[SPEEDRE]

OK, I'm not sure this is the right place to put this so here goes. I have been toying with building a carve/duplicator and one thing nags at me. How does one control the cutting profile?. I mean as the cutter moves in the z axis it seems to follow the arc cenered by the arm holding the router. I would think that one would have the z axis move at a constant verticle position at all times, unless it's direction is 3d as in spherical shapes. In designing the machine I have made motion study drawings and always come to the same conclution, the arc shape. Can anybody help?

[turmite]

SPEEDRE,
You have the concept correct. I am curious though if you are refering to a manual duplicator or a computer controllerd machine. I have owned several different manual trace duplicators of two different designs. The most common is the one like you describe where the z axis is mounted on a pivot that allows the up and down motion. there are other designs though that don't use that concept. One machine is a 4 axis Don Allen built using a parallelogram. The other is a Honeig 3 axis machine that is built much like a moving gantry based cnc router except all the xyz movement is suppliet by human arms and hands.

No if you are asking about computer controlled carvers, that is a different story. All of the one I have seen are basically a 3 axis cnc machine with a 4th axis mounted to hold the piece to be carved. They work in the same way as a milling machine does. Up, down on the z with no pivoting and no arm.
Mike

ps I use a 4 axis wood router as my carving machine now.

[SPEEDRE]

I was refering to the manual type. I plan on useing it to carve guitar tops and other usefull things. But I 'm still troubled by the arc profile, I want to keep it verticle as i cut following the given shapes. To keep pockets and such even all the way down and around.

[turmite]

SPEEDRE I just tried to upload a jpg of a new machine I have designed and hope to start on soon. I don't know if it made it or not. I kinda like guitars myself but my main business is gunstocks. The arc movement will not be a problem as long as you keep your stylii and your cutters to the same dimensions. Where the stylus touches you will get a cut that is identical as long as the two are the same and the machine si built well as square.
Mike

[turmite]

SPEEDRE I need to add a caveat to the last post. If all you are going to do is carve the taop then the manual will work like I described. If you plan to cut pickup pockets build yourself a cnc machine instead.

Mike

[SPEEDRE]

ah ha the trick I could not see. I guess I was over thinking the operation of the cutter. thanks

[SPEEDRE]

for pickup pockets also. I don't think it'll be that bad. I just need to keep all movement relitive to the stylus right.

[turmite]

SPEEDRE the problem I had while trying to inlett the action area for gunstocks is that the z-head is moving in an arc and therefore cannot cut a flat bottom hole or pocket. Here is an example of what I mean. this is drawn using a 24 in. distance from the c of pivot ot the c of the router motor. Actual pivot for this cut is to the outside of the 3/4" flat bottom bit that sticks out of the bottom of the collet by 1". It measures 42.7894 or something close to it. The two green lines represent the arc from pivot and you can see at the bottom of the 1" deep pocket there is a good deal of material that is levt that you will have to take out by hand or use a router with templates. It actually measures .206" .

Mike

[SPEEDRE]

turmite sir this is the problem I want to eliminate. I want to do really cheaply and fairly simple. Any ideas?

[turmite]

Speedre there is only three easy ways to eliminate it. One is with a duplicator that operates like a mill in the z, straight up and down. The other is one of the parallogram duplicators and the last is a cnc. You can of course use a mortising drill to square the bottoms up but thn you have the fixtures and the hand work. In my humble opinion your best bet is a cnc. You will have but very little more invested in it by the time you get a machine made and the bonus of the cnc's capabilities far outweigh the cost. I am in the process of building another duplicator presently and will have more in it that I would a small cnc. I have to have one because of the one off type jobs that I simply cannot take the time or spend the money to have a program written. I also have about 100 different patterns laying around gathering dust that needs to be put to work! Email me off list at [email protected] and of course take out the I hate spam to get it to work. I have something you might be interested in.
Mike

[ddgman2001]

I think carvers are great for roughing in carved tops and contours, neck carves etc. The really high-end ones are probably capable of efficiently doing accurate pockets although I've never seen one used in industry for those purposes. I can't see them being as fast and efficient as an overarm router for profiles and pockets.

