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madman
01-12-2007, 10:12 AM
Well here I go again, Previously i fiddled around with a huge cutter to cut rings outa wood. Well it never worked. Now i am going to try to build a machine to do the following. It will have one and a quarter inch thick wood fed through it, ten inches wide and ten foot long pieces. A series or routers cutters whatever will cut the wood into three ringss. One diameter will be 5 3/4 inch another 7 3/4 inch and the final dai will be 9 3/4 inches. Noiw this can be in two or three work stations in the same line to produce like 400,000 of them, HM interesting project for my little home shop but i know squat about machine designing Please Help Thanx Mike

Swarf&Sparks
01-12-2007, 10:30 AM
400,000?
don't wanna damp your enthusiasm (no pun intended) but I'd be getting them water/abrasive cut.

torker
01-12-2007, 10:59 AM
400,000?
don't wanna damp your enthusiasm (no pun intended) but I'd be getting them water/abrasive cut.
Wood? on a water jet? Be sorta soggy....no?

Tinkerer
01-12-2007, 11:13 AM
No I don't think it would be soggy. I remember seeing a guy that was cutting sailboat kits using a water jet... nice clean cut 3/4" thick. And on OverHauling seen someone cut some speaker rings from MDF came off the machine with very little water on them. Coarse a water jet gonna cost a few bucks but for that many pieces and it's potential for other project could be well worth the cost.

Swarf&Sparks
01-12-2007, 11:26 AM
only alternative I can think of, is a CNC router. That's gonna mean a lot of time, dust and noise.
Can't you sub it out to a water cut shop?

mochinist
01-12-2007, 01:12 PM
Wood? on a water jet? Be sorta soggy....no?nope, water goes thru so fast it never really soaks in.

DR
01-12-2007, 06:01 PM
Water jet????

How will you feed a 10" board, a big water jet machine, huh?

How fast can water jet cut wood, what are the costs involved?



Madman, you didn't say what the inside diameters are. Will each ring take two cuts, one OD, one ID?

Use the same style cutter you asked about previously. That'll likely be much faster than waterjet.

Make the cutter so it does all three at the same time, inner circle cut first, then the second, then the final one as the cutter feeds down.

There'll need to be some nice clamping of the board since the last circle plus kerf is as wide as the board.


Madman, the real question in my mind is why do customers keep giving you these jobs, when by your own admission you have no experience doing them?

jcc3inc
01-12-2007, 06:10 PM
Sir,

What kind of accuracy do you need?
My first impression would be to have made (3) saws of the required diameter
and then use a vertical mill to run them. Should be do-able!

What do you think?

Regards,
Jack C.

ptjw7uk
01-12-2007, 06:18 PM
Why not start with round timber of 5 3/4, 7 3/4 and 9 3/4 inches in diamater abd slice them to the required thickness, then sand or plane to thickness should all be a lot quicker than cutting from sheet or planks

Peter

DR
01-12-2007, 06:22 PM
Why not start with round timber of 5 3/4, 7 3/4 and 9 3/4 inches in diamater abd slice them to the required thickness, then sand or plane to thickness should all be a lot quicker than cutting from sheet or planks

Peter

I doubt it. Too many secondary operations involved there.

Besides, that isn't the problem. The problem is how to make the circles out of boards 10" wide.

Ries
01-12-2007, 06:26 PM
If the wood is an inch and a half thick, the router bit is gonna have to be at least 3/8" diameter, probably 1/2", I would think. Lotta waste there in kerf.

I know they cut wood with waterjets- I have sometimes had proofs cut from Strandboard before we cut a thousand dollar piece of stainless.
It works fine, with a 50 thousandths of an inch kerf.

They also cut wood all the time with lasers, but I dont know if they can go that thick.

If router bits are indeed the best way to go, then buying a commercial cnc router is gonna be quicker, and probably cheaper in the long run than trying to reinvent the wheel and learn on the job.

400,000 parts- at a buck apiece, you could probably pay for a cnc router in about a month in lower labor costs over manual cutting.

