coen-lab / chronic-neuropixels Goto Github PK

Hi everyone,

We've since found a workaround, but I'm posting here anyway in case it helps someone:

We've been having problems with heat-inserting threaded inserts in the docking holder for the NP1 probe. Basically the walls of the insert-hole kept cracking when we tried to insert the metal parts.

This was particularly a problem because we can currently not print resin parts in the lab, and our printing service is quite expensive.

Initially we used threaded inserts for M3 screws that had a 5mm outer diameter. These completely destroyed the plastic when inserted.
We then switched to the M2.5 threaded inserts from CNCkitchen, which have a 4.6mm outer diameter and are 4mm long. These inserts fit much better, but still cracked the plastic (see pictures). And you can see that there is very little melting around the metal parts.

So, wondering if everything I thought I knew about plastic was wrong, I then tried to melt one of our broken docking holders with a hot soldering iron. I could not. The hole-walls remained solid for a long time and at the point where the plastic became somewhat flexible it just lost structural integrity and cracked/tore in a similar way that happened with our inserts.
I think this is because resin is not a thermoplast (at least our printed resin does not act as a thermoplast). I was able to make a small scorch mark with a very hot soldering iron (approx 400C), but there was no melting.
EDIT27/5/24: We asked the company to print in PA12 nylon, but they ended up printing everything in resin for us. I'm not sure how that decision was made precisely, but I don't recommend it for other users. I can't find the precise type of resin they used.

We ended up just gluing/reinforcing the cracks in our best docking holder with some 5-minute epoxy and this seems to hold up fine for now.

Of note:
We were able to insert the larger inserts in the payload holder just fine. Similarly, we're able to insert the tiny inserts in the payload module without too much trouble. I think the larger/wider amount of plastic around the holes keeps things from cracking.

Best,
Susan

Thank you for sharing this wonderful design.

However, I am a bit confused about how to assemble the NP2_SingleProbeMiniature.
Following the instruction, the probe should be attached to the probe side, but it's too narrow for the probe and almost all the shank will be hidden inside the payload and docking.
On the contrary, looks like the head stage side fits the NP2 so well, however, there is no space in the docking for the shanks.

Is it possible to have more clear pictures of the step-by-step ensemble process? Also, it would be great to show how the flex cable is folded when connecting to the headstage.

Not only for the miniature design, it would be great to have more pictures of how to place the headstage and flex cable using NP1_HeadstageHolder_top & NP2-Alpha_HeadstageHolder_top design.
Thank you so much!

Hello,

Our local Czech WPI distributor does not sell Kwik-cast or Kwik-sil.
Do you think we can use SmoothOn Body Double as an alternative for filling the gap at the bottom of the docking module?
We've also considered using wax instead, but personally I worry about getting it on the probe and blocking all the contacts. Any ideas?

Thanks,
Susan

Sorry for the naive question, but what's the details of "heat-inserted"?
[M1 Brass knurled inserts]: To be heat-inserted into the Payload.

What's the recommended temperature, and what's the procedure?

Many thanks!