If you're building less than 12 guitars a year a hand held router with templates is the most cost effective way to go. If you're doing more than 12 but less than 100, an overarm router will really speed production and capability. The good ones can be setup extremely accurately. Over 100/year you could look at CNC, but there are a lot of companies doing that many a day with overarm routers.

http://www.grizzly.com/products/item...emnumber=G9981

[dbassva]

it doesnt matter if the stylus arcs or not....it only cuts where the tip is touching the master......how the router and stylus get there is of no consequence.....it only cuts what it touches, making an exact duplicate....the router and stylus move in exactly the same manner...i have a gemini wood carver from allred....its the best on the market.....i might be willing to part with it if you want to buy one at about half the price.....weve done guitar necks, prs archtops and lynch bones guitars with it.....but i will say this, duplicators are not idiot proof machines...you need to have some skill to work them...i wouldnt use a carver for making the whole guitar...you are better off using a hand router....it takes a long time to cut the wood with a duplicator...what we do is cut them on a pin router first and do all of the pockets and then take it to the duplicator to do the carved top.....same with a neck...we will cut them out on a pin router and then take them to the carver.....except i rarely do this..i can shape a neck with a pin router in half the time it would take to even set up the neck on the carving table, so why bother

[dbassva]

overarm routers are great and in some cases just as fast as cnc....however, again you need some skill and its easy to make mistakes..i wouldnt go with anything grizzly though, unless you are strapped for cash....i have a whole shop full of grizzly and its basically a waste.....depends on the machine though....if it doesnt have many moving parts like belt sander or a bandsaw then you are ok....id stay away from planers and the overarm router....on my grizzly router, the pin isnt matched well with the bit...weve learned to work around the problem...you can get over arm pin routers cheap used...you can also make them pretty easy.....and if you use your machines daily, expect to be replacing all the switches on grizzly stuff.....their machines seem to always go down during extreme busy times

[ddgman2001]

overarm routers are great and in some cases just as fast as cnc....however, again you need some skill and its easy to make mistakes..i wouldnt go with anything grizzly though, unless you are strapped for cash....i have a whole shop full of grizzly and its basically a waste.....depends on the machine though....if it doesnt have many moving parts like belt sander or a bandsaw then you are ok....id stay away from planers and the overarm router....on my grizzly router, the pin isnt matched well with the bit...weve learned to work around the problem...you can get over arm pin routers cheap used...you can also make them pretty easy.....and if you use your machines daily, expect to be replacing all the switches on grizzly stuff.....their machines seem to always go down during extreme busy times

Good points. I've been assuming Grizzly quality has been on the upswing over the last couple of years.

Can you not adjust the pin mount relative to the bit. We have an SCMI R8 where the pin assembly bolts to the table and allows "perfect" alignment.

What material did you use for the carved top master?

[dbassva]

the pin doesnt adjust to the head.....when i told grizzly about that, it started a ton of confusion.....its not worth shipping back 900 lbs of tool to fix......you can buy a nicer pin router used for $500 if you look hard....

i made a carved top master out of mdf using a real guitar as the template......ive pretty much have a giant library of guitar templates that were made from actual guitars.....now im focusing on getting them on computor so i can cnc them out...

[corrie]

Hello all and happy holidays.If you are interested ,go to www.copycarver.com. This man came up with his own copy carver and utilizes a swing box for the y-control.A basic carriage that rides on rails with gym wieghts as counter balance .Front of swing box has router mounted on one side and uses a drill chuck to hold the stylus on the other side.I,m sure you could revamp the setup with proper linear bearings and rails for smoother action and downsize the swing box,anyway check it out it,s pretty cool.I made two of these one large and one small.Although I used them for a while ,I got tired of doing the routing part manualy so I chose to go the cnc route.Cheers and enjoy.

[Dogfart]

Hey all I just got off the phone with the guy who made a "duplicarver" for PRS. Its massive! So this leads me to my next question, hows this gemini carver for stability if i just want to cut the profile of guitar tops. How clean is it with regards to whats left to sand really rough or minimal.??


thanx newbie here

[dbassva]

well, PRS doesnt use that duplicarver anymore....everything they do is done on some Fadal CNC mills.....but as far as the gemini carver goes, its the best made...very stable and accurate...i have one.....weve done a few prs clones with it with no problem.....as far as how clean it carves, thats up to you and how many passes you take with the stylus...generally not much sanding is needed...if you want to buy one or have anymore questions let me know....im selling mine since i have gotten into CNC and i dont really use it much

[Dogfart]

ok so lets talk about your machine carver ect. Would love to see some pics of your work done by it as well as the condition of the carver. Basically im interested.

[gregmary]

Here are a set of plans for a dupli-carver. Maybe you have seen these.