Burned Out Resistor?

[RocketMagnet]

I think I've burned out one of the resistors on my Orion. It's not the PID tune as it's at 100% power but raising very slowly.

Anyway I've got a couple of spare resistors and measuring over two of my spares I'm getting about 3.5 Ohms combined (~7 over one resistor on it's own) but measuring from crimp to crimp on my Orion I'm reading ~8.6 Ohms... the thermistor looks secure so do the Ohm readings confirm one of the resistors is burned out?
Looking at mine closely I can basically see through a hole in the sealant to the resistor on one side so gets me thinking this could be the root cause if one of my resistors has failed?

Any tips on how you get that Orange sealant stuff out, clearly you'll have to clean it all out thoroughly... Any Solvents it's soluble in?

Looks like a real pain to sort out so I may just go for an E3D and avoid the hassle of the Sealant stuff.. if so can I use the Orion standard adaptor plate to mount it
as if I've got to print it I obviously can't....

Also is this the same stuff or comparable as used on the hot end...
http://www.halfords.com/motoring/paints ... er-sealant#[object Object]

[Mac The Knife]

The link you provided is the same stuff. For cleaning out the old sealant, I just run a 5/16" drill bit through the hole. I replaced my resistors with 12volt, 40 watt, 6x20 mm ceramic heaters. One of those will replace both resistors.

[JFettig]

Mac - 5/16" is way too big, its either 6mm or 1/4".

[Mac The Knife]

I'm pretty sure I had to use 5/16 on mine, 6mm is to small for the stock hotend, as shown by geneb's video where he's wrapping a 6mm cartridge with aluminum foil to get it up to size,

[youtube]http://www.youtube.com/watch?v=xvXKt3xDt4E[/youtube]

[Mac The Knife]

Instead of a 5/16 drill bit, use one that is a tad larger then 6mm, 5/16 is to large.

[geneb]

If you use the drill bit to clean the holes out, TWIST IT WITH YOUR FINGERS, NOT A DRILL! Unless you've got servo operated hands, you'll eat the hot end if you do it just a little bit wrong.

g.

[RocketMagnet]

Thanks for the input... I've got it all to bits and the resistors came out easily with one side coming out pretty clean I just pulled out by hand and the RTV just crumbled.
Had to persuade the other side... but still pretty easy job.
I've decided just to fix my current hot end, I may go cartridge heater in the future or E3DV6 but fixing what I've got looks simple enough... hopefully I wont end up blowing my Rambo fuse or something else

Both resistors I've removed look chewed up, is this deliberate in house to help the RTV stick to the resistor or is it heat damage?

The upper resistor is indeed totally dead with the lower one working but reading higher Ohms than my spares, I also managed to kill my Thermistor (snapped the wire.. yeah fixable but the wires look in poor condition anyway) so I've ordered one of these from the UK as I'm in the UK and it's 3 weeks from the US.
http://www.ebay.co.uk/itm/221613016131? ... EBIDX%3AIT
Looks like i'll have to protect the shrink tube bits with Kapton..

One thing I can't find are the Non insulated Crimps in the UK, I can only find the spade type.... the ones on there will last another crimping but in the future I'll need some replacements... can't see any on the SeeMeCNC site and was wanting to order some when I buy some more resistors and other spare parts while I was at it.

[Mac The Knife]

Here are some insulated butt connecters, just strip the insulation off. I'm not sure on the color code, Blue ones may be the right size. http://www.amazon.co.uk/BLUE-BUTT-TERMI ... uto_text_y

[RocketMagnet]

Anyone know what amp rating the extruder wire is please?

Considering this as I'm making up a new loom:
http://www.ebay.co.uk/itm/High-Temperat ... 0988618670
But I seem to recall that the rating fro the cable is much higher than this?

[teoman]

Others will correct me if i am wrong, but in the rostock i remember it as being 22 AWG.


Also, if you get a heated cartridge it also comes with plenty of that wire.


I was reading this thread the other day, and presto bingo, my extruder would not heat above 157 degs. I knew it was a bad resistor, so i decided to upgrade the thermistor and the resistor. I was never happy with the RTV application, in my opinion it is the only really cheesy part of the printer.


First part was removing the hotend.
I was lazy and i did not remove the filament, so just after removing the bowden tube, i cut the filament with a pair fo scissors.

Hot End Removed

The hotend is well used and a bit covered with burnt filament.

Well used hotend

The resistors were fairly crumbly, and they were no longer surrounded with soft reddish RTV but rather a crumbly black substance.

Resistors

My old thermistor popped out rather nicely, and i decided to bag it and save it for a rainy day.

Old Thermistor

Then i used my hands and my nails to clean the hotend, rtv was rater easy to remove as it just crumbled off.

Cleaned hotend

I then used a m3 tap to tap the hole for the thermistor, the hole did not need to be enlarged. I made the handle for the m3 tap myself.

M3 thermistor

The hole in the aluminium in the hotend is not quite deep enough, so the resistor ended up prodruding slightly. But as it is a metal to metal connection i think that it should be ok. If anyone has bright ideas to remedy this i am all ears.

Thermistor in place

I then installed the provided connector the wires.

