Machinery Choices for Slab Door Production

A discussion of which machinery will best optimize productivity: a beam saw, a panel saw, or a CNC? May 15, 2014

Question
Trying to get some figures together on the output of a panel saw, beam saw, and CNC. The output stock is 1200mm x 2400mm MDF board cut to size as standard flat panel frameless kitchen doors to be painted, no edging. Jobs would range from about 10 - 30 sheets. Waste expected 15-20%. Doors palletized. Combination of doors, drawer fronts and panels. Cut to size end product is supplied with hinges drilled. All square cuts (no curves or angles). Hinges drilled on minipress (or CNC in that scenario).

Would like to run two scenarios based on an 8 hour day, one being single operator, the other two operators one experienced, one apprentice or labourer. My calculations on the panel saw is 20-25 sheets per day single operator. A good sidekick 25-30? I've been told a single operator could pump out 80 sheets a day. 100 with a sidekick drilling hinges, sorting and packing. CNC I would imagine 40-50 sheets a day one operator, no output advantage with sidekick as operator could sort product while CNC cuts. Would appreciate your thoughts.

Forum Responses
(Business and Management Forum)
From contributor O:
This is kind of a "how long is a piece of string?" question. If all you're doing is squares and rectangles, I suspect a beam saw that will do both cuts at a time will be the fastest, especially if you can stack the sheets. The router will be the slowest but can give you parts that are ready to ship. For 50 or more sheets per day of MDF, you better have some material handling equipment included in your budget. One person isn't going to last long lifting that much onto a saw or router every day. Cutting strategies will also play a factor. Are you going to nest for least waste or maximum throughput?



From contributor P:
This has been discussed many times. The consensus is if you can book cut, the beam saw is going to do you the most good. Otherwise the router, as you have completely machined parts coming off of the router and while it is running the operator can do edge banding.


From contributor U:
He did say no edging. Instead of banding though, once the parts are cut, the saw operator could easily do the boring. If the quantities are high enough you might want to consider a double hinge borer.



From contributor P:
The point is the operator can be doing something else, which is not going to happen with a saw.


From contributor C:
Don't forget that you will also need extra staff to keep the incense burning on that CNC machine. If you're lucky you'll only have to throw a chicken bone over your left shoulder every couple of days. Most of them come with an "eye of newt" tool changer these days, so that shouldn't be as much of a problem.


From contributor M:
In my experience a beamsaw is not better than a slider unless you are cutting more than the quantities you mention. A router will probably be a better choice. Keep in mind it is not the cost of the router that will kill your business, it is the overhead of running it. Especially a high-tech machining center. Simple nesting routers are not too bad except for the massive electrical draw.


From contributor D:
I have a Biesse Rover and doors like you describe would be a piece of cake. Drilled for hinges and cut to size, unloaded and new sheet on, 5-6 minutes per sheet. Operator can sort and stack while next sheet is running. Resurface the table every 10-15 sheets run. Once output to machine, I can have an entry level person load and unload and push green button.

A beam saw would cut more if you had a large percentage of common sizes and can stack sheets, but you would double the material handling and need a secondary operation and most likely a second employee.

I must have missed something with my machine. In 8 years of running it, 6 as a pod and rail and 2 as a nested base, I don't see any huge overhead in running it. I worked on my beam saws more frequently and had more setup issues with them, not to mention you need a more experienced operator. With nested base I do more volume with less people and the overhead of an entry level person is more than my router any day!



From contributor M:
I am comparing not having a router to having one. Most small shops will have to upgrade the electrical, buy a larger dust collector. Tooling is expensive, software (not really overhead exactly) is crazy expensive. Going from a very productive shop running a slider, bander and manual line boring machines made a massive difference in overhead. Many new CNC owners are shocked. I am glad you did not see such an increase. A beam saw without a router is seldom seen these days so I was not comparing them.


From contributor M:
I also disagree with the idea that an unskilled worker should be running a CNC. Even if all they do is load panels and push the flashing green button, it takes a highly skilled person to make the most out of a CNC machine.

