Maximizing Profit on Low Margin Jobs

[wrustle]

One of the constant challenges we all face in this line of work, is the need to become more efficient in order to maximize profit.

Be it through tooling, set-up, machinery, or just plain old elbow grease....the song remains the same......we must get it done faster!

Keeping that in mind, the following is an exercise in that thought process....we must get it done faster!


It was a couple months ago when our biggest customer calls me up and asks us to quote some parts for him. Not a fussy job by any stretch, and the quantity was attractive at 2,400pcs, but the problem was two-fold.

One....the 2,400pc quantity was comprised of 4 separate parts of 600pcs that totaled 2,400pcs. Ok, not so bad I'm thinking....as the money signs danced around in my head.......but then he goes on to tell me, 3 of the parts are made of polycarbonate and one is delrin. All right now....money symbols starting to fade a tad as I know from experience, plastics equal MESS, plastics = BIRDS NESTS, plastics = CLOGGED TOOLS IF RUN TOO FAST.

All right,...put the brakes on I'm thinking to myself......2,400pcs! Holy crap....this could be a nightmare.

Well, to make a long story.....well......longer........


I ask him to send over some drawings for me to look at and I'll quote them up.

Drawings show up in my "Inbox" and as I open the pdf's I see problems....right off the bat,....problems.....I hate problems......I mean who doesn't, right.....but these pieces are 3.56 inches wide, by 5.56" long....oh, and here's the fun part!....... .030" thick!

Oh well....what's the big deal, right?.....there's only 600pcs to make.....I should be able to figure out something.........UGH!

So, ok.....as I go through the other prints, it's not so bad.....next 600 pc lot is .06" thick, after that is .125" and finally .250".

Ok, part size definitely dictates fixture, part geometry confirms it (four corners with a .125" radius) with no way possible of holding the thinner pieces in a vise....so it's off to the drawing board.....or as we call it in this trade......the CAD board........Ok...bad joke.....sorry.....


So I design a fixture, get my material quotes in, figure my labor charges and present my pricing to the purchasing agent.

Wait.....do I detect a laugh?


Ummm....yup.....I definitely heard a laugh.....or maybe it was a gasp.....


In any event, I was told my pricing was WAY out of line with what they had been paying.

Now, my usual response to a statement such as that is, "Well why don't you just go back to who you were using before?", but I bit my tongue (being this was our best and biggest customer), and politely asked if they would be willing to give a target price since I was not even in the same STATE that the BALLPARK was located in.....obviously!!

So a target price was given and as I jotted down the pricing on each drawing and hung up the phone, the first thought that came to my mind was, "Are you fucking kidding me?!?!"


So, the wheels began churning.

Ok,.........what if we stack these and machine several at once?


Sounds more than reasonable, but fixturing can be an expensive proposition, so maybe we can incorporate the same fixture for all the pieces thus deferring the initial cost over the entire 2,400 parts.

Thus the project began.


The part thicknesses being all divisible and/or multiples of eighths made the design fairly simple once the light bulb finally came on!

So starting with the thickest pieces at .250" thick I designed the fixture to accomodate 3 of those pieces stacked up to be machined at once.

I needed to locate the parts square and have access to the corners to mill the .125" rads on the corners. There were two .160" dia. drilled holes in the centerline of the X axis equidistant from the edges so that was a non issue, but the corner rads were.

The parts must be held in the middle along the sides.....I'm thinking toggle clamps for work holding and quickness for loading/unloading.

I had to have a tool with a minimum LOC of .750" and be stout enough to not vibrate taking a cut .750" deep.

The parts being a polycarbonate were just begging for a HSS end mill, but I decided to go with a .500" carb variable flute aluminum specific end mill as my first choice. I figured the aluminum specific type end mill with razor sharp edges would work just as well as a HSS end mill would with the added advantage of being both carb, and variable flute to keep any vibration either nonexistent or minimal at best.

With the fixture design and tooling figured out I was able to come up with a much better plan of attack on these parts.


The .250" thick pcs. could be done 3pcs per cycle, the .125" pcs could be done 5pcs per cycle, the .06" pcs equaled 10pcs per cycle, and the .030" pieces we figured at 20pcs/cycle.

Accounting for the load/unload time, milling, drilling and deburring and I was well under the target pricing. Son of a bitch.....who knew.

I emailed back my pricing offering to do them at their target price, and was promptly awarded the job with a PO showing up shortly after submitting my pricing.

Production began, and once the cycle times were confirmed (we keep a stop watch at every machine) we actually ended up making just over double our shop rate.

So to sum it all up......just because someone else can do a job a hell of a lot cheaper than you does not necessarily mean they are bottom feeders......it could just simply mean they are able to make things much more efficiently than you can!

Best Regards,
Russ

Here's a pic of some of the .125" thick pcs stacked in groups of 10 ready to be loaded onto the fixture.




Here's the fixture I designed and made. It really is nothing extravagant, and is very simple, but WOW...what a money maker it turned out to be.



Here's the fixture all loaded up ready to go in the machine.






Fixture is loaded into the machine ready to go!




Parts are all done.....10pcs at once. Corners milled, holes drilled.



I even made two fixtures so while one is running in the machine, the operator could be getting the other unloaded, and loaded back up waiting to go in!

[DaveH]

Now that was well thought out,
I hope you charged them for your thinking time

DaveH

[EdK]

That's a great story Russ. And all in one post.

Ed

[Mayhem]

(06-05-2013, 06:04 PM)EdK Wrote: That's a great story Russ. And all in one post.

Ed

Very good Ed Did Russ end up finishing off that thread...

Nice work Russ - always good to see these things from a different perspective.

[PixMan]

Nice work Russ, glad you got the job!

Just make sure you get all that plastic swarf out of the machine as it'll wreak havoc on your coolant stability. It can close off the oxygen supply to the coolant and that is just what bacteria needs to start multiplying.