Induction brass annealer redux

[GrocMax]

Ahhh.......the stink of machining acetal in the morning, the stench of victory.

 

[SGK]

Apparently Delrin/acetal machines more easily than UHMW but I have zippo actual experience with it

 

[SGK]

A preview (5x5cm)

 

[SGK]

The Delrin machined very easily. Aggressive feed with lots of pecking. Nice smooth holes.

 

[SGK]

How are you guys mounting the water pump? Not sure what the rubber mat thing is good for. Also, what coolant are you using?

 

[GrocMax]

Automotive coolant works fine, no need to get fancy.

 

[Gina1]

I've built two units, and have not had any problems with the rubber mat holding the pump/tank. If your concerned about the mat not holding, you could put a small drop of super glue between the side of the tank and rubber mat.

 

[SGK]

So you tossed the rubber dish thing with the big hole in it and just used the double-sided sticky pad to just anchor it down?

 

[Gina1]

So you tossed the rubber dish thing with the big hole in it and just used the double-sided sticky pad to just anchor it down?

No.. I screwed the rubber tank holder to the wooden chassis, and inserted the tank/pump into it. The rubber holds the tank in place, even turning it upside down, or sideways, it kept the tank/pump in place.

 

[SGK]

ok...

Wow, I'm surprised to see the little Uxcell JF-0730B solenoid pulls 1.3A (12V). Did anyone limit the current with a further resistor? I'm aways from setting up the timer but out of interest how long do you guys have the trap door held open for?

 

[ottsm]

ok...

Wow, I'm surprised to see the little Uxcell JF-0730B solenoid pulls 1.3A (12V). Did anyone limit the current with a further resistor? I'm aways from setting up the timer but out of interest how long do you guys have the trap door held open for?

I think it is 300mA versus 1.3A.

 

[SGK]

Nope. 1.3A according to my bench power supply. Actually 1.35A.

 

[McHaggis]

I think I have my time set around 0.3 - 0.5.

 

[Gina1]

Nope. 1.3A according to my bench power supply. Actually 1.35A.

Interesting.. spec's say 300ma. . I set my time to drop a case to .5 sec. Interestingly one builder used a 24 volt solenoid for the trap door and used the 48 volts from the annealing PS.
Because the duty cycle of the trap door is so small, compared to the cover all annealing cycle. The solenoid worked just fine and never over heated.
Gina

 

[SGK]

The only spec listed on Amazon (where I purchased it from) is 1A. I thought it Was a typo - until I put it through a few tests. Initially I had my power supply current limited at a low level and it didn’t work. I became more intrigued to see just how much it would demand when not limited. It got rather warm with some rapid fire testing of my trapdoor.

It will be quite a transient test of the 3A 12v supply...

 

[SGK]

Hmm. Seems I bought a bigger model even though it has the same part number:

https://www.amazon.com/dp/B01B7F61CM/?tag=accuratescom-20

 

[GrocMax]

30-60 ohm coil should be adequate, no need for a 10 ohm coil.

 

[SGK]

Yeah I’m rather annoyed Uxcell is selling rather wildly different parts under the same part number. Search Amazon for JF-0730B and the “1A” version is top of the search list. Mine came with no markings at all and so I didn’t even notice until I connected it to a current limited power supply. I think I am going to try to send it back in exchange for the 300mA one.

 

[Gina1]

Never had a problem returning anything to Amazon. System is automated.

 

[McHaggis]

Here are the pics of inside the PC case Gina. Hope it helps someone like all the pics here helped me.
It’s a bit of a mess in there but it seems to work just fine.