Any tips on streamlining a production run?

I make many, many wooden cases for conductor's batons (think band or orchestra conductors) for a company that makes the batons. In a procuction run I usually make between 25 and 30 at a time. About half are made of walnut and half are purpleheart.

Take a look at my crude sketch below and I think you will get the idea.

Here's the process that I've used thus far:

1. Mill material into 2 5/8" X 18" X 3/4" blanks for top and bottom half of case.

2. Using router with 1/2 spiral bit, route out interior of case top using a jig that the base plate of router follows (velvet covered foam will later be added)

3. Using 2 different templates/jigs route recess in bottom of case for the baton

4. Double stick tape top and bottom of cases together

5. Round over corners and edges of case and sand

6. Apply finish (been using wipe on poly but that is time consuming. Thinking of spraying lacquer with HVLP sprayer)

7. Mask off bottom recesses and apply flocking to baton recesses in bottom of case

8. Attach hinges and latches, install foam padding in top of cases

Any suggestions as to how I can streamline this process? Thanks.

I would change the order a bit. For instance, sticking the top and bottom together after routing to round the corners requires precise placement of the double sided tape. If you round the corners before routing the recesses you can do the taping faster and probably won't affect the routing.

Another idea would be to apply the finish to the inside surfaces before routing and cut away the recesses. In that way you would have continuous surfaces to finish without finish accumulating in the recesses. If you apply the inside finish before routing you can also put the masking tape over the finish and then route through the finish and masking tape. Your surfaces would then be precisely masked for the flocking operation.

Nice ideas, Lee.

Royce, do you tape off before flocking, or could you use a solid, reusable mask dropped onto the base?

Royce,

I'm sure you've thought about this a lot more than this casual reader, so I'm not sure if I can offer suggestions that will truly save time. However, I guess you're just asking for ideas that might suggest new lines of investigation.

You might consider milling pieces 2 5/8" X 18" X 1 5/8" (1 5/8" being for top and bottom, plus a kerf), rounding the corners and edges and sanding, then cutting the top from the bottom. This would allow you to skip the step of applying the double-face tape. It would mean less jointing and planing initially (half as many surfaces), but then you'd have the 2-5/8" wide rip (table or band saw) and jointing, planing and/or sanding the top of the bottom and bottom of the top.

Please let us know if you change your procedure, and if you do, how it works out. If you experiment, you may wish to record processing times for each step.

It probably has occurred to you that everything but milling, some dimensioning, final sanding and finishing could be done quite easily with a CNC router.

Cary

Here’s an idea that might save a bit of time.

It sounds like you are using 3 different templates. You might be able to use just a single template (cut out of ½ inch MDF perhaps) if you laid out your top and bottom on a single 5 ½ inch piece of stock that is cut a couple of inches longer than the finished case. Make a single template and screw it to the work piece (in the waste-area that will be trimmed off), then rout the whole thing using either a template-bushing or a collared bearing on your router bit in a single session. After you have finished routing, THEN rip the stock into 2 5/8 widths and cut to length.

I think this would eliminate two template attachments, and could save you several minutes per unit.

Rick

If you truly want to cut cycle time, you need to think in terms of lean manufacturing where the goal is single piece flow vs. batch processing. Then you can identify which step is the constraint in the process and work to improve that. The idea is to balance the line so that each operation takes the same amount of time.

Without knowing how long each step takes (and thus where the constraint is), we can't make any suggestions on how to build them faster. For example the suggestion of a "super template" to route both pieces at once will only help if that is what's taking the longest. Likewise the permanent mask suggestion.

http://en.wikipedia.org/wiki/Lean_manufacturing

http://www.lean.org/

Suggest you read "the goal" by Eli Goldratt

The other philosophy you may want to consider is DFMA (design for manufacture & assembly) especially if you are going to change your product - basically you need to think about how you are going to build it while you design it. This should come naturally to you as you are the builder, but there is a formal process (lots of books etc. on the subject).

Royce, I would strongly recommend the switch to an HVLP sprayer. Woodcraft has the Earlex 3000 for $150. I bought one and it is a joy to use. I would suggest you keep shellac in one container (it comes with two) and your topcoat in the second one. Deft satin lacquer sprays beautifully right from the can--no thinning needed.

A word of caution. The Earlex sprayer comes with two needles, and the larger of the two is in the gun. Swap this for the smaller one, and test your gun on a piece of cardboard or scrap. It puts a lot of material on very quickly if you don't ease off the feed rate knob!

In a production run you can line these up on a workbench (with appropriate kraft paper or other protective layer) and spray a dozen of your boxes in minutes.

When you are done with spraying, leave the shellac and/or lacquer in their respective containers. Just take a smallish jar (peanut butter size is ideal) and stick the spray tube in the appropriate solvent--alcohol for shellac, lacquer thinner for lacquer--and spray on your cardboard until the gun is clean. Then spray only air for a few seconds, wipe the gun down and you're finished.

One of the joys of the HVLP system is almost no overspray. You don't need a dedicated spray booth.

Since it sounds like you make these somewhat often, I would think that making your templates 3 units long would speed things up since you could route prior to cutting to length in multiples of 3 or even more. Just clamp the long jig to the stock and route a few. Easier to work on a long board than short pieces.

Quote:

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Originally Posted by Royce Meritt

I make many, many wooden cases for conductor's batons (think band or orchestra conductors) for a company that makes the batons. In a procuction run I usually make between 25 and 30 at a time. About half are made of walnut and half are purpleheart.

Take a look at my crude sketch below and I think you will get the idea.

Here's the process that I've used thus far:

1. Mill material into 2 5/8" X 18" X 3/4" blanks for top and bottom half of case.

2. Using router with 1/2 spiral bit, route out interior of case top using a jig that the base plate of router follows (velvet covered foam will later be added)

3. Using 2 different templates/jigs route recess in bottom of case for the baton

4. Double stick tape top and bottom of cases together

5. Round over corners and edges of case and sand

6. Apply finish (been using wipe on poly but that is time consuming. Thinking of spraying lacquer with HVLP sprayer)

7. Mask off bottom recesses and apply flocking to baton recesses in bottom of case

8. Attach hinges and latches, install foam padding in top of cases

Any suggestions as to how I can streamline this process? Thanks.

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Hi Royce.
Take a look at "The making of the SRK" videos.
Here is the part # 4. Inside routing.

http://www.youtube.com/watch?v=Xp9cTec9NB0

Look at part #1 #2 #3.
Gang cross cutting and exact ripping can speed up all your work.
Enjoy.

Royce,

Have you considered a CNC router for this application. The entire box could be routed in a just a few minutes including routing the perimeter. An eight foot board would produce a lot of boxes faster than you can route the edge prep and sand them. If there isn't enough volume to justify your own machine maybe there is someone with a CNC machine in your local area that would cut them.

Dino's Bridge system could also work, trapping the material and using a template attached to his SRK plus the Bridge for very fast rip and cross cuts. If you set it up properly the repetitious work would be safer and faster.

.