DIY Heat treating oven help needed

So I found a doc that explains what was probably already explained here and implemented in the doc. from Dan here BUT this one I can understand.. haha. If I make 2 zones, each 3000watts, it would go as so:

14G wire (.064) for 19.2ohms, resistance of 0.2123 ohms/ft
L = 19.2ohm / 0.2123 = 90.44 length

Surface area = PI (3.1415) x dia (0.064) x L (90.44) x length of wire in inches (12) = 218.2 square inches

Watts (3000)/ area (218.2square inches) = 13.75 watts per square inch

Current = watt/volt? = 3000/240 = 12.5 Amps


from what I could find, the surface load should be under 17.5watts per square inch? Krugerpottery has an element on their site for 240 at 24 amps, 2880watts 14G at 13W/sq. in. This seems very close and within all parameters. Only difference is I need 3/4" OD for the wire to fit in the available space.

Seems to be an actual step forward! What do you guys think?
 
351701887_1302845333656155_1839995189976136629_n.jpg
352129994_1391585075049693_1232997881956576595_n.jpg
351565568_824673855919980_2738343370952239215_n.jpg


Work has started on fitting things! I have 0 experience with grouting bricks together.. this stuff is super weird. Since the bricks are so light/brittle it's hard to tell if the joints are solid or not. Every piece has had at least one joint just pop open when handling them that I had to reglue. I read somewhere you should use a sponge to wet the brick faces before putting the grout? Anyways, things are looking good now.
 
PandaRen said:
So I found a doc that explains what was probably already explained here and implemented in the doc. from Dan here BUT this one I can understand.. haha. If I make 2 zones, each 3000watts, it would go as so:

14G wire (.064) for 19.2ohms, resistance of 0.2123 ohms/ft
L = 19.2ohm / 0.2123 = 90.44 length

Surface area = PI (3.1415) x dia (0.064) x L (90.44) x length of wire in inches (12) = 218.2 square inches

Watts (3000)/ area (218.2square inches) = 13.75 watts per square inch

Current = watt/volt? = 3000/240 = 12.5 Amps


from what I could find, the surface load should be under 17.5watts per square inch? Krugerpottery has an element on their site for 240 at 24 amps, 2880watts 14G at 13W/sq. in. This seems very close and within all parameters. Only difference is I need 3/4" OD for the wire to fit in the available space.

Seems to be an actual step forward! What do you guys think?
Click to expand...
I get the same values for resistance, length and surface load. The Kanthal handbook shows recommended surface loads of 20-60W/in^2 for a coil supported by a smooth ceramic rod. For a loosely suspended coil, they show 20-25W/in^2 for the max. loading. You should be okay with the parameters you picked even if you use rods that are a good bit smaller than the coil ID.

The build looks good.
 
Didn't expect the rod diameter fit to affect the parameters. Has to do with surface contact on the wire affecting energy transfer? I can't make sense of most of the kanthal handbook sadly...

Now I have to find a place to get the rods for a decent price. Cheapest I found so far was Duralite at about 8.40$ USD a rod by cutting 24" down (1/2" x 8") but they don't seem to ship to Canada.. Macmastercarr is almost double that... Ebay has nothing.

Thanks for the link, I've already been looking at PSH and will probably order a few parts on there. The 8" kiln posts would be perfect if they weren't 1 3/4" big -_-
 
351628673_231398163091548_5421767407301227507_n.jpg
351483170_259650073324674_8573964292915936743_n.jpg
351253706_981098643311049_8238157640651770592_n.jpg

Made a plywood box with the inner dimensions to test out how it'll fit when the metal enclosure gets done. Might add a little 1/16 or so because it's super tight and hard to fit in, don't want the bricks to break. The Ceramic fiber boards to have a little give to them, if the brick expands a bit will it be enough or do I need more wiggle room?
 
356820550_944479596629080_2416442804736122906_n.jpg

Received most of the electrical stuff. Did the coils today and it turned out pretty good! the finished OD is .80 as I had nothing to get .75 finished after it unwound a bit. Had some trouble when starting off and had to unwind the whole thing which is why the bottom one seems more beaten up... had to redo it all. I figure it won't affect the end result? They're around 19.2-3 ohms each which is pretty damn good!

