Batch run v single piece

[Just4Fun]

Does anyone have any tips for producing small batches rather than one-off pieces? I am finding it is not so obvious or straightforward as I expected, even for simple items.

For example, it seems logical to mill the timber for all the pieces in one go. This should help to achieve size consistency. However this approach means that for the last item in the batch there can be a long delay between milling and joinery which is normally regarded as a bad thing, with a risk of warping etc.

 

[Jacob]

Definitely logical to mill the timber for all the pieces in one go. Then one session each for all marking up, mortices, mouldings, rebates etc.
The key to this is working to a rod (full size sectional drawing) - all measurements and marks taken from this, never from another component, no marking up with a tape measure or scale, no back of envelope calculating.
Often stuff will get pulled straight when the thing is put together but if the bending is too bad then you might have to look at buying better and drier timber.
Worth it though as the cost benefits and efficiency of batch production are enormous - you get a better quality product at a fraction of the cost and perhaps can charge more.
One-off's strictly for prototypes, not a viable means of production, unless it's made to measure etc etc and charged accordingly.
PS - "to mill the timber for all the pieces in one go" yes but each component cut to size first unless very small in which case it's easier to plane them up in a more convenient single piece. Don't ever just plane up stock timber square all round. Yards do this as PAR but it's just for the convenience of bodgers and builders!

 

[Myfordman]

I quite agree with Jacob regarding rods and would add the use of jigs and fixtures too for the removal of any dimensional uncertainties.
This speeds up the cutting process no end.
On several projects recently - small decorative type and non commercial, I have been cutting components to final size, finish sanding and applying a sealing coat of finish at this early stage. This should keep the stock reasonably stable.
The act of cutting the joints AFTER this stage exposes bare wood on just the gluing surfaces and has the additional benefit of not raising the grain when cleaning up any glue squeeze out.
This might be unconventional but I can assure you it does work.

 

[bourbon]

Funnily enough, I made a simple wooden loco and enjoyed making it. I decided in my infinite wisdom, to try a batch of six, I HATED doing them. For some reason, the enjoyment of creating them, was sapped away. I'll still make them, but only one at a time now. Remember to ENJOY what you are doing.

 

[Just4Fun]

PS - "to mill the timber for all the pieces in one go" yes but each component cut to size first unless very small in which case it's easier to plane them up in a more convenient single piece. Don't ever just plane up stock timber square all round. Yards do this as PAR but it's just for the convenience of bodgers and builders!

This has always confused me. It would seem to me to be less work to put a rebate on one piece of stock 1000mm long and then cut it in half than to cut it in half first and then put a rebate on both 500mm long pieces. So my instinct would be to create the profile I want (even if that is square) in longer lengths and then cut off the lengths I need.
Also when using machinery there is less problem / wastage due to snipe when handling longer lengths; there is only case of snipe per length, not per component.
So where does the efficiency come from if you cut to size first?

On several projects recently - small decorative type and non commercial, I have been cutting components to final size, finish sanding and applying a sealing coat of finish at this early stage. This should keep the stock reasonably stable.

Oh, that makes sense. I have done pre-finishing before, but only because it can be difficult to access some parts after assemby. I hadn't thought about it making the wood more stable.

Remember to ENJOY what you are doing.

It hadn't occurred to me that batch production might reduce the enjoyment. As per my user name I do this just for fun so I will look out for that problem now I am aware of it.

 

[Jacob]

PS - "to mill the timber for all the pieces in one go" yes but each component cut to size first unless very small in which case it's easier to plane them up in a more convenient single piece. Don't ever just plane up stock timber square all round. Yards do this as PAR but it's just for the convenience of bodgers and builders!

This has always confused me. It would seem to me to be less work to put a rebate on one piece of stock 1000mm long and then cut it in half than to cut it in half first and then put a rebate on both 500mm long pieces.

