the reason I say put them lower, is that there will be 2 really big hot spots right over them, and if the top isnt properly insulated those hotspost will transfer a good chunk of heat to the air around them.


Jon

They are Ogden Mighty Watt cartridge heaters #MWFX22-X (special order) left over from a project I did about 10 years ago. 0.25" dia. x 2.0" lg, 150 watt, 32 Volt, 7 ohm

Watlow also makes cartridge heaters - FireRod series. The problem with both of these sources is their stock heaters are designed to operate on 120 V or 240 V. I'm looking back into it - I'll post any findings in the Testing & Benchmarking > The Heat Die thread... :)

I think this is going to work much better,

http://3rotor.homelinux.com/SCM-BB/c...tor/cad_03.jpg

No matter where you place the heaters, temp stability is going to take the same time, as it is needed to heat all that copper mass. The only way to get a faster response time is milling away a big portion of that. Given that fact, it's preferable to have the heaters lower to get a more even heat distribution.

more or less like so...... :)

http://3rotor.homelinux.com/SCM-BB/c...tor/cad_04.jpg

yup

Ok I will be doing this on a proper chunk of cast-iron....

http://3rotor.homelinux.com/images/R...C/DCP05690.JPG

My little press does not have the Hp to do this.

Will have pictures of the prosses shortly.... :)

Now your talking :D


ooh man, I love Bridgeports!


Jon

http://3rotor.homelinux.com/SCM-BB/c...b_dscn5905.jpg
http://3rotor.homelinux.com/SCM-BB/c...b_dscn5906.jpg
http://3rotor.homelinux.com/SCM-BB/c...b_dscn5907.jpg
http://3rotor.homelinux.com/SCM-BB/c...b_dscn5908.jpg


came out pretty damn good, Mind if I say so myself... :D
[edit for bandwidth friendliness :) ]

Some close-ups of the actual retention
 

http://3rotor.homelinux.com/SCM-BB/c...b_dscn5909.jpghttp://3rotor.homelinux.com/SCM-BB/c...b_dscn5910.jpghttp://3rotor.homelinux.com/SCM-BB/c...b_dscn5911.jpghttp://3rotor.homelinux.com/SCM-BB/c...b_dscn5912.jpghttp://3rotor.homelinux.com/SCM-BB/c...b_dscn5913.jpg

2 springs from a couple of dead BIC finepoints, and 2 short pieces of PVC on the back. This is to insure a very snug fit, while protecting the heater cartridge from getting damaged by over tightening.

ut oh, guess what I just observed..... did you notice how those might be obstrocting the mounting hole places... or how do you plan on adapting it for that?


Jon

I am planning on encasing this in a box made of phenolic resin to insulate it when it returns. I was planning on just tapping AMD mounting holes into that.

let me kid no one not.... this is one big chunk of copper.... :D


had it on a 12v car battery here, running the two elements in parallel.... took it about 5 minutes to get up to 55ºC... then I dis-connected, it's now 15 minutes after that, and it's slowly starting to come down.... about 0.1ºC every 10 seconds....

this thing should be awesome for getting some real accurate and extremely stable measurements.....

http://3rotor.homelinux.com/SCM-BB/c...b_dscn5917.jpg

Nope, thought of that even before I got going in AutoCAD

;)