I used to work in a speaker factory back in the 70's, where they cut circles like this all the time, in 3/4" particle board, by just using a hinged template, aluminum, that hinged down and held the wood in place, then just manually zip em out with a 3hp router. The whole jig was mounted on up some stairs over a big dumpster- when the dumpster got full of sawdust and center pieces, they would just switch it out for an empty one.
But they only did a couple of hundred a day.

I am assuming you want either one solid circle, and two donuts, or three donuts? Are you figuring on getting the smaller ones out of the middle of the bigger ones?


I dont think three nesting hole saws would work- hole saws load up, and need to have the blanks cleaned out manually, which would be pretty slow, plus they get hot and wear out quickly. Carbide teeth, maybe.

John Stevenson
01-12-2007, 06:31 PM
Mike,
Youu never answered my previous query on cutting these circles.

can you get away with a black edge surface? If so then laser cutting will be the fastest, about 45 seconds per cut circle.

BTW for other list readers you can cut wood wet.
A water jet will wet the wood but it soon dries and doesn't absorb it into the wood the force is enough to blow clear.

Daft as it sounds it's also possible to grind wood with normal abrasive wheels under water to get special profiles.
Those little gallery pegs you see inside kitchens to hold spice jars etc are often made on copy lathes but the high volume ones are fed into a profiled grinding wheel under a torrent of water to stop the wood from burning.
This gets the profile needed and also gives a very fine finish that requires no sanding prior to finish sealing or painting.

http://www.glebar.com/machines_wood.html

.

torker
01-12-2007, 06:35 PM
Mike...what about using/forming heavy bandsaw blade into circles the size you need? I used to be a sawyer at a shake mill and we used a 3" wide blade that cut a very thin kurf. Blade was about 10' long or so. Nice big open gullet teeth that'd really pull out the sawdust.
If you wrapped it around an inner "puck" then made a clamping ring to go around it...you could then weld the blade together where it met. The inner puck would have an arbor hole. It'd be like a big geezuz hole saw but to the size you need.
You could have a couple of spring loaded ejector pins through the top of the inner puck that hit on a ring once you raised the quill...this would push down on the pins and eject the waste or formed piece. You'd prolly want to take the set out of the teeth on the inside to make ejection easier.
Just thinkin out my left ear here... :D
Russ

Evan
01-12-2007, 07:19 PM
IIRC this is MDF Mike is talking about. When you are making half a million of anything the most important consideration is time per piece. Setup cost fades to insignificance and even machinery costs are not that important. 1 1/4" MDF should be within the range of die cutting which will cut production costs to the minimum possible.

To make 400,000 of these in one year will require a production rate of around 4 per minute assuming normal 8 hour working day shifts. That means no more than 15 seconds per piece.

torker
01-12-2007, 07:44 PM
IIRC this is MDF Mike is talking about. When you are making half a million of anything the most important consideration is time per piece. Setup cost fades to insignificance and even machinery costs are not that important. 1 1/4" MDF should be within the range of die cutting which will cut production costs to the minimum possible.

To make 400,000 of these in one year will require a production rate of around 4 per minute assuming normal 8 hour working day shifts. That means no more than 15 seconds per piece.
OW! That's a different way of looking at it! Just dawned on me how boring that would be...after about the first two.

DR
01-12-2007, 07:50 PM
IIRC this is MDF Mike is talking about

1 1/4" MDF should be within the range of die cutting which will cut production costs to the minimum possible.



Die cutting? As in steel rule dies?

Are you guessing the material can be die cut or do you know for sure?

If it can be done it'd a fancy die setup. My guess is it may be a bit thick for die cutting.

Again, we're speculating because Madman never seems to give us the whole story before he asks for help.

mochinist
01-12-2007, 08:04 PM
Water jet????

How will you feed a 10" board, a big water jet machine, huh?

How fast can water jet cut wood, what are the costs involved?Probably depends on how many waterjet shops are in his area, but around here they have came down to some reasonable prices lately becasue fof competition. I have never had wood cut by my waterjet guy so I don't know how fast or what it would cost. They guy I use would have no problem loading a 10' board on his machine, that really isnt that big.
Sir john is right about the laser though, it would be the fastest, as long as he could live with the blackened wood.



