Vacuum

[siwoodworks]

You guys are probably ready for me to shutup, but I have more questions. I can't get three phase power to my shop, and I really don't want to mess with a convertor. I feel like I am pretty well up to speed on the basics of balancing CFM and vacuum.

I will be cutting 3\4" ply and some 1\2" mainly. Would the 2 Fein vac setup be enough hold down power as long as I took a pass and left a skin pass to be cut later? I would really like to start off on the lower end of the vacuum side so I could use the Bot and get a feel for what I need.I know everyone's need are different but I would like some opinions.

By the way, I talked to a slider salesman today and he told me he has never seen a CNC do much for cabinetshops unless it was at least a 60,000 dollar unit. Called Shopbot a nice entry level machine, but a little too slow. Anybody that wants to chime in on that I'd be glad to hear your thoughts.

As always thanks for the time and information.

[beacon14]

OK, for the umpteenth time it seems, yes you can use a two-Fein vac system to hold down sheets of just about ANY material and cut it, especially if you leave a skin on the first pass. No it will not suck as hard as a much more expensive system but it can be made to work and work well. Where it may come up a little short with plywood is if the sheets are badly warped, it can be difficult to get a vacuum seal established. I've had to use clamps to hold the sheet flat enough to get the vacuum to "take", once it does the clamps can come off for cutting.

No offense intended Chris, but it seems like we've just answered this question several times recently.

[siwoodworks]

NO offense taken David. I am a member at other forums and I understand it does get tiring answering what seems to be the same questions over and over. I apologize.
I was looking in past archives on the subject and wanted to make sure I was understanding correctly. Everyone's patience with me is greatly appreciated.

[bill.young]

Hey guys,

This was exactly the idea behind the ShopBot wiki...that this kind of information could be archived there and easy to everyone to find. Bill P., Ed Lang, and Harold Weber have already added some information about the various types of holddown systems in the "Techniques" section, but there's room for plenty more.

Feel free to jump in and to either add original material or copy over information from forum postings that you think is useful ...I promise you can't break anything!

www.shopbotwiki.com (http://www.shopbotwiki.com)

Bill

[elcruisr]

Chris,
your salesmans info is way out of date. Compare the numbers of 'bots sold to cabinet shops to the other makers output per year and he'll be shocked. I put out around 40,000 parts a year with one, will that keep up with you?

You will have to learn the "tricks" to maximize the machine and you will need to see what software works right for you.

In a high production environment I'm still a fan of all the vacuum you can afford. If I have to stop and clamp warped sheets I'm going to fall way behind! While that is not the case for everyone it is in my shop. With any CNC machine you have to tailor things to your requirements.

[bcammack]

"your salesmans info is way out of date."

...and he wanted to sell you a slider.

[ed_lang]

Chris,

Take a look here and see if any of this helps.

Feel free to call or email me as well.

http://www.shopbottools.com/getting_started.htm

[Gary Campbell]

Chris..
I first want to agree with Brett on the B.S. that the slider salesman gave you. He had a commission on the line.
Second.. With a little thought and practice, the 2 Fein setup will work just fine for fairly flat plywood cutting untill you get down to under 50 sq in pieces. Then you will want to employ some toolpath strategies. We use the Bot to drill hardware and assembly holes, back dadoes and blind dadoes for shelves, bottoms, tops and or stretchers. After starting doing it all on the Bot, we ordered a slider. For what we do, and the way we do it, (2 man shop) it wasnt a question of "OR" it was a question of which one is first. THe ShopBot won that hands down.
Gary

[dubliner]

As Bill said The Shopbot wiki is a great resource for previously answered topics, but who knows ! somebody might chime in with a new twist on things. My opinion is if you dont want to read the question then dont & if you dont want to answer then dont. If Shopbot is paying for the forum does it really matter. As a novice myself I get a lot of info from re-answered questions that are "Updated"

[siwoodworks]

Gary I am curious and maybe I am not understanding exactly what you mean. Why did you order the slider after doing everything on the Bot?

[Gary Campbell]

Chris...
Our cabinet construction is not very typical of most shops, and it seems to stir up a hornets nest of responses when I have compared other tools to our ShopBot. But, since you asked....

1) With over 30 yrs in the trade, if you think that I am going to not be at the table saw for a portion of my day you are wrong.
2) With the majority of our processed panels being glued up hardwoods, our best edge quality was done with multiple passes and a .010 final full depth cut. The Bot does the back dadoes, 5 blind dadoes for bottoms, top and drawer stretchers, and drills assembly and hardware holes. For sizing the panels,we get equal quality in less time on the slider. I can be sizing the panels during the time my son is sanding, and the Bot is machining. The 3rd man.
3) I want a scoring saw and the old Unisaw doesn't have it.
4) We have had a good year and our accountant says more tools is a good thing.
5) We use new mortise compression bits for our cutting ($$$) and Teak, Ipe (and many other exotics) tear them up, sawblades can be resharpened, I will not use resharp router bits.

