Throughput Problem

03/20/2014


From original questioner:

We sell frameless residential. Our workflow is something like this:

Parts come off the router and are sorted by type onto rolling carts. These parts then flow to either edgebander, bore dowel insert or are put directly into a sort preceding the assembly table for those parts such as cabinet backs that don't need to be doweled or banded. On a good day we cut 30 sheets on the router, but parts don't reach the edgebander fast enough that I can leave it on continuously.

As a result I am having to run a full batch which sits in front of the bander until all sheets are done, then I batch everything through the bander. We are able to machine and sort both those parts that need no further machining after the router (e.g. backs) as well as parts that need only to be doweled after leaving the router (e.g. nailers) but it really doesn't speed things up very much.

I have considered small batches but the waste is pretty significant, especially given that I am running a lot of prefinished plywood so all parts have to be oriented with respect to grain direction.

I have also considered a second router. For those of you running two routers, is the output sufficient that you can run your bander nonstop without cooking your glue?

Also, is there some third option that I haven't considered?

From contributor Mi


We have a setting on our bander that kicks back the heat so it does not burn. Saves restarting from room temp.

From contributor Ro


Can I ask all CNC owners (sorry for hijacking the thread) how many sheets you cut in a day? 30 is shockingly low to me. I can cut and mill (so we are comparing apples to apples) 50 sheets a day with a traditional cabinet saw and no boring machine. I'm sorry, I'm probably misundertanding but I've never heard anybody put CNC output in such simple easy to understand terms and I was shocked they don't put out more than 30 sheets....

From contributor AG


I think most experienced craftsmen could beat a cnc to the bottom of a stack of plywood.

From contributor Ma


Cant beat a CNC.
When we process 1 sheet on the CNC, whilst it is machining the previous panels are sorted, horizontally bored, edged and the scrap put in the bin. And we are not exactly breaking our backs to do this, unlike the panel saw. Also all holes are already drilled ready for comfimat screw assembly and any hardware required.
Our machining is by far the most efficient part of our operation with out a doubt, just ask our second year apprentice who operates the CNC.
I'd say about 30 sheets it about right and my machine is programed down, one so its not wearing its self out and the other is it more than keeps up with assembly.

Cheers Marty

From contributor Ro


Marty, to be clear I can do 50 sheets a day. Cut and bored (ready for assembly with all necessary holes, what we call milling), and cleaned up.

Are you saying with a CNC the same guy is also banding that same amount in a day (the 30 sheets) or is banding done by another person? I'm guessing banding with my small bander would take another day so if we are including banding I'm done to 25 sheets a day. But if we are talking two guys, I'm still at 50 a day. Just trying to get an apple to apple comparison.

From contributor Ma


Hey Robert,
Banding at the same time, same guy.
My real surprise and something we didn't really consider was the cleanliness, you are always on top of the waste.

Cheers Marty



From contributor Sn


I would like to see an "experienced craftsman" beat a cnc to the bottom of a stack doing radius works, ellipse work, cut out letters etc.
I have done both traditionally and with a cnc and wouldn't want to go back to try and do things manually.

From contributor Bi


We used to use and Altendorf then Martin slider to cut our parts. Between the yield, accuracy and speed you can't beat a router.
It is hard to compare because you will change the way you do things. If you add automatic unloading (and loading if needed) it can cut a lot, dead dead accurate into the thousandths of an inch. If you get the right front end software there is no head scratching and miss cut parts. Your yield should go up also. I also found that we could have one guy who could run the saw efficiently and a second and third that could get by. A router is significantly easier to run. We have several people that can put out the same quantity and quality. The statement I will make and the one I have heard over and over is, "we should have done this sooner".
If you are past 50 sheets a day than there are other options but depending on what you are making a router is hard to beat up until then.

Good luck!

From contributor AG


Snaglpuss,

Yours is a straw man argument. Nothing was said of radius/ellipse/letter work and I doubt that Robert is doing this sort of work. For me, and obviously you, a CNC makes business sense, but if Robert is a one man shop and doesn't want the hassle that comes along with hiring people, taking on more volume, etc, then I think that a valid argument can be made against purchasing a CNC in his case.


From contributor Ro


Original Poster

Are you able to pendulum process? Do you have a pusher installed on your machine? Or are you cutting, labeling, and offloading on the spoilboard?

When we bought our router 1-1/2 years ago we were having a problem, the router couldn't keep up with the rest of the shop. We didn't buy a pusher and wished we had. So I built a sort of manual pusher system. I will attach photos. It allowed us to load and run another sheet while I label and offload the sheet I just ran on my secondary table. I estimated that we gained %40 on our output.

We made a table at the end of the router. And what I call a "Rake" that sits over the sheet after its cut. It has a rope attached to it. At the end of the table is a pulley and we simply pull the sheet off of the spoilboard and onto the table. Works pretty slick.

From contributor Ro


I wasn't trying to bash your CNC. If it works for you great.