Connectors installed

Finally, i routed the wires through holes in the hotend. I did not use the groove to ziptie them to the side, i think that this makes a tidier setup.

Updated hotend top

Updated hotend bottom

I later updated the firmware to accomodate the resistor. The setting is provided in another thread that along with the link for the m3 thermistor.

And all is good with the world again

[teoman]

OH ONE VERY IMPORTANT THING!

My peek fan was full of dust and crap, if you read this have a look at it and clean it. It could get expensive if it stops.

[RocketMagnet]

Not thought it through yet but considering running 2X thermistors to the hot end and having a shutdown state with say 10 DegC differential between the two..
OR I may just attach it above the peek and check for too high a temp... and shut down or bleep the buzzer... this sounds good as it covers failed fan scenario also.
Presume this has already been done and I hear that 0.92 does have protection in the firmware.. either way doubling up looks simple?
I've bought a couple new thermistors anyway.. cheap enough..

Not sure what gauge those cables are I linked.. but the crimps on the orion are 18-22 so I was thinking it was 18 but that must be the resistor side of the crimp then..

I've got as modified peek fan holder with a grille on it to prevent it sucking in plastic strings.. seems to work ok.. i've got a few spares

[TFMike]

[quote="RocketMagnet"

Any tips on how you get that Orange sealant stuff out, clearly you'll have to clean it all out thoroughly... Any Solvents it's soluble in?

[object Object][/quote]

Soak it in Mineral Spirits, it will turn rubbery and gooey and should come out easily with a toothpick.

[Eaglezsoar]

Good job in getting the old resistors out and the new cartridge put in. These cartridges work great and don't require that orange RTV.
Nice cleaner look and function.

[RocketMagnet]

Well managed to get it all done and made up a new wiring loom which was both easier and harder than I was expecting.

Below is the list of things I used all sourced within the UK - I picked suppliers based on if they used Royal Mail as it was generally next day or +1.

Got a real find with this wiring for the Nozzle heaters, it's very nice double insulated stuff... the outer coating is only 200 DegC
but it's very impressive and much better than the standard wire IMO.
http://www.ebay.co.uk/itm/High-Temperat ... 0988618670
It's available elsewhere in other colours also.

I cut the insulation off these crimps:
http://www.ebay.co.uk/itm/121163030670

I used these pre made up thermistor cables (which agree within 0.1 DegC of the original at room temp). So much better than messing around trying to solder or crimp the tiny gauge thermistor wire to another wire.... Not sure how it compares at 230 DegC but seem ok.
http://www.ebay.co.uk/itm/221613016131

I used this sleeving which wasn't too bad, much better than most stuff I've had.
http://www.ebay.co.uk/itm/120907095153

I used this RTV Gasket maker for the hot end:
http://www.halfords.com/motoring/paints ... er-sealant

This PTFE tube for the filament (they also supply Propanone (Acetone) few places in the UK will sell you it due to it's alternate uses):
http://www.ebay.co.uk/itm/191086004557

This Kapton Tape:
http://www.ebay.co.uk/itm/370924863942
http://www.ebay.co.uk/itm/370924863942

I think its these JST connector's I used for the hot end fans and lighting:
http://www.ebay.co.uk/itm/Battery-Plug- ... 1202023760

Not sure where I got the wire for the fans but its 26 gauge soft silicone stuff...

Surprisingly it all worked first time and nothing blew up
Main issue was a bit of white smoke from the resistors on first couple of heating cycles. Next time my resistors die i'll change to heater cartridge possibly try E3DV6.
Either way going to make a spare inc loom/hot end I can just swap out when the resistors do die... with the white smoke initially I'm wondering if I've messed up with the RTV
any maybe there are some air pockets and my resistors will have a short life. I was careful and took my time .. sure I packed it all out well but maybe not..

Also the PID tune isn't very good yet, P and D look spot on (in Repetier Host) but I need some manual tweaking outside of the MatterControl auto tune for I.

[RocketMagnet]

Not had much time since my rebuild but turns out I was incorrect about the Thermistor Type for the following thermistor
http://www.ebay.co.uk/itm/221613016131

Type 97 was reading much lower than actual as clearly it was running hotter than it was reading (I'd say reading 10 Dec+ lower than actual)... anyway I managed to identify the actual thermistor used most probably as
100K ohm B57560G104F EPCOS Thermistor

Setting it to type 1 in Configuration.h which is remarked as "1 is 100k thermistor (Epcos B57560G0107F000 - RepRap-Fab.org and many other)" fixed the issue for me.

[Eaglezsoar]

Not had much time since my rebuild but turns out I was incorrect about the Thermistor Type for the following thermistor
http://www.ebay.co.uk/itm/221613016131

Type 97 was reading much lower than actual as clearly it was running hotter than it was reading (I'd say reading 10 Dec+ lower than actual)... anyway I managed to identify the actual thermistor used most probably as
100K ohm B57560G104F EPCOS Thermistor

Setting it to type 1 in Configuration.h which is remarked as "1 is 100k thermistor (Epcos B57560G0107F000 - RepRap-Fab.org and many other)" fixed the issue for me.

Good job fixing the problem!