A sideboard cut with the grain running one way
Oak veneered board, fourteen parts, and a rule that cannot be broken: the grain runs the length of the top, down the doors, and along the shelf. The interesting part of this job is what grain locking turned out not to cost.
The job
One sideboard, 1800 long, 880 high and 480 deep, three doors with a drawer above each, in 18 mm oak veneered MDF on 2440 by 1220 sheets. A single commission for a dining room, so there is no second chance to hide a mistake in a later unit.
Fourteen parts:
- 1 top at 1800 by 480, grain along the length
- 1 bottom at 1764 by 480, grain along the length
- 1 fixed shelf at 1764 by 460, grain along the length
- 2 ends at 880 by 480, grain running vertically
- 2 dividers at 844 by 460, grain running vertically
- 3 doors at 640 by 596, grain running vertically
- 3 drawer fronts at 596 by 200, grain running across the front
- 1 plinth at 1800 by 120, grain along the length
The numbers close up: an 880 carcass less an 18 mm top and an 18 mm bottom leaves 844 inside, which is the divider height, and a 640 door under a 200 drawer front is 840 with 4 mm of gap left over.
5.9 square metres of parts. Every one of them is locked. On a veneered sheet the grain runs along the 2440 direction, so a part that needs its grain vertical has to be entered with its height lying along the length of the sheet, and it cannot be turned to make the layout tidier.
What went wrong before
The maker cut this sideboard once already. The layout was worked out on paper on the bench, which is a perfectly good method and had worked for years.
Two parts came off the saw with the grain running the wrong way: one door, and one end. On oak veneer at 640 mm that is not a subtle error, it is the first thing anyone sees. Both had to be recut, and because the remaining offcuts were the wrong shape for a 640 mm door, that meant opening a fourth sheet.
So the before number here is not really about layout efficiency. It is one extra sheet bought because two parts were cut ninety degrees out. That is the ordinary way grain costs you money, and it is why grain direction is the setting people most often wish they had switched on.
What changed
Every part went in with its grain direction set. Cut Solver will then not turn those parts, full stop, even where turning them would obviously save board. The kerf was 3.2 mm and the trim 12 mm, a little more than usual because veneered board is worth protecting from a bruised edge.
Three sheets, no remakes.
Job sheet
- Material18 mm oak veneered MDF
- Sheet size2440 x 1220
- Sheet area2.977 m2
- Parts14
- Part area5.9 m2
- Kerf3.2 mm
- Edge trim12 mm
- GrainLocked on all 14 parts
- Sheets before4
- Sheets after3
The layout
Three sheets. The long parts set the shape of the first two, and everything else fills in around them.
The result
Three sheets instead of four, and no part recut. Waste is 34.4 per cent, which is high, and it is worth being straight about why.
What grain locking actually cost
We ran this job twice: once with every part locked, and once with the locks off so parts could turn freely.
Both come back as three sheets. The waste figure is the same to one decimal place. On this sideboard, respecting the grain costs nothing in board at all.
That surprises people, and the reason is dull: the parts that would benefit from turning are the long ones, and a 1764 mm shelf turned ninety degrees is 1764 mm tall, which does not fit on a 1220 mm sheet. It could never have turned. The parts that could turn, the doors and dividers, are close enough to square that turning them gains almost nothing.
So the 34.4 per cent is not the price of grain. It is the price of building an 1800 mm sideboard out of 2440 mm sheets. Every full length part leaves a 616 mm band beside it, and the widest thing left in the job is a 596 mm door, which fits, but only just, and only three times. If the top were 1200 or 2400 the number would look very different, which is the sort of thing worth knowing before you agree a size with a customer.
The thing grain locking bought on this job was the fourth sheet, and an afternoon.
How long it took
Fourteen parts is a ten minute typing job, and the grain column adds no time because it is one click per row. Running the layout took under a second, and the maker spent about fifteen minutes going through the diagram against the cutting list before touching the saw, which is time well spent on a one off in veneered board.
Which way is the grain on a sheet
On veneered board it runs along the 2440 direction almost always, but not without exception, and it is worth checking the sheet in front of you rather than the rule in your head. Grain direction covers how to set it and how to check the layout has honoured it.
The offcuts here are good ones
The third sheet leaves a clear piece 1776 by 736 in oak veneer, which is the best offcut anywhere on this site and worth about a third of a sheet. The first sheet leaves 652 by 590. Both are worth logging rather than stacking, which is what the offcut library is for.
The other five examples
Every job here is written up the same way, with the sheet count before, the sheet count after and the time it took.
- Eighteen kitchen carcasses from melamineKitchen fitting. 108 parts, 13 sheets down to 11.
- Acrylic letters nested for a sign shopSignmaking. 41 letters and roundels onto a single sheet.
- A term of plywood for a school workshopEducation. 216 parts for 36 pupils, 6 sheets down to 4.
- Marine ply for a small launchBoatbuilding. Scarfed hull pieces, 10 sheets down to 6.
- Engineered oak floor cut from lengthsFlooring. 81 pieces from 2200 mm boards, 64 down to 58.
Read on
The settings behind this job, and how to price the next one.