Reflow Toaster oven for VHS

Continuing the discussion from Solder Paste dispenser - Call for donations:

I’m looking for a project so I’ll take this on. I’ll build the controller. @Gonazar, can I count on your $20 towards the parts?

Anybody else interested in participating?

I’ll start with a design and parts list.

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@hectorh
I’ll drop the oven off this weekend (or shoot me a note when you know you will be at the Space)
I also have some welders blanket (woven fiberglass) that you can use to insulate it…

Ah so you’ll be building from scratch? I’d be interested in helping with the build too.

Damn, this is exciting. We may have a fully equipped SMD station very soon.

Continuing the discussion from Solder Paste dispenser - Call for donations:

COOL! Thanks!

All great feedback and will do something similar. What temperature did you use for your thermal cutout line? Where did you get it?

I think the thermal cutout was 100 C (it’s in the area on the right side of the oven behind the controls, not the oven chamber) and I got it at Lees…
I may have another one , I’ll take a look…

Bump.

Could we hack together our own kit using a SSR, Arduino and thermocouple?

It should just be a PID type controller to follow a preset curve right?

Yes, that’s what I’m doing. I got the parts in now, going to find some time to assemble it in the next week or so.

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Let me know when, I can lend a hand if I’m out that way.

I’ll be at the space for the kicad nights and I could probably swing by on Friday nights too.

I do need help with the mechanical stuff ( internal insulation, adding IR reflective tape to the glass door, building a door opening mechanism, replacing the wire tray with an aluminum sheet, etc. ). @packetbob has nice pictures of his oven build. I think he did a great job.

Yeah I can put a couple hours in helping with this.

Might have an idea for insulation. experimenting with VHT paint for my 3d printer. If it works would be good inside the oven. Its a silica embedded paint so might help reflect some heat back in. Will be curing my thermal block tonight see if it does anything to make it better after that.

Also I have experience with thermisters so can help with putting a couple of those in for heat monitoring.

I think the recommended insulation for the reflow toaster oven conversions is the fire-proof blankets used by plumbers.

Such as:

http://www.homedepot.com/p/Oatey-9-in-x-12-in-Hands-Free-Heat-Shield-314002/100345508

http://www.amazon.com/dp/B000FNUFRA

I met Phang from Rocketscream in Shenzhen. Totally awesome guy. He is sending me a pcb, I think for http://www.rocketscream.com/shop/ospid-kit perhaps I could donate it as the basis for this build?

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This one looks pretty nice and the price is decent:

http://www.rocketscream.com/shop/reflow-oven-controller-shield-arduino-compatible

I just checked, this is the pcb he has sent me. Should be here any day. Doco is at http://www.rocketscream.com/blog/portfolio-item/reflow-controller-shield/

  1. I have lots of welder blanket left over from my build (It’s woven fiberglass) so send me the dimensions and I’ll cut up what you need. I found that the edges were a bit of a pain so I “edged” them with Kapton tape to keep it from unraveling…

  2. I will dig up the picture I took during the build and get them online somewhere…

Would you be interested in selling all of it? How much do you have? (I’m building an oven for myself too)

I’m sure I have enough for several ovens…

Yeah I’m kind of interested in building one for myself in the near future too.

Have you made a parts list? What’s the expected total cost?

No complete parts list, but off the top of my head:

  • toaster oven (~$80, donated by @packetbob ) small and with quartz glass heating elements
  • display (going to use one from the bin at VHS)
  • mcu (msp430 as I’m familiar with it and I’m not a fan of the arduino ecosystem)
  • thermocouple (~$8 from ali)
  • thermocouple interface (using MAX6675 as it performs cold junction compensation and the output is digital) (~$6 from ali)
  • SSR (AC, 25Amps, isolated) using one from Ali … (I wonder how safe it is, I’ll know when I power it up)
  • Miscellaneous wiring (going to pick up some high temperature/high amperage) probably around $10
  • Beefy AC cord (from parts bin)
  • fuse (from parts bin)
  • thermal cut-off (re-use oven’s original thermal cut-off)
  • buttons (from parts bin)
  • thermal blanket for insulation (~$20, but @packetbob is donating some from his stock)
  • Reflective foil to reduce thermal mass of the toaster oven ~$20-40
  • Miscellaneous aluminum sheets (~$20)
  • Servo to open door (~$20)

alternatively the reflow oven controller for $38 ( http://www.rocketscream.com/shop/reflow-oven-controller-shield-arduino-compatible ) is very tempting and will save a lot of effort, I just don’t have the funds for it. Tom says he is going to get a sample board, but we will still need to get the chips for it.

Or you can buy a complete kit from Whizoo like @packetbob did ( I think it’s around $180USD)

That reflow controller is really interesting. Since it’s open hardware it’s nice that they uploaded a full schematic, makes me tempted to lay it out on a PCB and fab it myself. It’s probably worth the $56 CAD (incl. shipping) though, it’d likely cost just as much if I made it. If Tom gets the sample then we can definitely source the chips and solder it ourselves. Though you’d have to figure out how to attach the shield to the MSP or find an Arduino somewhere.

Without that shield you still have to put together an equivalent circuit. Were you thinking of doing it all on a protoboard instead?