Hot End Electronics Blues - Drive hardware changes

[JohnStack]

Without going into the cause, I'm back to taking the hot end off - which I did and then tried rebuilding - which caused thermistor problems - which caused a short which takes me to def0 and bdef0 indicators on my LCD....

I dry tested the hot end before putting it on and crimping the connectors. It came up to temp just fine. Ready to crimp and go! Right... def0/bdef0 - indicating either a short or something worse.

Anyway, I'd like to see a couple of changes in hardware:

Instead of 2" 6/32 Philips head screws on the hot end and the end stop screws, how about hex heads?

Why? You don't strip hex heads and they're easier to handle.

Screw-in Theremistors

I've already whined about thermistors to the three folks I know who are making them. I'm very over that problem...

Jonesing to print...oh well, lotso parts coming in today and tomorrow. I should have been patient. LOL

[Edit: Broken lead on the thermistor - again]

[Flateric]

You are aware of the screw in thermistors from RP-one labs right? I use them now exclusively and they are really great.

[JohnStack]

Exhale...Saw them. Yup. Not a machinist...lol

My wife is beginning to think I have a girl on the side. I call her Gretel Rostock. Our meeting place is Harbor Freight.

[foshon]

Exhale...Saw them. Yup. Not a machinist...lol

My wife is beginning to think I have a girl on the side. I call her Gretel Rostock. Our meeting place is Harbor Freight.

Tapping is as easy as pi, start it square, turn slowly, at the first sign of a change in the resistance back it up out and clean the chips. I am about as bad as it comes when it comes to hand machining, give me a machine hooked to a computer any day of the week. Tapping however, is very easy.

[geneb]

I'll second this. Unless you're a Fischer-Price tool user from NZ, you should have ZERO problems tapping the stock head with an M3 tap.

g.

[JohnStack]

Ok, I'll do it next round.

So now the question is - instead of sourcing these and having a delay - perhaps you build up a few in advance.

So sourcing the M3 brass fittings - anyone?

Use Arctic silver as suggested in and around this forum?

The leads are so tiny - so I like soldering on extensions and shrinking on some tubing. Anything else?

[@Geneb, I'm having Fischer Price tool separation anxiety.

[geneb]

The brass fitting is simply an M3 male/female hex standoff. I don't know that Arctic Silver is an adhesive. Is it?

As brittle as the leads become when you solder them, I'd really recommend going to a craft store and buy some crimp tubes of a diameter sufficient to handle the wire gauge you're using to connect to the thermistor leads.

Something like this may work for you: http://www.digikey.com/product-search/e ... vendor=952

I'm sure they can be had cheaper, but that's what came up quickly.

g.

[lordbinky]

Artic Silver thermal paste is not an adhesive, just a good filler for thermal transfer. In theory a thermal paste would give more consistency to a thermistor if that was filling the area directly around the thermistor, then RTV behind that to actually plug and secure the thermistor in place. If using you do go with adding a dab of thermal paste, do a sanity check (ie quickly google it) on the operating specs for that specific type since they do vary significantly.

As for the screw in thermistors, I far as I can tell these are simply General Electric Type M6000 sensors. It doesn't offer a pricing and wants to to ask for a quote, I assume it's since it is dependent on so many variables that some/all parts are made to order. I haven't felt like placing a quote for 10 to see what it would cost, since sometimes made to order stuff costs the same for 10 pieces as 100 pieces. That and my curiosity wasn't strong enough to overcome the fact that I couldn't use them right now *cough* LAZY*Cough*

http://www.ge-mcs.com/en/temperature/in ... m6000.html

[geneb]

While what we're talking about LOOKS like the GE parts, they're not at all. They're simply M3 M/F standoffs with a thermistor glued into the female end of the standoff.

g.

[lordbinky]

I will now think on this, thanks.

[foshon]

While what we're talking about LOOKS like the GE parts, they're not at all. They're simply M3 M/F standoffs with a thermistor glued into the female end of the standoff.

g.

As in motherboard standoffs?

[JohnStack]

Isn't that supposed to be a purple comment?

[kbob]

What is the advantage of the screw-in thermistor?

[cpunches]

For me it's a consistent fit on the thermistor. I had a hard time on my original hotend getting the thermistor to stay put while the silicone cured and had even more trouble with the leads breaking and/or the solder joints from the leads to the wires breaking. Once I tapped the holes for the screw in thermistor I'm done, also I can remove it easily if I want to install it in another hotend.

[foshon]

Isn't that supposed to be a purple comment?

No, I don't think so. Maybe a stupid question though. I have close to a hundred of these laying around, just thought I could roll my own.

[Eaglezsoar]

You can certainly roll your own. Use the Arctic Alumina Thermal Adhesive (epoxy) to glue in the thermistor and you have what they are selling.
Sorry, it doesn't come in purple. Before gluing I would put the small UHMW tubing for the wires on and make sure they also end up in the epoxy
so that they cannot come off or move up. McMaster Carr sells the female standoff with the 3mm male thread just in case someone wants to
roll their own.