Bits and pieces

I'm nearing the end of my build now and I need to acquire a few last difficult-to-locate items, anyone know where to source these locally before I go and mail order them in?

- Kapton tape
- PTFE tape
- Fire cement (I picked up some Araldite glue from Bunnings, can that withstand the high extruder temps?)
- The M4 insert for the extruder (do model stores sell these?)

Check the Aus Suppliers page on the wiki.

Ultrakeet sell Kapton.

For plain PTFE tape I'd suggest any plumbing store. Best to get stuff rated for use with Gas pipes (it's only a few cents dearer), as it tends to have a higher temp rating.

As for fire cement, I found a place near me called Pennhaulricks (it's a hardware store, near the corner of Hawthorn and Glen Huntly Rds.) that has stuff called Fireup Pyrogrip, which I haven't seen in other hardware stores. It's a Sodium Silicate based adhesive, so heat is no problem. Anything that is good for Fibreglass rope or firerope is good, whereas high-temp RTV silicones aren't so great. Also, unlike traditional fire cement (eg: Selleys Fireproof) it doesn't tend to crumble as much after it sets.

BTW: If you do find some Rope Glass type adhesive (almost pure Sodium Silicate), then it's probably the best stuff to buy. I've not found anywhere in Aus that sells it yet.

PS: Wear gloves and goggles with Sodium Silicate based adhesives. You don't want to get it on your skin, as it'll itch a lot afterwards, or if you get enough into your system (inhale/ingest), you could get silicosis.

Hi,

Google only lists local supplier catalogue PDFs of Heating Melbourne and SDBerg (either same company or SDBerg is supplier to the other). I can't see the item on their websites but it is on page 27 of the Melbourne Heating catalogue PDF and page 23 of the SDBerg catalogue. Let us know if they have some, and the ballpark price please :-)

[www.heatingmelbourne.com.au]

[www.sdberg.com.au]

Seeya,
Scott

What about J-B Weld? Not resilient enough? If it is, there's some allegedly at Jaycar... I'll go have a look too.

Seeya,
Scott

I've not used JB Weld. Some people in the US use it. I personally don't think it'll have an appropriate upper limit for an extruder.

This stuff will surround the barrel and the heater element. I would not be surprised if it will get over 260 Deg C, and if you have an extruder issue, something like 280 could be possible.

I don't know at what temperature JB Weld decompose, but most RTV silicones decompose around the 260-280 mark.

BTW: I think a 400 Gram tube of Pyrogrip (ie: you need a caulk/silicone gun to push it out) costs about $20. They have a place on the shelf for a 200 gram tube, but I've never seen it. Also note that I've only seen one other tube of Pyrogrip on the shelf after I bought mine (as of last week - and I've had mine for about 3 months). I have no idea if they're going to buy more. Admittedly, I have heaps left (400 grams is quite a lot), so for those going to the meet-up, I can always let you use some if you bring your extruder over.

Nophead posted about JB Weld here:

[hydraraptor.blogspot.com]

Quote
nophead
Hi Giles, Bad news about the glue. What is it about these high temperature glues? I found out why JB-Weld is no good: The max temperature rating is only for 10 minutes!

> for
> those going to the meet-up, I can always let you
> use some if you bring your extruder over.

Thanks Cefiar, I might just take you up on that if I haven't managed to pick some up by then.

I think I've come up with a great replacement for the insert too, which I suspect may work even better. I'll post a photo or two tonight.

Hi..

I have been using this. Cost $10.00 a tube
[pivotonline.com.au]
They do mail order..

Auzze

Auzze; Interested in seeing what it looks like. Can you bring along the remains of a tube and something you've used it on so we can compare it?

Here's my attempt at a replacement M4 insert. Basically I'm stealing the labitat team's idea of attacking a couple of M4 nylocs with a Dremel:



Their photo looks pretty rough-as-guts though, so what I've done is basically the same thing but using a spherical carbide tip instead. This causes the metal to fuse and you get a much nicer result:



I've also super-glued a piece of shrink-wrap around this, the idea is to create something with a much higher contact surface area that snugly wraps around the plastic filament instead of just pressing a few metal gears up against it. In theory this should result in much better grip:



The potential problem with this is if the shrink-wrap isn't up to the job and quickly disintegrates due to the continual force of driving plastic filament through the extruder. Replacing it would be a fairly trivial task, so I guess the question is going to be whether it holds itself together long enough and performs well enough to make it worthwhile. The nylocs alone might be enough to do the job in combination with spring-loading, or there might be a material that's more suitable than shrink-wrap. Either way, I think this piece is going to be a lot easier to source than the standard M4 insert.

Edited 1 time(s). Last edit at 02/03/2011 07:28AM by Myndale.

the metal teeth are meant to be pretty small so they can dig into the plastic, the springs force the filament onto the teeth and this creates a considerable amount of force

Thanks again for the tips everyone. For anyone that wants to do a google search for the place that Cefiar mentioned the correct spelling is "Penhalluriacks" and their contact details are here:

[www.womow.com.au]

According to my fiancée the guy that owns the store was famous in the 90's for going to jail for Sunday-trading back when it was illegal...what a legend I popped in today (a Sunday) and they still sell Fireup Pyrogrip but it wasn't on the shelf, they only had them out back. Also they only had the 500g tubes for $20, which was a bit of overkill given that I only need about 2 drops of it. I know I could have counted on you for some Cefiar, but being this close to the end of my build I'm getting impatient

One of the things I didn't mention was springs for the extruder. The guy behind the counter at Metro Bolts in Richmond suggested I use springs from ball-point pens but they're just a bit too small for M4 bolts. Bunnings sell them though, look for "Utility Comp Spring C-582" in aisle 38 which are 3/16 inches wide. I also picked up some C-608's which are larger and exert considerably stronger force.

PTFE tape I was able to acquire from Reese plumbing. The guy didn't know what I was talking about until I called it "Teflon tape...for gas pipes" but he was nice enough to give it to me for free. I also picked up some blue Scotch painters tape from Bunnings for printing on.

The only thing holding me up now is the Kapton tape which I spent all weekend trying to source locally to no avail; looks like I'll have to order it in from Ultrakeet. I guess I also need to start thinking about getting some plastic rod, do you still have some available Cefiar? And is it ABS or PLA?

Edited 1 time(s). Last edit at 02/06/2011 07:50AM by Myndale.

Yeah sorry for the spelling.

I have some 1m sample ABS pieces from Lybnia you're welcome to, and I still have some PLA. It's mainly for my own uses, but you can bargain with me on the day of the Meet-up (depends if I still have excess left by then).

Note: I know that Auzze and someone else are buying some in PLA from Vik Olliver in NZ. You may be able to negotiate with them to buy a roll off them to get you started.

On the day of the meet-up, I think one of the things we should chat about is bringing in bulk lots of PLA from Vik and/or getting Lybnia to make them. Lybnia's quality for ABS is good, but if he extrudes PLA it'll all be one colour in some large amount, whereas with Vik we can get lots of smaller amounts in varying colours. That said, if there is enough demand, there is no reason we can't do both, especially if Lybnia turn out to be cheaper.