ShopBot Link nesting effectiveness

[Donald Thomson]

ShopBot Link Gurus,

I'm a little perplexed by a nesting layout (see below) that ShopBot Link did with a simple test cabinet I've been working with. I was wondering why it did not move part 6 between part 5 and 4 and save a bunch of plywood. If there is a problem in getting it to fit, it seems like it could have moved part 3 and 4 further down the plywood to allow 6 to fit. I used a Y nest for this as I like having long off-falls versus short off-falls.

Is there something in the nesting algorithm that is not handling this situation correctly?

Thanks,

Don

[Larry Epplin]

Hi Don. Did you try nesting in both X and Y? The nesting algorithm provides ample scope for a human being to establish his supremacy over a computer program. Manual nesting could yield better results for very small orders. However, for a reasonably big job, containing a good mix of big and small parts, it may be difficult to beat.

[Donald Thomson]

Thank you Larry,

I kinda figured that with a small number of parts the software might not be as efficient, but in this case it confused me a little as to why it lined up everything except that one part (6) and just kinda put it randomly out into la-la land when there was plenty of room to put it in line like it did with panels 1, 2 and 3.

Inquiring minds would like to know.....

[Larry Epplin]

This result is due the direction that the sheet gets filled. I'm guessing you selected Y direction. This results in Part 4, in your case, getting stuck at the odd location because it can get lower. I have found that this slight fit is due to the True Shape nesting. We do have an option for Cut Line nesting that doesn't try to do this type of fit. I will turn it on in the next version.

The sheet filling starts at the Nesting Corner. Nesting Corner is the corner on the sheet from where the nesting process begins. ShopBot Link allows nesting from four corners: Lower Left, Lower Right, Upper Left, and Upper Right.

Nesting Direction is the direction in which the sheet gets filled (and not in which the parts get nested). Nesting can be done either in X direction or Y direction.

If the nesting direction is X, then parts will get nested along Y and if the nesting direction is Y, then parts will get nested along X.
The following figure illustrates how the nesting pattern differs upon the combination of nesting corner and nesting direction.


Here is an illustration for the nesting process.

Nesting Direction Description.JPG (40.2 KiB) Viewed 29860 times

[Larry Epplin]

Don,

One more note on this. I did get your files to reproduce this nest. It does only occur in the Y Direction nest. It also appears that if I implement the Cut Line nesting option you get better results. It will be available in the next update.


Larry

[Donald Thomson]

Thank you Larry.

I'm going to try playing with the X and Y settings along with the starting corner settings to see what happens. I had gone back and forth between the X and Y setting but didn't change the corner origin. When changing between X and Y layout, I found that the Y layout was no better and still put one of the parts out into la la land even though there was room for it tucked in with the other parts. I'll let you know if playing with the corner origin makes any difference.

Thanks again!

Don

[Larry Epplin]

Don,

You shouldn't need to change the Nesting Corner to get a good result. When I clicked the X Nesting button I got a good result. See image..

FYI... The Nesting Corner can be set in Settings --> Nesting Parameters

X Nest.JPG (82.35 KiB) Viewed 29839 times

[Neville Bastian]

Hi Larry,
This is nothing about ShopBot but just a general optimising issue. We often will spend some time changing our sheet size to force the nesting to do what we want it do which is usually save a sheet. When will Thermwood allow the user to move parts around to where they want them and over rule the machine. It would to be fantastic to move a part, rotate part and even delete a part. My last optimiser which I believe came from Germany did this. Maybe Thermwood needs to license a different nesting program or did you guys write it?

The other issue is your offcuts. What is the point of having barcodes on your offcuts when 1 you don't have the information available on what that part was nor the timber species or colour? 2 you don't know the size.
You don't allow us access to the database where this information is. The operator can not quickly see what he has left over in the rack before he hacks into full sheets. This should be part of the controller software on the Thermwood and now shopbot.
This barcoding has been available for a long time now. Isn't it time it was completed? Its like buying a car without a fuel gauge.

