Considering CNC

      Another long thread about the realities of adding a CNC to an already well-equipped shop. April 8, 2008

Question
I own an eight man shop. We build face frame cabinets and also make moulding. We've been in business for over 20 years, and have always been busy and made decent money on our jobs. I'm at the point where I need another employee to keep up. About the only piece of equipment I don't have is a CNC. I've read many articles about how a CNC saved the business and/or replaced one or more employees. Not all my guys build cabinets, but those that do put out about three kitchens a month. Panel processing is quick and accurate with our slider, 46 spindle line borer and dedicated dado saw. Solid wood runs through the ripsaw, panel clamp, planer/sander, widebelt, a dozen dedicated shapers, face frame and door assembly clamps and whatever else it needs to. With all my existing big equipment and good guys running it, I am skeptical that a CNC is the answer. I also have Cabinet Vision and a good designer who knows how to use it. I am not afraid to invest the money in a router, just not sure if it is the way to go. Anybody else been there and done that?

Forum Responses
(Business and Management Forum)
From contributor R:
You are still making doors in-house? Processing face frame stock? Running your own moulding? If you CNC and are still doing these things in-house, it will do you no good. You won't be able to keep up with the router.



From contributor X:
You forgot to mention space. Each man is required to have so much space and so does CNC equipment. I'm assuming you have adequate space. If so, go for it.


From contributor D:
Sounds like you're ready for the CNC. Knowing the software is the biggest battle and it sounds like you have that under control. Going to CNC from Cabinet Vision is like a cake walk.

I build doors and frames all in house and cut parts on a CNC with Cabinet Vision. Doors will be your bottleneck after a CNC, though no one says you have to run the thing 24 hours a day. After all, it does come with a power switch.

I say go for it. Get a good industrial unit with plenty of tool holders. After you get comfortable with it, sell the equipment that you no longer use. A good machine and someone who knows the software can easily save you from hiring two employees. You will have to give the existing employees new tasks as some processes will change. For the better, I will add.



From contributor J:
Contributor R is correct that by speeding up one area, you will be pushing the other machines. We were cutting on slider, 2 dedicated boring units, 2 dedicated dado saws producing doweled modular casework. We went to CNC saw, PTP boring and doweling machine and saw productivity jump 30-40%. We recently went to a bigger CNC router and had to give up much more space for moderate production improvement. Basically you have to decide if you are going to nested base operations which require good software and a big learning curve (if you are not doing any CNC work now). This is a very big commitment and you should go slow. Don't let the salesmen fool you. Get their promises in writing as to what the machine will do. Talk is cheap. You should figure replacing your boring machine, dado saws, toe notching. If you are not going to go 100% nested and continue cutting panels on slider to machine on CNC router, it won't work. Your slider is not accurate enough. You need CNC accuracy. Keep the slider, though, as you will always use it. We did.


From the original questioner:
I planned on going nested base. Any reason not to? I am not at all concerned with keeping the CNC busy all day. As a matter of fact, I am sure it will sit idle way more than running. Contributor V, what type of doors and frames do you cut parts for on the CNC? We build all solid wood face frames and five piece solid wood cabinet doors. I assumed we would still do them with the chop saw and shapers even after having the CNC.


From contributor R:
Let's put it in perspective. If you are doing three kitchens a month, and you get a CNC router, you can machine all of the parts for those three kitchens in one day. Then you can shut down the router for 19 days while your guys build doors and assemble everything. You have to look at it with eyes wide open and realize that it will affect the whole shop, not just the guys building boxes. You might find that your office will not be able to keep up if you increase your production significantly. Do you have excess capacity in the finishing room? Door department? Any one of these could be a serious constraint on your ability to grow your business.


From contributor D:
I cut all my door and frame parts to size on a Whirlwind up cut with a Tiger Stop and Level4 software and a printer. This way, all cut lists for frames and doors get optimized and labeled by means of downloading cut list directly from Cabinet Vision. This method is very fast at cutting parts.

As far as cutting frame parts on the CNC, if a rail gets an arch or other shape or a stile gets flutes, or any carving, i.e. vines, flowers, pin striping, lettering, it gets done on the CNC.