Depends on what you are making of course but yes to very shorter lengths combined for easy handling. 500mm is not a short length

So my instinct would be to create the profile I want (even if that is square) in longer lengths and then cut off the lengths I need.
Also when using machinery there is less problem / wastage due to snipe when handling longer lengths; there is only case of snipe per length, not per component.
So where does the efficiency come from if you cut to size first?

Mainly in conserving sectional size. You have to remove more timber from a long bent piece to get it straight and square all round. Some pieces can be so bent that it's impossible to get them straight at all, but cut to length first reduces the problem. Snipe means adjustment to machine and/or handling needed. If impossible to eliminate you just have to look at final pass with hand plane.

......
It hadn't occurred to me that batch production might reduce the enjoyment. ...

I used to really like it - you can really get speedy producing neat stacks of finished components and see them piling up around the workshop

 

[novocaine]

I occasionally make doors and end panels for kitchens in the usual "shaker" style. they are batch processed.
cut all the rail and styles to width
cut all the rails and styles to length
cut the field panel
use the offcut to make the loose tenons
rebate all the rails
rebate all the styles
chamfer the edges
glue in stacks of 3 to save on clamps.

I find it far more entertaining doing a batch like this than doing 1 or 2 and the planning out of the order of operations can be interesting, especially in a small workshop using tools multiple times. By batching it this way I don't need to cut a rod as the first cut part acts as one, if I need to change a machine mid run for something else, but assuming I don't need to change settings mid way through the part run then I don't really need one anyway.

 

[Mike Jordan]

Batch production can make woodworking less enjoyable but can also enhance the experience in some cases. Some items are difficult to make at an economic price if made as required, eg one at a time. I make furniture and fittings for narrow boats and Dutch barges, some of the frequently used components I make in batches to save the time taken in setting up machines to make an odd one.
The photo shows two types of edging for use with 19mm thick veneered sheet materials. The rounded corners come in four different sizes and it would be a pain to make a pair rather than use two from a small stock. If you are making multiple identical items then it's a good idea to add a few spare components to your cutting list to cover any faults you may find during processing. If you discover a fault towards the end of the processing it may be necessary to set up each machine again to make a single piece. I also find the need to keep counting the pieces to ensure that I haven't missed one at any stage.

 

[Just4Fun]

Yesterday evening I tried the approach of cutting into smaller pieces directly rather than producing a square board first. I can't say I am a fan. One board I started with was roughly 1600x210x50 and I needed to produce blanks 400x45x18 for further processing. I was aiming to get 24 pieces from the board but I actually got 28, so had some spares. So far so good.
Then I had to flatten and square 28 small pieces. Much of that work could have been done with the board intact, or at least in a few full-length strips. Passing 28 pieces through a thicknesser seemed a lot more work than passing one large board through. It was like making toast for a coach party.

One issue I came up against was boredom. I had not anticipated this, but it seems my mind is apt to wander when feeding multiple identical pieces through a machine. Not a problem in this case, but not a way to ensure safety when using something like a table saw.

 

[Jacob]

I worked that out as 32 pieces?
You might have been OK to bung it straight through depends on details but if too bent to start with you could lose a lot of section size to get it down, as compared to smaller sawn pieces. Though your piece seemed well oversized so you had plenty to waste.
Also stuff tends to bend a bit as it is ripped and tension is released. Then it bends again as the revealed faces dry out a bit more. So if faces were planed beforehand they would then need planing again.
400mm getting a bit on the short side so maybe doing it in 800mm lengths more practical.
If in doubt cut all to size before planing, it can save a lot of work (and timber), but it's not a fixed rule, it all depends.

 

[woodbloke66]

.
On several projects recently - small decorative type and non commercial, I have been cutting components to final size, finish sanding and applying a sealing coat of finish at this early stage. This should keep the stock reasonably stable.
The act of cutting the joints AFTER this stage exposes bare wood on just the gluing surfaces and has the additional benefit of not raising the grain when cleaning up any glue squeeze out.