On the flip side I have trained green employees to efficiently operate a slider in one week. That includes reading the cut list, accounting for banana cuts, and cutting strategy. Beam saws take even less time to train. If all your CNC guy can do is push the green button, you are asking for trouble. An experienced CNC operator is often the highest paid employee. A guy who can modify a post processor, choose the best tool for a job, write G code for common simple operations, maintain the machine, troubleshoot bad cuts and make simple repairs is not easy to find, and darn sure not cheap. Or you can hire an entry level person and expect to pay more on tech support and service.

Analogies are often flawed, but I think this one applies… In the Army they put the more experienced and better trained soldiers on the bigger guns. You never see a green private operating the gun on a tank. A private could do it, my 11 year old son could do it, but an experienced battle tested and well trained soldier will make that gun far more effective.

CNC machines are capable of amazing things in the hands of a skilled operator. If you have an entry level employee pushing the green button that likely means you are the real operator. He is just a feeding mechanism.



From contributor D:
Contributor M, what kind of CNC are you running in your shop?


From contributor J:
CNC router makes a big difference, as well as what you intend to do with it. I don't want somebody doing programing at the control! Automation is key, especially for what the questioner is asking. I make sure all parts from my software run through the post properly. If they don't, fix it one time at the source (design software, order entry package, etc.), make it more systematic, less tribal knowledge. I have run Komo, Northwood, CNT motion. I'll take my well set up CNT machine with Cad-Code any day over the bigger machines (lots of reasons in my smaller shop). I don't need, nor do I want to pay for, a highly skilled operator (ever again). Just my two cents, especially since you are talking about simple rectangles and boring.


From contributor D:
I agree with contributor J. In the past we programmed at the machine. What a waste of time! This is 2013, the software and machines have come a long way. We have never modified G-code except in a few very rare cases. We don't have to select tools or change things - it's already set up. Yes, there are people that do amazing stuff with a CNC, like 3D carvings, etc. That's not what we do and not what the questioner asked about. I put together 2 videos, unedited start to finish, doing flat panel doors. Designed, output, and run in just a few minutes, including cut to size, hinge boring and hardware holes. Actual time from loading program to all parts off the machine and another sheet loaded about 4 1/2 minutes. Same doors ran on a hinge drilling machine after cut out, hinges only about 2 1/2 minutes. I'll round down and say we can get 10 sheets per hour with 1 guy, 80 sheets a day.


From contributor J:

I presume you edgeband your doors after boring on the CNC? If so, how do you do that without the cutters following the hole profile?

A suggestion: find a way to make or utilize some kind of parts pusher to let you or the machine (push/pull) slide the entire cut sheet off immediately. Have your machine head sweep the table, and then load your next sheet. Then while the machine is running your operator can label parts, or do whatever you want while the machine is running. This would drastically increase the number of sheets you could produce in a given period of time.



From contributor W:
He has little drop in pucks.


From contributor D:
As noted we have cut discs out that fit inside the hinge hole so that we can run on bander. We have looked and run test on running a base spoilboard about 1/4" thick with a second one that slides on and off with the parts on it onto a cart. It's on future to do list.


From contributor P:
Someone a while back mentioned getting bigger tracing sleds that somehow eliminated the need for doing the plug thing.


From contributor L:
I vote for the router and a good operator. Unless you are stack cutting on the beam saw the router will actually complete a sheet at least as fast and it will be fully machined. If you get a router, get the load and unload system. Worth its price! We run a Komo 5x10 making lots of odd curvy parts and average about 40 sheets per shift. Oddly it doesn't seem to take any longer to run a 5x10 sheet than a 4x8. I suspect part of that is the larger parts typically run on the larger sheet and the time it takes to load/unload manually is about the same for either sheet. We also switch materials several times a day. We run the puck system on the bander. It does slow the process down, but eliminates the secondary operation and the possible errors that go with it.


From contributor M:
Biesse Rover 27. NC1000.


From contributor A:
The panel saw comparison doesn't consider the higher efficiency saws that can do cross cutting and rip cutting on the same cycle. Our saw reduces single pattern cutting time about 35% so small jobs cut faster and large jobs cut faster. With a lift that raises up to the floating table the only time we need two people at the saw is for heavier (1-1/2") panels.