Small Off Cut Parts

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leigh mills
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Small Off Cut Parts

Post by leigh mills »

Hi Guys,

We have major problems with small off-cut parts, if you take a look at the images attached you will see how small some of these parts are. I know that there is no way of eliminating these parts, but maybe in the future there should be something in the program which can router out parts under a certain size at the start of each pattern.

These little parts sometimes knock others as they always tend to move about, which is understandable as they are so small. Maybe someone else has got some ideas, but for me I believe that if we could set a size to router these small off-cuts at the start of each job would be perfect.

Let me know what you think.

Thanks,

Leigh
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Ray Jorgensen
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Re: Small Off Cut Parts

Post by Ray Jorgensen »

Just a thought and don't know if it will work but how about the new input fields in the double cut part of the nesting setting? I wouldn't cut them first but would leave a skin on those parts so they don't move.
Justin Melhiser

Re: Small Off Cut Parts

Post by Justin Melhiser »

Leigh
There is not an option for this at this time. You can follow what Ray suggested, this might help hold these small parts down.
DanEpps
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Re: Small Off Cut Parts

Post by DanEpps »

I remember another post on this subject where the operator used double-stick tape to hold down small parts. I don't know if that would work for you but you can search through the forum for that post and see what other solutions were offered.
Matt Snowball
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Re: Small Off Cut Parts

Post by Matt Snowball »

I have this issue as well.

See attached picture

1)The handle is treated as a pocket cut by CN and is spiralled out gradually as it should be , however :

2)CN treats the latch cutout as a U-shape incorporated in the panel outline . All very well until the panel nested alongside is also outlined , and then an instant hockey puck is created.
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Yes I could nest with collars but the thin collar strips can move as well. Yes I could double-pass but then I'd be leaving a hard laminate skin on just about everything I cut. It would be nice if CN spotted potential nest-created pucks and routed them out as suggested by Leigh .

I know CN can't be all things to all people but it's a little odd to be able to eliminate pucks in your parts, whilst, at the same time, the machine is creating its own pucks in the nest .
jerry johnson
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Re: Small Off Cut Parts

Post by jerry johnson »

Leigh, we get off fall parts like this all the time but they do not tend to cause any problems. A lot of the time they get sucked up into our vacuum system which is kind of cool. 8)
Ryan Hochgesang

Re: Small Off Cut Parts

Post by Ryan Hochgesang »

This topic has been submitted to our Software Engineering group for reveiw, however to implement the logic to perform this sort of task, finding the small pieces and efficiently dealing with removal of them, would likely be tough. There would likely be a large amt. of machining time added to go in and pocket each of those areas so that a small off-fall is not left.
Georgi Baltov
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Re: Small Off Cut Parts

Post by Georgi Baltov »

Leigh,

does these parts damage the others as they move out of place?

I guess all of us get into that kind of problem from time to time.

The tab option in nesting is and option but the last time I used it I didn't really like the way it works. It need some improvement. May be thermwood could make them skin thickness and we can define the width of each tab and the number of tabs we use on a part. Last time I used them they stayed the same thickness as the original material. Haven't checked afterwards.

Tabs are an option I use regularly on mastercam and it works great. The parts stay attacked and don't move or hit each other. One thing I am not sure about is tabs on finished material. I am not sure if removing the tabs afterwards would not damage the material.

When the vacuum sucks these parts it's kind of cool but sometimes they get stuck in the pipes at the CNC and if they get stuck somewhere close to the spindle I could see a problem in that when changing tools. It has happened to me - the tool just drops on the ground 'cause it couldn't lock in place.

Anyhow it's just a suggestion. I will look into the tab option and check if there were any improvements made there.

GL guys
leigh mills
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Re: Small Off Cut Parts

Post by leigh mills »

Ryan,
"This topic has been submitted to our Software Engineering group for review, however to implement the logic to perform this sort of task, finding the small pieces and efficiently dealing with removal of them, would likely be tough. There would likely be a large amt. of machining time added to go in and pocket each of those areas so that a small off-fall is not left."
I understand that this may be difficult, but if the program cuts the parts needed, surely it can be programmed to eliminate the Off-Fall parts which are off a certain size. Sometimes there are hardly any of these parts, so I don’t think machine time will be that affected to badly.

Also if these parts are eliminated it will then save other parts from being damaged, which in the long term will save time as you won’t have to re-run those damaged parts. This is just something to think about as we believe that this would be a great benefit to all.

Regarding the Tab function this unfortunately won't work for us as we have 2 sided mfc board, so we wouldnt get a great finish on the side leaving the skin, after cutting by hand.

Thanks,

Leigh
Ryan Hochgesang

Re: Small Off Cut Parts

Post by Ryan Hochgesang »

Thanks for all the input as we will certainly take it into consideration.

Thanks!
David Hall
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Re: Small Off Cut Parts

Post by David Hall »

Matt,
I share your aversion to hockey pucks.

I don't know how complex the other machining is on that part, or if it's a standing production part that might we worth investing this effort, but here are a few thoughts.

If the part were a DXF file, you could draw and machine the pocket (turning it to dust), then cut the outline. DXF files allow the pocket to extend past the part perimeter, don't extend it too far or it will get cut into adjacent parts.

If you're always resizing the case, then you might consider leaving it in eCabs. Cut the latch pocket within the boundry of the part by say .004" and manually file off the nib left behind by the radius of the pocket tool.

Regards,
Dave
David Hall
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Rob Davis
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Re: Small Off Cut Parts

Post by Rob Davis »

Leigh,
We have the same problem with this and at times the small parts get shoved into the adjacent part and then you have a mess plus mis-machined parts. One quick fix we have used mostly successfully is to use a down shear cutter plus we have a "Y" in our exhaust pipe above the head and we open the pipe when it is doing small parts to reduce draft so the suction doesn't pull them free. This may not work on the really small ones you show but just a different approach that costs nothing to do. We just deal with the sawdust by closing the vent for further cutting away from this area. This does require an operator to be present and concentrating though.
Rob
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