Whenever possible on my projects, (which are all individual jobs) I finish all internal surfaces prior to gluing, usually with a couple of coats of Osmo with wax over the top. The finish then acts as a 'resist' and means that glue won't stick to it; you can glue up at leisure (if there is such a thing) and leave the 'squeeze out' to set hard when it can be removed with piece of pointed acrylic, or similar - Rob

 

[Just4Fun]

I worked that out as 32 pieces?

You mean you would have produced 32 pieces from my board? Perhaps so. Maybe I am inefficient/wasteful. I got 28.

 

[Jacob]

I'd crosscut into 4no 400mm lengths
rip into 4no 52.5 widths
rip into 2no 25mm widths
ending up with 32no 400x52.5x25 (nominal), which should be good for reducing to your 400x45x18 
That's without seeing it but if it was definitely dry and stable maybe just start with 2no lengths at 800, but the other cuts the same.
It's much easier to get short pieces flat face and edge over the top of a planer and that should save a lot of fiddling about. After that you just feed them through thicknesser head to tail to avoid snipe.
If snipe is so bad you have to cut a bit off you perhaps need to look at the machine. But a trace of snipe which you can whip off with hand plane is usually no prob and might be left to the very end fettling once the thing is made up.
Another trick is to cut in order of size/section, biggest pieces first but from the smallest piece of stock e.g. from your offcuts bin if poss to start with.
What are you making BTW?

 

[rafezetter]

I quite agree with Jacob regarding rods and would add the use of jigs and fixtures too for the removal of any dimensional uncertainties.
This speeds up the cutting process no end.
On several projects recently - small decorative type and non commercial, I have been cutting components to final size, finish sanding and applying a sealing coat of finish at this early stage. This should keep the stock reasonably stable.
The act of cutting the joints AFTER this stage exposes bare wood on just the gluing surfaces and has the additional benefit of not raising the grain when cleaning up any glue squeeze out.
This might be unconventional but I can assure you it does work.

That's a really good tip - simple, but the benefits are obvious - no idea why I've never thought of this myself #-o

 

[Just4Fun]

What are you making BTW?

Nothing complicated or interesting. It is just that SWMBO has asked for 12 identical picture frames. When I said OK I thought she just wanted 1. Getting 48 tight mitre joints cut by hand to produce 12 frames that really look and measure the same seems more daunting to me than making a piece of furniture.

 

[peter-harrison]

I haven't made a rod since I started using CAD. Get a cheap 2D program and it will change your (working) life!

 

[Jacob]

How do you take off measurements and mark up from a computer?
Surely you'd still have to make up a rod, unless you could print out full size on card or something?

 

[peter-harrison]

With TurboCAD, which is what I use, you can either select a component, in which case you get its dimensions at the bottom of the screen, or you use one of the several dimension tools which will give rads, angles, lengths etc. I usually do a dimensioned printout or quick sketch of what I need at the time. If it's a detail I do a full size print on an A3 printer which is usually big enough. I have definitely seen a decrease in measurement and design mistakes. It's also much more flexible as if you change the design, you don't have to do an entire redraft of the job on paper and on the rod. I did a very complicated job on a club in London last year, and was able to change the design on site, from day to day, using a laptop and mouse. This would have been ever so much harder with drawings and rods.
There's also a whole area of potential mistakes that are eliminated, to do with dividing things into halves or thirds, as the program does that automatically. Of course, there are some errors you get on CAD that you don't with a full size rod, to do with visualising the sizes of things, but that comes with experience.
If you work with other people, but not on the same site, for instance metalworkers, it's so easy to email a drawing.

 

[Jacob]

I see all that but how do you get from drawing, even on A3, to putting marks on timber?
Yes the rod can be part of the drawing design process so if you've CADd everything it wouldn't be needed, except for its primary purpose; to lay on components, singly or in stacks, and taking off measurements directly with aid of a square, pencil etc.

 

[MikeG.]

I see all that but how do you get from drawing, even on A3, to putting marks on timber?.....

You can print it out, Jacob, and glue it to the timber. I do this all the time if I'm carving, for instance.