Sorry for the rant. I know things are tough.

Regards

Neville

[Larry Epplin]

Hi Neville. Yes, manual manipulation of the nest in Control Nesting is something we wish to provide in a future version. Time for development of this feature is unknown. The material name or "timber species or colour" is printed on the label for the OffFall. I'm not sure why you are worried about the size. OffFall can be in different shapes based on your setting for Minimum Square. The basic procedure for deciding if an OffFall is useful is to simply scan the part in and nest on it.

[Neville Bastian]

Hi Larry,
I hope you can find the time for programming for the optimiser fairly soon. I have been told its been on the wish list for a least two years. I don't think allowing the optimiser result to be unchangeable is really that good. Even Boeing has manual override of its auto pilot.

With the data on the off fall being on the sticker is a bit like a winking at a girl in the dark. You know what you are doing but she doesn't.
The information is on the sticker but what you are suggesting in real life works like this.You do a job in Blue doors back in March. You have no jobs processed in blue since then. You get a order for another Blue kitchen in July but when you optimise it it says you need 4.2 sheets. You then make a decision, do you spend time searching through 3 months of cutting or do you just order 5 sheets. If the NC software had a search ability to list all blue off fall and it told you you have a 3 off falls one at .5m2,.75m2 and 1m2 you would then make the effort to find those pieces to see if they are still in good condition and their shape. In my case save $130.00 on a sheet of material. It also would save landfill something that I'm sure close to Themwoods heart.

Sorry Larry about being a broken record about retrieving this data. I didn't think having a basic database would be that time consuming to write that listed all offcut/off fall labels created?

Regards

Neville

[Larry Epplin]

Neville,

Ok, I think I am grasping what you want. There is access to the OffFalls for this purpose. In Add Sheet(s) click the OffFalls button. This brings up a list of all the Off-Fall generated on that machine. This list currently contains ID, Date of creation, and Material Name. If we worked on adding width & length would this be what you are looking for?

[Donald Thomson]

Hi Larry,

When looking at your X nest above, it's interesting to note that my X nest lays out parts along the long (length) axis of the material while my Y nest lays out parts along the shorter (width) axis. Is there something in the Link that enables you to change that orientation? My machine is set up for X being the long axis and Y being the short axis.

Also, I like to lean towards obtaining longer/narrower cut offs versus the shorter/wider cut offs. If I can get my nesting to work where I have longer/narrower cut offs I find I can better use these pieces later on. It's inevitable that when I have shorter wider cut offs, the length is always a half inch or inch less is length then what I need for another part. I hate it when that happens.....

[Larry Epplin]

You are right Don. That is interesting. I have loaded your settings and I get the nest you displayed originally in this post by clicking the button Y. From what you are saying you get it by clicking the button X. I do not have an answer for that at all.

With the Cut Line option in the next version I believe you should have better results getting the Off-Fall you desire.

[Donald Thomson]

Larry,

Thank you for the reply.

Are there any ShopBot Link settings that I might have overlooked that could change the X and Y around?

Thank you for all your help and advice on this. I really appreciate you guys a lot and everything you are doing!

I know that software development and support can be a somewhat stressful occupation. I spent over 18 years developing and supporting software systems for GM, Ford, GE, IRS-CI (the gun-carrying division of the IRS), plus many others. 7 of those years were spent as a Senior Consultant with Microsoft. So, if I make a comment like "wouldn't it be easy.... wouldn't it be better......" just fire back and tell me to remember my system development background and I'll shut up..... because I know "it ain't so easy".

Don

[Neville Bastian]

Hi Larry,
Sorry Donald for butting in on your Shopbot question. I'll make this my last entry.

Larry thanks for putting me straight on the list of off fall available from the NC software. If you were able make the approx size or even approx square meter /foot available to give a indication of size that would be great. How difficult would it be to grab that file via a network computer that we have ecabinets loaded. If we could grab the file then use our own custom database to sort by dates created, material type and sizes. We then could see what we had in off falls without interrupting the Thermwood operator.
Regards Neville