Fun with Fixtures

[TomG]

Just to show that it's not all fun and games, I thought I'd share a little fixture that I threw together to modify some parts at work.

We are two weeks out from shipping a brand new product and there was a slight issue with the molded front covers on the instrument. It seems the mechanical design guys didn't leave enough room for paint buildup on the front panel of the instrument and a removable access panel doesn't fit quite right.

The solution is to remove the offending paint on two mating surfaces of this first batch of parts (Luckily the plastic is almost exactly the same color as the paint), then have the mold changed. Since there are fifty pieces to modify and clamping them is kind of like trying to clamp a potato chip, I decided that a fixture would be worthwhile. I milled a key on the bottom of a block of aluminum and added a couple of holes so it could be clamped to the mill table, then milled a bunch of relief cuts to clear all of the features on the underside of the cover and then added a couple of reference edges to locate the part. A few toggle clamps made switching the parts out a cinch.

It ain't pretty but it sure saves a lot of time. I just wanted to bring this up because any time I have to make more than a couple of parts, I always consider investing some time and making a jig or a fixture. It can save a lot of time in the long run and prevent a lot of grief when machining multiple or complex parts.

Tom

[ScrapMetal]

Nice work! Your "fixture" looks better than many of my "finished" projects.

-Ron

[dallen]

thats cause he used them pretty red handled Carr Lane clamps

NIce Work on the fixture

[Tony Wells]

Interesting product line. Are you OEM or subcontractor?

[TomG]

(08-02-2012, 04:59 PM)dallen Wrote: thats cause he used them pretty red handled Carr Lane clamps

NIce Work on the fixture

Thanks Dallen, those clamps are definitely handy little gadgets.

Tom

[TomG]

(08-02-2012, 06:55 PM)Tony Wells Wrote: Interesting product line. Are you OEM or subcontractor?

Hey Tony,

We are the OEM, small business at it's best. We invent, design and build the instruments in house. Then we contract out all of the production machining, sheet metal and boards, then bring it all back in house for assembly and testing. Another big part of our business is service work, where we do drug screening for pharmaceutical companies using our own instruments. Essen Instruments grew from three of us in 2001, through three moves and a name change to Essen BioScience, to 85 people today. It's been a wild ride.

Tom

[Tony Wells]

Yeah, I bet. I did a little reading on the company after picking out the product name on the panel, even though it is upside down. I was involved in a little startup company for a while back in then early 80's where we invented, designed, developed and built complete in house machinery for the polyethylene bag packaging industry. I learned a lot about the molecular structure of PE, and had a blast with the design work. Unfortunately, the main principals were 25 year fishing/beer drinking buddies whose wives got to liking the smell of money and broke the partnership up (my analysis). Sad really. One partner was ruined, and the other still has the business. I believe it is doing OK, but there were several casualties due to unfounded suspicions of disloyalty and paranoia. I was one of them.

[TomG]

I hear ya Tony but luckily there's none of that here. I worked with these guys for years as fellow employees of a DOD contractor before they started their first company so I know them pretty well. I did all the design and fab work for them then as a subcontractor so I missed out when they made it big, but when they started Essen Instruments, I was first on board. It was definitely a tough decision to walk away from the security of 500 employee company to one with three, but I never looked back. Now I get to see these products develop from concept to completion doing mechanical design, prototyping, testing, and even get pulled into manufacturing engineering when they go into production.

There is some talk of bringing on some more mechanical engineering help since there are only two of us and we are both fifty somethings in a company full of twenty and thirty somethings.

Tom

[DaveH]

Tom,
Some smart work - very nice

DaveH