Just remember these are the rants of an old, set in his way, cabinetmaker. (That can barely believe what the Bot is capable of)
Gary

[henrik_o]

We do not build cabinets like Gary (we're not really a cabinet shop anyway) but I can attest that I would not want to be without my ~3100mm (122in) stroke length Schelling sliding saw and it is not replaced by the Shopbot. I want, and need, both. While things would be different if we were a smaller operation (I have two employees and at times an apprentice) for me it is important to have such a saw to do things that are much quicker done on the saw than on the shopbot. Cutting out rectangles from a panel when these will not be post processed will always be faster and more economical with a good sliding saw than a CNC machine if there's several people in the operation and if we are talking about sawing out parts that are the same size, at least the same size in one dimension.

However, this is not an argument for a sliding saw versus a cnc machine, IMO. If I had to choose, I'd go with the CNC, zero doubt about that.

With a good cnc I do not need to have a super nice sliding saw, though. Our Schelling is large, but it has no bells and whistles like electric positioning etc, it's just a large saw with adjustable fences. I bought it used for $4250.

As of now, all it does for our cabinet projects is back panels and adjustable shelves, and I am seriously thinking about doing the shelves on the 'bot (they're mostly of different sizes). To be honest, as of now the Schelling is mostly used for crosscuts on various small parts, and I could do that on a much smaller saw. Still wouldn't want to be without it, but there's no comparison to the productivity increase with the shopbot.

[woodgod]

Ive been around about as long as Gary and I second his opinion if I had to choose I would go with the slider first but only because I know I can build anything I need to with a slider but my opinion is gradually changing as I learn more about the bot and its software. I still cant imagine ever being without a good saw! Somtimes I read some of these threads about how to accomplish a certain task on the bot and think I could do that with a lot less trouble on my table saw! But I also realize i'm just an old fart so I keep my mouth shut(most of the time!)

[harryball]

I use a two fein setup with a trupan 4 zone bleeder board. I cut 1/2" material in parts generally smaller than cabinets would require and it does well. The key is understanding holddown, working smart with it (i.e. careful toolpath layout etc...) and using the correct bits. I also cut 3/4" material for book cases and cabinets at times and have cut in a single pass.

As for a slider, I've never seen a slider that could...
work on it's own while I'm working
cut curves and circles
cut tab and slot assembly
drill holes
3D carve
cut 2.5D signs
or Vcarve

I've seen a shopbot do all these things as well as rip sheets and cut sheets into squares which is mostly what a slider does.

A person with a slider can lay waste to 20 sheets of 3/4" material making all sorts of rips and squares MUCH faster than a single person on the bot.

On the bot, however, after you watch for 20 minutes or so you pull your parts off the bot that can have blind dados, shelf holes, hinge holes, alignment holes/slots etc... and be ready to assemble. The slider guy will have some work to do. With the bot, while the next sheet cuts your hands are free to assemble (or watch in fascination for newbees).

A table saw (I have a 3HP Unisaw) and a slider (which I researched but didn't purchase) are very valuable tools. I used the table saw and a shop built router table/jig to produce bat houses before getting the bot. I could easily out produce the bot hour for hour in making parts until I get tired in about 2 to 3 hours. Then, sweating and worn out it's time to assemble the parts. With the bot I get a steady flow of parts, higher quality with mistakes being very rare and they are all pre-drilled for screw locations. When you look at the day as a whole, I am far more productive in finished product and no where near as tired.

The bot does not replace a table saw, the table saw is still an important fixture in my shop and I use it to cut all my part bevels. The bot will have you using your table saw far less, but you should never forget to use the BEST tool for the job.

The bot can replace a slider in most functions, but many shops can find a good use for both. I've noticed those shops with a slider generally have more than one guy working and have a larger production schedule going. The question becomes which will do the best for you first?

The bot has many advantages and can create more opportunity for profit but it does have a sharp learning curve. The slider pretty much does one thing well but not much else and is simple to operate.

My opinion is that the bot is far more useful than a slider for a small shop if you learn it and use it. My desire and need for a slider faded away after I got up to speed on the bot. I'm very satisfied with my choice and have never regretted not getting a slider.

Robert

[siwoodworks]

Thanks guys. I have a Unisaw with an aftermarket sliding table on it. I know I could get a slider and be up to speed on it quickly. And the straightlining for faceframe parts would be a bonus. But I am determined to do what's in my long term best interest. I can build just about anything I want with the tooling I have now. I just can't make faceframes and mill sheetgoods at the same time. And being one man I will never be able to do 2 things at once, unless I hire help or go CNC.

[wardsa]

I am making the "2 Fein" plunge after a fantastic 3 days in Edison, OH. Many thanks to John for opening up his shop and to everyone else who answered all my questions and shared ideas. But... I have more questions. Is their a SB file for cutting the plenum? How do I access it? Any plumbing ideas? Any pictures? I think I will do like Bill said and keep it simple, a 4 zone system. Thanks for all the info!
Terry Ward

[Brady Watson]

C:\SbParts\Vacuum

[knight_toolworks]

I work a lot of tropical woods mostly 8/4 stock. I try to not have to rip much stock as if I am ripping I am wasting wood. but it is far faster and easier to do on the unisaw. cut to length on the SCMS after the parts are cut cut them out on the bandsaw.