For doors I make 5 piece also. I use a Unique 250 door machine, though for larger and odd shaped doors and panels, I use the CNC to machine the solid wood parts. I bought a tool holder for the CNC that will accept 1 1/4" shapers so I can just pull the tooling off the door machine and put them on the CNC when the need arises. I have a 15 hp spindle on an Anderson router so tool size isn't a problem.

Cabinet Vision is capable of shaping door panels and rails, if you need. Making doors on dedicated equipment is the fastest way. I use the CNC for special shapes and carving, engraving as well as all panel processing.

Countertops also get cut on the CNC. I also set up the CNC with a 22 1/2 and a 45 deg chamfer bit so any panels or frames that require an angle get done on the CNC. At least once a week I find a new use for that machine. Right now my slider gets turned on only a couple times a month, though I will never get rid of it. If you have room and the funds, get a CNC with a 12 ft. bed; it makes countertops easier.



From contributor T:
In regard to the purchase of the machine, some more data would have to be reviewed and then you could run the numbers to see how it comes out. If it works out that you can run all you need in only eight hours, then it may make sense to buy a less costly machine, maybe go into the used market. Otherwise, you will end up with an extremely high hourly rate. There isn't enough info here to comment on your nested based direction.


From contributor Y:
"If you are not going to go 100% nested and continue cutting panels on slider to machine on CNC router, it won't work. Your slider is not accurate enough. You need CNC accuracy. Keep the slider, though, as you will always use it. We did."

I have friends who cut on a slider and send it the CNC with perfect results all the time. They also have beam saws and they all say their sliders cut better then their Homags! What kind of slider do you have that won't cut perfectly? I plan on using my Altendorf to cut panels and send them to my Busellato 3006 for machining!



From contributor Z:
The only slider that doesn't cut perfectly is the one that a human operates. Even cutting square panels on a nested based router allows you to use non-traditional cutting methods, not to mention line-bore and cut dados at the same time. Keep the slider, just use it to cut kick material. Busellato and Altendorf are great machines, just Homag and Busellato go so much better together, just not as good as 1 Komo.


From contributor L:
To CNC! Whatever step you make, it will make you ask why not sooner. Even adding Tiger or Omga to slider and crosscut saws would be a great step. A PTP to dado and drill face frame kitchen parts and help to process frameless casework would be tremendous. We do the slider to the PTP and band. Works great and the only unsquare cuts are from the sleeping operator.


From the original questioner:
What are the advantages of using a slider and a PTP? Why not just do it all on a CNC?


From contributor C:
Good question. We have a salesman that swears that it is quicker and more efficient to cut parts on a beam saw and machine on a PTP than to use a CNC router to cut and machine. The last place that I worked used the latter. Where I am working now uses the former and parts are cut and machined slower. That is just my experience, though. What are the other experiences out there? I guess that the cost of the machinery is a major factor.


From contributor R:
Using a nested router vs a beam saw work cell has been beaten to death on this forum. The router is more efficient for small runs and the work cell wins hands down when stacks of identical parts are cut and machined. I still contend that if the questioner does not go into this with a well thought out plan, he is going to be throwing away money. I would suggest spending a little money with a consultant before you spend a pile of money on a CNC which may or may not help your operation.


From the original questioner:
I am trying to understand some of your comments. Are you saying I shouldn't be making my doors, face frame stock, and moulding? That if I get a router we won't have time to do this? If so, why not? I don't think I have to keep the router busy full time, especially if I go the used route. If the router causes bottlenecks, we will deal with them. Just because I have a router does not mean I want to expand and take on more work. That may be an option and I would deal with that when the time comes. I am just looking for ways to make my current operation more efficient. I know there are many shops smaller than mine that swear by their CNC. To be perfectly honest, I agree with your way of thinking to a certain degree. I am not sold on the CNC idea as of yet, just exploring options and finally asking some questions I have not been able to get answered by just reading.


