The big ELECTRONICS topic
I’ve been around now for a couple of months and I see a lot of the same questions related to electronics.
In this topic I would like to answer some of these questions.
In general its not complicated to assemble the electronics, just always be careful and don’t to stupid things 😊
The awnsers to the following questions will be in the replys down
– How much energy do the machines consume?
– Schematics for all the machines
– What parts do you need, and where do you buy them
– Tips and tricks
– decapping thermocouple
– wago connectors
– electronics of others
feel free to ask questions or suggestions for things i forgot 🙂
@ollie2019 Yep, you just connect your earth wire to the frame or the box or whatever, but make sure that all accessible elements are grounded by their physical connections, e.g.screws.
@anne-barbier Is there any explication for your statement: “– don’t create multiple ground cables (aka ground loop) along the same conductor (metal frame)” ?
‘Ground loop’ – this is a totally different issue and really not relevant here.
For a start the safety connection is an ‘Earth’, not a ‘Ground’ (the terms are often confused). In normal use there is no current flowing through it, it is only to provide a return path in case of insulation failure, to lessen the chance of electric shock if you happen to be touching a bare metal part. (A ‘ground’ in a circuit provides a return current path in normal operation).
You should connect the earth to any metal part that has live wires going through it or where there is a possibility of it becoming live should a wire become loose or damaged. If multiple metal parts are bolted together it’s not usually necessary to earth every individual one, though there is no problem in doing this (it won’t create ‘loops’), machines often have motors which are earthed and also have a separate earth connection (or more than one) to the chassis. If metal parts are painted before being bolted together this can insulate them from each other so multiple connections are not a bad idea. You do not need to earth metal parts that are insulated from the rest of the machine if they are not near any live wires, eg. a metal handle on the end of a plastic lever.
A ‘ground loop’ only effects sensitive electronic circuits which are susceptible to small changes in supply voltage, such as high gain amplifiers and low current microcontroller circuits. The ground here is always carrying current when the circuit is powered. If you have multiple electronic circuits running from a single power supply, the normal practice is to connect the power connections in a ‘star’, each circuit directly connected to the supply. If you connect them ‘daisy chain’ fashion you create ‘loops’ where the current from each circuit gets added/divided and this causes electrical noise between the circuits, especially if you have a high current or inductive device next to a low power circuit. Much better explanation here: https://en.wikipedia.org/wiki/Ground_loop_(electricity)
i have mentioned the loop thing rather for completeness since it can get an issue in bad environments and/or additional equipment along the machines. I have seen all sorts of weird wirings (parallel ground wires all over the place,..) by newbies and that was the more ‘working’ explanation i had for them 😉 , especially for large chassis/frameworks.
Thanks everyone for all of you help so far!
We have managed to set up the electronics as per the schematics and photos seen in this post. We’re 98% sure we have done it correctly!
However, the bands are not heating when connected to the full circuit. We have tested each individual component and all of them seem to be functioning. We performed a test with a 9 volt battery on each of the SSRs 25DA – both worked and responded to current (light turned on). We connected each heater band directly to 220 and all four worked. The thermocouples are both working and reads the correct temperature on the PID controllers. The REX C100 PID controllers are both turning on and click when trying to reach the SV (we used our body heat to heat the thermocouple). We did a separate test with the battery, the SSRs and the band heaters and that also worked.
We have probably watched every single YouTube video to try and ensure our wiring has been done correctly and there doesn’t seem to be any obvious reason why it shouldn’t work! The current is reaching the PID but isn’t getting transferred into the SSR, meaning the circuit isn’t completed. We think there are two options:
1) The settings on the REX C100 are incorrect (although the audible click when trying to reach SV seems to suggest otherwise??)
2) The PID controllers arrived with the connecting screws in terminals 1, 2, 3 and 4. I moved 3 to 5. I can’t think why this would be a problem but it might be?
Has anyone had any similar experiences? Is there any known programming of the PID that will activate or deactivate the current being passed to the SSR?
Thank you so much!
hey, yeah, after having it done 30+ times this still happens to me as well 😉
however, try :
– flip the upper wires going into the SSR
– flip the lower wires going into the SSR
i assume you got the basics right: one heat band cable goes to the main power supply, and the other one goes into the right upper SSR (labeled ‘2’). the left upper SSR is going to the main power supply. so the relay basically opens/closes the flow between the upper terminals of the SSR.
well, i hope this makes sense 🙂
Sounds like you have the ‘relay’ version of the REX C100 rather than the ‘SSR’ version, can you show us how you’ve connected it? Are you using a DC power source to drive the input of the SSR via the relay? The relay on it’s own is just a switch and won’t do anything without power.
Thank you so much for your help again Anne! I’m glad to hear that even the most experienced have these issues!! We will try these techniques later on this afternoon/or tomorrow. I think we’ve played around with the PID settings so much it would be nice to do some sort of factory reset… Hmm.
Thanks Andy. Yes, we’ll send a photo later/tomorrow too. According to the original item on Ebay, the REXC100 has control for Relay and SSR. Any idea how we’d go about changing this if we needed to?
@ollie2019 There are different types of REX-C100 controllers, check the part number against the manual, eg. REX C100FK02-V is the SSR output, REX C100FK02-M is the relay output. If you have the -M it’s possible to remove the relay, jump the connections for the relay coil straight to the output pins and use this to drive a SSR. There was a tutorial with pictures on the forum a while back, but it’s easy to figure out if you open the unit.
I have problems with the Rex C100Fk02-V*AN. I have conected the chords according to the scematics and i am sure theyre all wired correctly. However, one of the controllers doesnt show any numbers in PV it just shows three squares.
THe other one measures the temperature through the thermocouple and it seems to be working all good but i dont know how to set it up. Ive stared myself blind on the manuals but i just dont get why it isnt working.
I am so sorry for being a newbie, but its really frustrating, i just want to get started extruding.
All the best!
Thanks for your response @anne-barbier, i will do that. Ive done it a couple of times actually but it doesnt hurt to do it again.
Do you or anyone else know how to reset it to factory settings?
Did you change anything after recieving it in order to get it to work?
I pulled this 240v indicator light from the oven I am going to use to build the compression.
Now I want to use this and also have the fan in the oven running when I flip on the switch. Now they both say they run at 240v, still given the amount off electricity on them I am hesitant to connect them.
Would like to hear from someone to confirm how to connect the fan and indicator light, just to be sure.
Thanks so much in advance, once I am certain about this I can start building the electronics in the compression machine!!
How may Watts does the bandheaters need to be? The ones i have ordered are out of stock. They have an alternative, is it o.k.?
3x 923-149 35mm Diameter x 45mm breedte – 220W
3x 923-143: 35mm Diameter x 40mm breedte – 195W
1x 923-179 40mm Diameter x 45mm breedte – 250W
1x 923-173 40mm Diameter x 40mm breedte – 225W
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