the fixed part-centering bolt on the sub plate, made the changes quick, easy and fool proof, though laborious. Cut with a 7° (included, 3-1/2° each side) tapered end mill.
Bob, thanks for the response, but, no it wasn't directed to you specifically.
I did a small amount of woodworking years ago but now nothing. I was more interested in general comments that I could pass along to a friend who is a woodworker.
The questions I raised were issues he has had: bits moving because of poor collet design or manufacture, resonate issues, pitch build up, speed to get a good cut... He is not a professional woodworker, but on the other hand, he is not Sears. The equipment he buys is not cheap and is supposed to be high quality but, from my prospective, poor design and lightweight. Mostly aluminum and plastic.
Nice looking pattern work. You should start a pattern shop.
Thanks Tom but I have a full time job as Mad Inventor, emphasis on the "mad" part.
Originally Posted by TDegenhart
Pic below of the as-cast product of that milled aluminum mold (some steps left out) and another part, with sprues, risers and runners sawn off.
Looks like you are building a Pelton impulse turbine.
Personally, I bought a speed multiplier that came with an integral CAT40,
disassembled the thing, and then rough turned and finish ground the ass
end to a .875" stub that I stuck in a solid holder for my machine.
Total cost was $200 for the speed multiplier and three hours of my time.
It's a 6X multiplier, and I run it at 2,500/15,000 ALL THE TIME. (.030" end mills and engraving tools)
A great price for a good 6:1 speeder! Congratulations.
As to my hijacking this thread, sorry. If I have more off-topic things to say, I'll start another thread.
Yeah, thanks. I thought it was a smoking deal at the time. (:>)
Originally Posted by Robert Campbell Jr.
I've been meaning to talk about them for some time, because being a gear guy, I assumed that they
were simple planetaries and had even modeled up one to make for myself (right before finding the one I bought).
They are not. They're even simpler.
It would be almost trivial for most people of decent shop skills to make one for themselves.
They're basically just ball bearings, believe it or not.