I already knew a CNC machine was not for me for various reasons.
1) I do need greater accuracy
2) I do not need great speed
3) I do not do employees (I have a 4 independent cabinet shops throughout our county I hire to make varying pieces for me)...I just don't do employees, less because of the employee and more so because of the red tape and regulation that comes with them
4)I run off solar power and it limits how large of machines I can run
5)I'm just an ornery cuss that likes doing things the old fashioned way and hates computers. I'd rather sit in front of saw then a computer programming it.

Thank you everyone for your responses. I know they are great machines, just not for me, but it's fun to know I'm not missing out on too much productivity at the same time.

From contributor AG


Rob,

I was the op, just posted under my first name accidentally. We have a scissor lift immediately in front of the cnc table and a shop built 5' x 10' workbench immediately after the table.

Our process is this:

As soon as the cnc stops, and I mean the very second it stops (the bit better still be spinning) we cut off the vacuum. We then press a button on the control upon which the machine parks itself at the offload end of the table. After pressing the button the operator positions himself at the scissor lift which by this time will be at a height slightly above the table. The operator tilts the sheet so that the front edge of the sheet lands flush on the spoil board. The operator then pushes the new sheet, onto the table which in the process pushes the cut sheet onto the offload table. Its important that the offload table be at least 5' wide, preferably larger because the cut sheet has a tendency to want to expand when there are a lot of smaller pieces which could result in some falling on the floor to either side of the table.

Its also important that the new sheet ride on its front edge at a sufficient angle that the pressure forces this edge flat (if say, perhaps, you are dealing with slightly cupped sheet of plywood). By sliding the new sheet on in this way you clean off the dust and chips which fall along with the recently cut sheet.

The operator then acknowledges to the router that the next sheet is loaded. Total downtime for the machine is around 30 seconds. The operator then labels the parts on the offload table (their configuration stays pretty consistent to that in which they were cut so they are easy to lablel). After labeling, parts are sorted onto carts by type.

However, rather than load these parts onto a cart I would rather feed them straight into the edge bander. This would minimize handling and also eliminate the feast or famine situation that I now have in my operations following the router.

I know that one person mentioned a feature on his bander that allowed him to maintain above room temp, but even at this it seems that you are still processing in batches, albeit smaller, but still batches.

I think that, in our system, a single operator could operate both cnc machines as well as contribute to labeling and sorting/banding parts on the offload table. The question the becomes whether this output would sufficiently supply the so that it could run full tilt until the routers were done with the job.

The thing about the edgebander is that it is the highest capacity machine in most operations but unless you can run it in tandem with the router you don't realize this high capacity and rather it becomes a bottleneck with a kitchen full of parts sitting in front of it.

From contributor Ro


Sorry, should have read-
I do NOT need greater accuracy

From contributor AG


I had also considered adding a cnc beam saw for the parts that do not get additional machining. I could cut tops, stretchers, partitions, intermediate shelves, adjustable shelves, backs, drawer decks, etc on the beam saw but, not being familiar with beam saws, I'm not sure how I would accomplish this in my software. I could probably pick up a used cnc beam saw on the cheap....

Robert - pay no attention to that. This site is full of guys who think that their CNC router distinguishes them from the masses and become emotional when someone says that they can go through sheets faster on a slider (which is true).

From contributor CR


We average 30 sheets per day. The edge bander sits next to the cnc. the sorting rack is stationed at the end of the bander we cut, including all joinery, hinge holes drawer glide holes everything, no secondary operation, edge band, sort into racking on wheels, with 1 man. and working at a normal pace. I too could cut panel rout bore and sort 50 sheets per day on a good day ,but not 7 days a week 52 weeks a year for 30 years. also we too, use a non journeyman to perform this operation, freeing up my limited supply of journeyman, so they can use their skills in other areas. From a business point of view it seems ludacris not to automate this process.

From contributor ma


I have always been amused by the 50 sheet vs 40 sheet per day arguments.

How do you sell 50 sheets per day?
Or even 40?



From contributor AG


Cris you miss his point. He neither has nor wants journeymen employees, he is a journeyman and likely enjoys the process and has made a viable business of it. It makes no sense to say that to not have a router would be ludacris just because in your case it is ludacris. There are large factories for which the idea of not having a fully automated million dollar finishing line would be ludacris, so therefore it is ludacris that you do not have a fully automated finishing line, right?

From contributor CR


AGC funny you should bring that up I will be looking into a spray machine at IWF this summer still hand apply glazes and stain but very interested in automating application of clear.

From contributor Ro


I think it's great for those of you who can make use of CNC routers. For myself it is just not the way we want to go. I don't have the long term belief in the economy to support taking on the overhead and I have built a solid group of men that the CNC would have to replace and I don't want to replace them. The CNC won't call in sick, but neither will it help me out when I'm in a pinch by doing me a favor of unloading a lumber truck when I am not available and bringing it up to my shop. There is give and take with the machine and it is just not for us but I know it's the only way for some of you guys and I'm glad it's making you a lot of money.

From contributor AG


I hear you Cris but you get my point. That said, I would be interested in hearing the outcome of your decision as I am at some point going to have to make a change in the way we finish.