From contributor R:
My point is, why would you buy a tool that costs $50 or $100,000 and not utilize it? A CNC router is just a tool like any other. It is not a magic bullet. If you can't keep up making doors or finishing or whatever your constraint is, you would be wasting time with a CNC. A very well thought out plan for buying and implementing a CNC router would be a first step. Step two would be to buy and use the software to run the router for 6 months or a year. CNC routers usually have a huge learning curve. It would be in your best interest to be ahead of the curve.


From contributor Y:
Contributor R, which brand CNC do you own and what area of your shop did it constrain first?


From contributor R:
We have a beam saw and PTP. We got slammed on the office first. It took a while to get the sales and design staff to be able to keep up. Then it was the finishing room, which is still the biggest constraint. I would venture a guess that we could double our production by increasing the capacity of the finishing room. But then we would have to work on the ability to sell that much product.


From contributor K:
I went to a CNC this summer and overall, have loved the accuracy of the machine. I heard once that a CNC can lose money just as fast as it can make it! This is true. The office has to be on top of programming and know the software first. Ask questions of how long it will take to get the programs written. I have a used Komo, a 1992; this took a special code with no tool changer. It has two routers and two piggyback drills. This is all we need. The routers have a 3/8 end mill and a surfacing bit. The drills have a 8 and 5 mill. This system works very well for us. We make face frame and frameless boxes and nest everything, including doweled drawers. Our machine runs about 8 to 10 hours a week. It is a little slower not having a drill bank, however if you watch your programming and have the tools up to speed, this may only add one minute a panel. This I know has tons of variables and some panels do take a long time, like a pantry or linen with long rows of drilling. If you make custom closets with lots of shelves, this would take forever, and an upper cab, not so much. Our machine was approximately 30k and programming 9k with KCDW and Art Cam.

Point being, a salesman will sell it and leave well before the payments do. You don't always need the tool changer and all the whistles. This would be cool for making signs or engraving, but we don't do ss or very many plam tops. Our time is spent making boxes. That's an important decision to make. What are your needs now and how far in the future are you going to change what you need now?

We have a five man shop with a Ramand gang rip, a Tiger with the works, a Unique shape and sand, a door and panel clamp. Contributor R was right - the doors are the holdup. Every bottleneck fixed will create another. This business is a hungry monster that will continue eating every dime you feed it! Is there work you are turning down? Can you get more efficient and have more to do? If you get slow, a worker can go home with no pay. The router and all of his electric friends will demand a check until paid off in five years or so. The router was the right choice for us. In hindsight it could have come sooner, mostly for the tolerance of the parts. Everything is perfectly square and true. They always fit once your programs are dialed in.

Are your cutlists all right now or are the shop guys editing stuff they just know that isn't right on the list? This is a hurdle I had to jump. All the computer time is very important, but hard to get to when a job has to be out the door.



From contributor L:
The reason I went PTP or machining center is because we don't have the software in place to control the router for nested. Also, we found through research that against some shops, we can assemble by the time they are done getting it past the bottleneck of the office. Honest. I also like the idea that the saw can be turned on and something can be cut that is job related without office input.


From the original questioner:
I now have one man full time in the office plus myself about 60% of the time. I am able to be in the shop some but not as much as I would like. Sounds like a CNC would require a lot more office time. Any idea how many more hours would be transferred into office time from shop time with the addition of a CNC with my sized shop?


From contributor D:
If you are using Cabinet Vision to do your drawings, with the proper software add-ons from Planit, you can get info to a nested based router in minutes. Drawing the job for the customer is the biggest part of the equation and at this point you have already done that. There is a little bit of double checking your drawings to be sure all the dados, line boring and other operations are in place before sending to the machine. Have your software salesperson from Planit show you what the add-ons will do for you. You will be amazed at how quick and easy it really is. Then go to another shop that is running the same software and a nested base machine and see for yourself.


From contributor R:
I took a few minutes to re-read the entire post and I have an idea for you. If you already have design software in place and are only cutting out 3 kitchens a month, then why not sub out your box machining to another shop with a CNC. It just does not make sense to buy and operate a CNC for just 3 kitchens per month. If you call your software company, they should be able to find a shop with a CNC that is close to you and using the same program.

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