Received an initial drawing and a quote. So far it’s exactly what I designed with the basic tweaks. I have not seen the plan for the inside, which is probably more important.
There is some discussion of using normal M3 nuts in the bottom, but we need to have a meeting about it. Also a friction lock, but I’m totally against that.
What do you think about using normal nuts in a cavity on the bottom, instead of the insert nuts buried inside? I made a version like this previously. Here’s various pros:
- Totally automated injection molding. Faster and cheaper than insert nuts.
- The factory really doesn’t want to do insert nuts because it’s a hassle. I don’t disagree based on our previous experience.
- Bing manages final assembly and he thinks it was easier to assemble this type instead of the insert nuts. However, that is based on the really poorly done insert nuts.
- The insert nuts are prone to pull out if the bolt is tightened too much with production line tools
Cons:
- Feels less professional to me
- One more part to lose
- It’s not that much cheaper, 45 seconds vs 60 seconds a unit
- Properly done insert nuts may be stronger and easier the previously poorly done insert nuts
- Height will have to be adjusted to fit a standard size bolt.
Perhaps with silicone feet covering the nut and cavity? A sort of low rent version of this?
I’m a bit confused why they quoted PP when we’ve been discussing all these LED specialty materials. Something else for the meeting.
Two pieces (top, bottom) go in a single tooling. Tooling steel is S136H and weights 164 pounds (half kilos). There’s some info about injection and cooling methods.
It takes 26 days to do the tooling (this is twice his original estimate). 50% payment up front, 30% at testing, and 20% after test moldings.
Overall a much better experience than the previous factory.
We’ll get this finalized tomorrow.