Optimiser for cutting lengths

[stevieob]

I'm going to build a shed and trying to plan what I will need to construct the framework. I have my plans done out and know all the different lengths and sizes I will need, but now I want to try and work out what way will be the best to cut it to minimise waste.
I use Optimalon.com for planning sheet cuts, but I'm looking for something which I can plan to cut lengths of timber.

Anyone know of any similar program for lengths?

 

[woodbrains]

Hello,

The linear dimensions are read directly from your plan. You can buy any lengths you want from the timber supplier to within about 300 mm. No calculator necessary.

Mike.

 

[Fitzroy]

I ended up doing it manually. Once I'd thought about it I realised it was mostly in sets. I.e. I could get two stud upright and one noggin from a single 4.8m length. Then worked it systematically. I tried too hard to optimise and found in reality I was a couple of lengths short. As construction timber is pretty cheap I'd suggest not getting too hung up on it.

F.

 

[Chrispy]

Can't you just use your normal software, enter the timber size as you starting sheet size and use as normal, it works in optimax anyway.

 

[bugbear]

Even if it doesn't have the explicit option to work only in length, I would guess that if you give sheet planning software "stock" that is very long and narrow (e.g. 3000mm x 1mm) and parts that are long and narrow (e.g. 2300mm x 1mm) it will give the answers you need.

These dimensions effectively make the 2nd dimension meaningless.

BugBear

 

[RobinBHM]

You would do better by starting out by finding out what lengths your timber merchant has.

Yes its sold in theory at 300mm intervals but in practice you will with structural timber the merchant will only carry about half a dozen lengths at most.

Typically 2,4m 3m, 3.6m, 4.2m 4.5m, 4.8m, 5.4m

Also I wouldnt try and be too clever with buying loads of different lengths. Its best to try and buy say all 4.8m

You might want to see the timber packs, as you may find a pack of a particular length is better than others.

Give youself flexible options for cutting. That way you can cut around defects, ie avoid bad bows, twists and avoid knots that fall at joints.

If you have the space, long boards are often the best to minimise waste, so 4.8m or 5.4m

Its not really worth overthinking buying studwork, its quite different to sheet material.

 

[Jacob]

I'm going to build a shed and trying to plan what I will need to construct the framework. I have my plans done out and know all the different lengths and sizes I will need, but now I want to try and work out what way will be the best to cut it to minimise waste.
I use Optimalon.com for planning sheet cuts, but I'm looking for something which I can plan to cut lengths of timber.

Anyone know of any similar program for lengths?

Dead simple - you work down your cutting list in order, starting with longest pieces cut from shortest available. Requires virtually no thought or organisation and is self correcting as you go.

PS yes as per RobinBHM above, plus you might need to count your longest same lengths to make sure your timber buying will cover these, then the shorter lengths get taken care of almost automatically.

 

[bugbear]

Dead simple - you work down your cutting list in order, starting with longest pieces cut from shortest available. Requires virtually no thought or organisation and is self correcting as you go.

This is a time served heuristic; it doesn't give an optimal result, but is good enough for many purposes, and easy to do.

BugBear

 

[Jacob]

Dead simple - you work down your cutting list in order, starting with longest pieces cut from shortest available. Requires virtually no thought or organisation and is self correcting as you go.

This is a time served heuristic; it doesn't give an optimal result, but is good enough for many purposes, and easy to do.

BugBear

It often will give optimal results, depending on the stock/cutting list details. Usually any error is so small that the 'heuristic' is worth it for the time saved; you could have a massive cutting list cut and finished in less time than it'd take to set up your computer programme
It can often do better than a worked out cutting list in that it self corrects if a chosen piece proves unsuitable (knots etc).
One counter-intuitive detail - if there's a choice between two pieces always choose the worst option; e.g. the one with the biggest knots (as long as it is good enough). The knots may be perfectly OK within a large piece but too big for a small piece, etc. And this way you are increasing the quality of your stock.

 

[bugbear]

It often will give optimal results, depending on the stock/cutting list details.

You can only state that if you know what the optimal cutting solution is.

So here's a simple recommendation.

If you know what the optimal cutting solution is, follow that.

BugBear

 

[Jacob]

It often will give optimal results, depending on the stock/cutting list details.

You can only state that if you know what the optimal cutting solution is.

.....

If in doubt it's easy enough to check your result if you can be bothered and have the time to do it on paper or with a computer.
It can make itself obvious if you don't follow the descending order of size rule e.g. you find yourself with several short offcuts which would have made the longer piece you need and could have had, had you followed the rule of thumb.
Another counter-intuitive detail is to avoid the obvious temptation of cutting say a 3600 mm length into the 10x 360mm lengths you need with apparently no waste at all, only to discover that you now don't have a piece left for the 2700 length which is also on your list. Have to stick to descending order!