Madman, the real question in my mind is why do customers keep giving you these jobs, when by your own admission you have no experience doing them?Probably because home shops typically have low shop rates, I have had customers cut and run for a brother-in-law or friend, that has a home shop before, it is hard to compete against a guy that is only charging a $25 an hour shop rate. I have no problem fixing those parts or making those parts when they are wrong and/or not delivered on time though.

John Stevenson
01-12-2007, 08:06 PM
Send the job to China, put 200,000 coolies on it, get them to do two each and you can have delivery next week.

.

Evan
01-12-2007, 08:27 PM
Are you guessing the material can be die cut or do you know for sure?

No, I don't know for sure. I do know for sure that 3/4" mdf is die cut all the time. When you start applying hundreds or even thousands of tons of pressure to something like MDF it behaves like warm cream cheese.

john hobdeclipe
01-12-2007, 08:45 PM
In all my years of working in furniture and millwork factories, I've never come across the need to cut rings on a production scale. These are rings, correct, not discs?

Can you provide a bit more info? Are these to be made of solid wood? Hardwood or softwood? What species? Or an engineered wood panel product such as OSB, MDF, or other? How accurate do the rings have to be? What are the inside and outside diameters of each ring? What kind of surface finish is acceptable, both on the top and bottom surfaces and on the cut edges? Will they be sanded afterwards? finished? Do the edges have to be sharp or will they eventually be rounded over somewhat?

400,000? Of each of the three sizes? or 400,000 total?

What is their ultimate use? What kind of delivery time is involved?

I have a couple of ideas brewing in my wrinkled up old head, but I need to know more.

mbensema
01-12-2007, 09:39 PM
Madman, something like that could be done with a template and turntable for the first OD with a shaper, next operation cuts the next smaller ring with an overarm router on another turntable and then the last ring on a third turntable with an overarm router. The bits could be custom sized so that the ID and OD of each piece is cut simultaneously. To keep the inner disk from getting damaged, you would need some sort of clamp to keep it centered, or maybe a vacuum table.

Another alternative is to do this all in one step, shaper at 12 o'clock, one router at 3 and another at 9, all cutting at the same time. Problem with that would be keeping each piece stationary during the cut. To keep production up, make multiple stations so that several could be done at the same time.

Dawai
01-12-2007, 11:12 PM
Methinks: the demand for artificial arseholes for hobby horses have went up.. 400,000 huh.

Need at least three dozen machines, all tooled alike.. Four forests to clear cut, and some of our Georgia illegal aliens to run it all.

Luckily I got a plan drawed up and ready to submit it for quotation. Parts delivery within four days I suppose.. if I can find some more encoders.

What do you do with three dump trucks of shavings?

NOW John: imagine the poor look on the kids faces when they see that dark stain around a hobby horse rear?

madman
01-16-2007, 08:24 PM
You got the job send me the bill David. Where the hell is Georgia???????

Herm Williams
01-16-2007, 11:08 PM
Before I tackeled a job like that I would check with a wood products company and see what it would cost to have the parts stamped out. they roll/stamp out sheets and molding by the truck load so just maybe this would be another way to go.
re

madman
01-17-2007, 08:18 AM
Well John i thought i had replied to your reply. Sorry i musta had a brain fart. Anyhow i did check with laser cutting (wow expensive) Water Jet is expensive. The edges can be black the outside diameter is important the inner not so much. Now the situation is it has to be done in house by ME and no outside sourcing will be permitted. I have built four machines years ago (with no real experience )and wowsers they are all still running making him parts with no maintenance so far. I guess after F16 parts and other **** ive built machines dont seem too daunting BUT this is one weird job. I really appreciate everyones input so far. I am using a vacuum table along with a pneumatic hold down device (aka thanx to David Cofer for that idea) Also am still looking at a variety of cutting devices multiple routers ect, and full automation to do it all. Also full lexan enclosure for safety and to eliminate the I vill finger poken that big spinner thing by the employees. Still am looking for that final solution though. Cutter configuration is unusual. Thanx to everyone for yer time. Keep the ideas coming Gentlemen.

