Sawgrid › Linear cutting for bar and profile
One dimension
Linear cut list optimizer for bar, tube and trim
Not everything is sold by the sheet. Trim, battens, tube, bar, profile and rebar are bought by the length, and cutting them well is the same problem with one axis removed. Sawgrid solves both in the same project.
Panels and lengths in one project, on iPhone and iPad.
The same promises, one axis less
The linear solver keeps everything the panel solver keeps. Every requested piece is either placed on a bar or reported as unplaced with a reason. The accounting of what came off every bar is closed. The result is deterministic: the same input gives the same plan today and next month.
The portfolio idea survives the drop to one dimension as well, just smaller. Three feed orders, longest first, shortest first and the order you typed them in, times three fill strategies, walking the order once, repeatedly taking the longest piece that still fits, or repeatedly taking the shortest. Nine deterministic candidates, all of them run, best one kept. As in two dimensions, the winner changes with the instance, which is the whole reason for running all of them.
What a bar carries
| Property | What it is for |
|---|---|
| Length | Overall length as delivered, before any trimming. |
| Quantity | How many identical bars you have. Zero means an unlimited supply, which is the normal case for stock you order. |
| Trim at the head and the tail | Waste cut off each end, for a damaged end or a factory cut you do not trust. Counted exactly, not estimated. |
| Offcut flag | Marks a leftover from an earlier job. Offcuts are finite and carry a low priority, so they are eaten before a full length is opened. |
| Priority | Consumption order, lower first. Same convention as the panel stock. |
Mixed stock lengths are the normal case, not a special mode. If your supplier sells the profile in three metre and six metre lengths, describe both and let the solver decide which to open.
Kerf and the allowance
One kerf is consumed per cut between two pieces, plus one more at the tail when a usable remainder is left behind, and none at an end that was already trimmed. Same discipline as the panel solver: the blade eats the bar, it does not lengthen the piece.
Separately, each piece can carry an allowance: extra length reserved on top of the finished length, for a mitre or for trimming to fit on site. It is reserved when packing, so the plan is buildable, and it is reported separately in the cut list, so you can see what is finished length and what is insurance. Sawgrid reserves the length; it does not calculate mitre geometry for you.
Who this is for
- Shopfitters and joiners cutting worktop edging, skirting and glazing bead alongside the carcass panels.
- Metal fabricators breaking down box section, tube and angle from stock lengths.
- Reinforcement work where rebar comes in fixed lengths and the bending schedule is a list of cut lengths.
- Anyone buying by the length where the leftover from the last job is still leaning in the corner.
The limits, plainly. This is straight cutting to length. There is no bending schedule, no angle geometry and no weight or cost roll up. What it does is decide which pieces come off which bar, with the kerf counted honestly and the leftovers used first.
Both axes, one project
A shopfitting job is panels and profile. A frame is bar and sheet. Put them in the same project, set one kerf, and get one shopping list.
iPhone and iPad, iOS 17 and later. Free to download.
Keep reading
The rest of the arithmetic behind a cutting plan.