Alternatives to spoil boards
Most CMS machines are built with a manifold of air and vacuum fittings on the front of the tables. If you don't have this already, you can probably add it. There are several shapes of steel vacuum pods, which attach to these fittings allowing you to put vacuum wherever you need it. Call CMS about these pods.
Have you tried using bleed-through vacuum? You will need a high volume vacuum pump, but it is a very flexible way to hold parts that are over a minimum size of about 100 sq. in.
From contributor D:
An alternative to spoil boards, albeit an expensive one, is a programmable pod bed. The bed is made up of a vacuum pod matrix, and any individual pod can be raised or lowered according to program. I worked with Heian in the mid 80's to develop their first machine of this type, and it has been working very well, day in and day out ever since. These beds are now available from CMS, Shoda, and Heian on new machines.
It is not impossible to retrofit a machine with such a system, but it is a tall order.
The advantages of such a system are that fixtures are completely eliminated for panel parts, there are no consumables (bleed board), the vacuum pump can be relatively low volume, and setups are accurate and quick.
The Heian system that I put in in the 80's will go from chip to chip from one setup to another in less than a minute, and a good bit of that time is taken up with automatic tool changes.
We have been using a Carter Flip pod system for about 5 years. As stated above, most pod systems have their drawbacks and limitations, but so do spoil boards. Our pod system has made setup time very minimal. One drawback is that if you are running a part that doesn't cover enough pods for sufficient vacuum. But you can put a small spoil board on top of the pods to help this situation. Contact Carter Products in Grand Rapids, MI. It doesn't eliminate setup problems, but it does make things a bit easier.
To contributor D: I’m wondering if the vertically adjustable pod system you’re describing would solve the problem of edge drilling while using NBM, i.e. having the pods raised 1” for the initial cut and then selectively raising parts higher to make clearance for a horizontal drill.
Also, what would such a system add to the cost of a new CNC machine? How far apart are the pods spaced?
From contributor D:
As far as pricing on a new machine is concerned, you would just have to talk to the machinery manufacturers. For a single 5 X 10 table with 150 or so pods, I would guess you would be into a $100K+ option. Having one of my custom machine houses do a retrofit may be a little cheaper, but would tie your machine up for a long, long time.
To keep the pod mechanism as simple as possible, I would have only two states: up and open to vacuum and down and closed. This would still allow you to do your horizontal boring, but by dropping the un-bored/already bored parts rather than raising the bored ones. I realize this forces a lot of compromise into the nest, but with so many pods, you just cannot afford to let the pod and control mechanism get too fancy. Also, it would be quite a trick to synchronize all of the pods so that they could raise a panel without breaking vacuum.
I am sure that any of the suppliers will give you whatever spacing, pod number, and pod size you need. In general, more pods = more money.
I would call CMS. They should be able to point you to a good configuration for your application. I love the modular pod system for being flexible with locating pop-ups. If you are running the bare hardwood top you will have to cover it with a phenolic sheet and place locators. I have a few good configurations I have used for other companies. There is also a pod system that bolts into the grid table. It is cheaper but does have some size constraints.
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