Swarf&Sparks
01-17-2007, 08:36 AM
CNC jigsaw?

kap pullen
01-17-2007, 09:19 AM
mad man,

I don't know if anyone has suggested this, but how about one trepanning tool with gang tools that will progressively cut all the rings out.

Each cycle would cut three rings out complete.

The center tool would be the longest, cutting the center hole, the next tool a bit shorter to cut the center ring od, and on and on and on like that.

We trepanned holes with gang tools years ago using a vee tool to lead the cut, and finishing tools, one cutting outside, and one inside, to finish sides of the slot, and relieve the center tool.

I thought the "Bull of the Woods" was crazy when he had the thing made, but it did work machining condenser plates in steel.

Good luck and make lots of money!

Kap

pcarpenter
01-17-2007, 10:32 AM
:D If you toss an idea around long enough, things come back around. I think Kap's idea is what you pursued first IIRC. It's not a bad idea, but I guess it did not work out well for you.

A CNC router may make sense and I think they are available a lot less expensively than typical CNC metalworking equipment. Their tolerances are higher and they don't require the rigidity of a milling machine so they can be made much more reasonably ($).

A lower cost alternative is a commercial overarm router and templates as someone else suggested in response to your previous posts.

If you go the router route, CNC will allow you to cut all rings separately which is probably a requirement. once one is loose, leaving it sit there and float is a recipie for having it grabbed by the bit and get chewed or at least end up with a ding in the edge. Perhaps a vaccuum table will solve this, but I would think it would suck itself full of dust???

If this is MDF, you are looking at huge volumes of dust and lots of cutter wear as compared to wood. That glue gums bits at higher speed and also is much harder than the wood particles. You will be making several passes per ring, but even then with that depth you probably need air or dust collection at the cutter to keep the slot clear and should probably be using spiral bits to pull waste upward out of the slot. Be sure to observe safety precautions as the dust is harmful. They make a version of MDF whose trade name escapes me that is more expensive, supposedly a bit more durable, and has no formaldehyde in it.

Paul

madman
01-17-2007, 03:13 PM
Perhaps a steel rule die would work?? Whaddyah all think.??

DR
01-17-2007, 03:25 PM
Perhaps a steel rule die would work?? Whaddyah all think.??

It's a possiblity. Easy to find out, call a company that makes them, they should be able to immmediately say yes or no.

If it can be done, don't even think about making the die yourself. It'd have to be a very special one to cut that deep.

john hobdeclipe
01-17-2007, 06:49 PM
If you are cutting these from MDF or a similar panel product, you'll save a lot by cutting from full sheets instead of 10 inch wide strips. Thus, if you rip a 4 foot X 10 foot panel into four strips, then cut 9.75 inch diameter circles with a 1/2 inch bit, you'll get 44 pieces. But if you cut a full sheet, you can stagger the rows and get five rows and 53 pieces (11, 10, 11, 10, 11,) a 20% increase in yield, and a corresponding decrease in the cost of disposing of the solid scrap. That, to me, is a pile of $$$$$.

Cutting an 8 foot long sheet will yield 43 pieces full sheet, as opposed to 36 pieces if you cut 10 inch X 8 foot strips, giving a 19% improvement

A decent CNC router that can handle this can be bought new for $25,000 to $35,000 or so, with another $20,000 or so for a vacuum hold-down system that will allow you to work with these small parts. That's a good bucketful of money up front, but perhaps some research will turn up a lease arrangement that will be more profitable if you won't be needing the machine after this job is finished. A machine with two spindles will cost more, but cut way down on the running time.

If you absolutely must cut from 10" wide strips, the investment in a CNC router will be much less, as you only need a benchtop size machine instead of a 4 X 10.

Buy good quality MDF and cut it with diamond tooling.

A trepanning type tool would also work, as Kap mentioned. I think that for it to work really well, you'll want to have three equally spaced cutters for each diameter, so when the cutters break through, each piece will be held captive within the three cutters, and not sling off center and cause trouble.

I'm guessing here, but to trepan the whole set of rings in one go, at any kind of profitable speed, will require not less than 8 or 10 horsepower.

Take a few moments and wonder over to the WoodWeb site (http://www.woodweb.com/). There's a lot of info and experience there...Someone may have already encountered this and have some ready answers.