We have zero automation in finish but, assuming that we are looking at similar equipment, why are you going to use it only for automating the clear?

The majority of the color in our stained product is sprayed on rather than wiped. Cefla, Makor and Superfici each make a small flatline that will spray the stain, sealer, topcoat as well as paint. I have never seen one of these in operation but as I understand it you can purchase multiple "heads" which contain your guns and hoses, which makes it easy to move from paint to clear.

Also, don't listen to the salesman if he is trying to incorporate a brush sander as they will not account for the portion of the sanding that he claims and will leave the majority to be done by hand.

From contributor Ch


Now that two posters have mentioned automated finishing...

Does anyone have a "ball-park" price for finishing lines? Say, from the low-end and up? I know that is a wide range, but if they start at over 100K I will self-eliminate my business at this time. If much less, then a trip to IWF this summer might be worth the trip.

Any ideas?

From contributor AG


I think Makor makes a sprayer that's under 100k. You can later add an oven which I don't have the volume to justify at this time......that said, I would never consider buying a used flatline but I would definitely consider a used oven.

I have also thought about installing a hanging line, which would never be automated bc the cost would be prohibitive but it would be a definite upgrade from where we are now (spray everything flat in an automotive paint booth, wait for it to dry, flip it over, etc).

Some ppl say that edge coverage is an issue and while I have never seen a machine in operation I have sold high end factory cabinets (woodmode) and there is quite a bit of texture on their edges as a result of the flatline. The hang line would allow for sufficient edge coverage as well as cut drying time in half.

From contributor La


I think kitchen shops have a different take on productivity over commercial only shops. Our output varies considerably from day to day. The CNC panel saw can cut a tremendous amount in a day if it is stack cutting. Beats the hell out of a slider. But all you end up with is a huge pile of parts, many of which need drilling, notching, curved corners etc. I personally don't mind seeing a machine sitting idle part of the day, employees are another matter. We don't use carts, I think they are likely to be wasteful. Depending on your shop size, a lot of time can be spent returning them to the start of the process. Our software allows us to separate plain rectangular parts and send to the CNC panel saw as optimized sheets. The panel saw cuts blanks for the PTP and stacks them on the conveyors that are a short ride away from the PTP. I'm not a great fan of PTP machines for panel work but got this one cheap and needed a quick increase in output. The router "only" cuts about 40 sheets a day. Operator starts @ 6:00am. If cutting primarily rectangles it can cut more but much of our work involves curves. Lots of small parts that need to be onion skinned or tabbed. Operator labels, & sorts, moves stacks via conveyor to their next operation. Then gets a different material quite a few times a day. Banding doesn't start until a few hours after routing. The machine will automatically go to idle if no parts are run. It has a small pot that doesn't take long to come back up. The pot has automatic filling.
People seem to think the way they are doing something is better/best. Might be/for them. Comparing how many sheets can be cut on a 10" saw/slider to how many come off a router isn't any where near a valid comparison.
PS I'm in the market for a laminar type case clamp, will be selling my Gannomat 260 clamp.

From contributor CR


Here's the point I'm trying to make. In the market that I'm in. and the size of my shop, and the availabity of qualified journeyman caliber employes. Im going to get my share of said journeymen. witch equates to about two. To best utilize the two journeymen I need to automate as mush as possible. A journeyman w/insurance paid holidays sick days personal days, workmans comp building overhead vehicles insurance on vehiocles and whatever I left out @22.00 per hr costs app.50.000 per yr 10.00 helper app. 30.000 per yr. compare that to automation expenses, machinery software ect. and it equates out. The ludacricy enters into the equasion when you ask for advice get said advice and imediatly start defending yourself. I got over that when I was about 40 yrs old and financialy not getting where I wanted to be. I started listening to the advisers I sought out and things got much better. In my case on a 30.000 dollar kitchen I was wasting 1500.00 -2000.00 per job. that is now fixed

From contributor AG


Larry,

Thanks for the advice, I have gained much from reading your posts. That said, have you seen the p2p machines that accept the panel fed vertically? The alignment is automatic and they also do the horizontal boring/dowel insertion. Its a different kind of machine really.

Cris,

I never defended myself and I appreciate all the advice. It sounds as though your business is not so different from my own, so I completely understand and agree with everything that you have said insofar as it pertains to you or perhaps myself but Robert is approaching this business from a different angle, so my only point was that there is merit in his stance conditional upon his business model. So 40 is when I can stop worrying about making payroll?.....

From contributor La


A CNC doesn't replace good men it allows them to put out more work per day. You can't run a quality high production cabinet business with fools at the controls.

From contributor Pr


Author, you said, "On a good day we cut 30 sheets on the router, but parts don't reach the edgebander fast enough that I can leave it on continuously".

It seems you do not have sufficient capacity at router to keep the edgebander busy always. One option which you already considered is to increase the router capacity. Another option is to optimally batch and sequence parts on router in order to improve busy time of the edgebander. The next option is overtime at the edgebander. Is any loss of time on the edgebander a loss of sales for you currently?