I have to build the control box with all the inner works and was wondering what would be a good box. I received one with my order but the size is 12x12x4 which seems pretty big and cumbersome. I'd probably like something more compact. I'll have to get the sheet metal to make the box pretty soon and start fitting all the stuff.

I still haven't found a place to get the rods at a decent price. Found one that was reasonable (Duralite) but haven't had a reply after the quote... Would really like to not have to pay 20USD$ a piece as I need 24. Any leads?
 
So I received the casing metal today and I hoped my stupid idea would work to save some money...

I'm sadly not a welder or have a garage like most here so the less assembling I have to do the better. I took some 14 gauge steel and cut the pieces to total laid-flat dimensions and then cut out the corners and scored everything hoping I could bend it where it has to go. All I have to do is get the corners welded up and it'll be good to go (maybe some legs/a base.. dunno yet). Thing worked! A grinder and a mace haha.

357313819_296747572842185_4729344522879690063_n.jpg
358228640_1053174845649065_6305424422196960384_n.jpg
358635697_251471350974928_7041090483100298189_n.jpg
356963908_3261688234121445_3264565719547505525_n.jpg
357066593_1707731449744191_1222122099116196815_n.jpg
 
So I was leaving my friend's house and there was this old gent outside finishing work on the neighbors' railing. I asked him for fun if he'd be down to do a few welds for me and he said sure go get them and gemme like 40$ so I high tailed it to the shop to pick up the stuff and bring it back lol

357062033_6617488321645742_5527154183435013880_n.jpg
360026132_986750835901954_3088462786710593105_n.jpg
357310151_695503722408147_2027251183905791922_n.jpg


He did some crude stick welding but it's tough and more importantly, everything fits! :D

One problem I just ran into: we have some 30 amps in the panel but the one I found was hooked up to apower box with the tool hard wired into it... the outlets on the 240s are all 20amp that I found :| I'D rather not have to redo the whole math and go down in power on the elements.... so I'll ask the boss tomorrow if it's possible to run a line or I don't know if we can put a plug box besides the power boxes where the tools are plugged? Anybody here know anything on the subject?
 
Would anyone have any information or experience with wiring a 3 zone kiln and/or the Genesis 2.0 / Sentinel SmartTouch? I can't find ANYTHING outside the basic wiring diagram provided:
368626662_796607448872269_7578049994270072472_n.png


I figured I would run the power line to a breaker switch and then I'm not too sure if I go into the transformer and then a splitter?

Also the limit switch has its own port so it doesn't seem to be part of the rest of the circuit?

Where can a fuse be added to protect the board?

I have a 32a main switch/breaker
some terminal blocks
3 SSR (have 6 but using 3 seems doable with a selector switch and contactors?) and heat sinks
24V transformer
1 single fuse block and a double fuse block
1 light/alarm in case it can can be usefull
Selector switch

368583837_671106991281580_130353983954271078_n.jpg


It's a fun challenge but finding 0 clues kind of sucks... I can't find information and Paragon has no diagrams anywhere of their KMT Pros which use the same rebranded board.
 
Interesting build - I've tagged the thread hoping you'll find a good (cheap) source for the rods. Good luck with your build.
 
I received rods a while ago from Aliexpress. Price was around 250CAD for 24 x 14mm rod 8" long. Still more than I wanted to pay but couldn't find anything else even near that price

369009922_1901441826891722_8661656386508473067_n.jpg


369003920_1045969126393892_1512220444668737999_n.jpg


Worked on it some more today:
369009922_6869815316363959_6643327425685872437_n.jpg


Of course this is assembled just for looks as the control box has no wiring in it for now... Just the heat sink with SSR and panel + breaker switch to make sure everything fits well. Still need to figure out the proper wiring :/
 
That is one professional looking oven. Congrats on a job well done- OR, it will be when you finish.

Agreed, sure wish those rods weren't so expensive, but gotten pay what's required.
 
Those look like they would work good. Since that vendor seems to be a manuf'ing place not sure how well an order for 100 would go. Shipping might be outlandish. I have requested a quote for 100 pieces of 12mmX250mm rods. Let's see what happens.
 
I have had good luck with Chinese manufacturers on Alibaba and etsy. There may be longer shipping, but it wasn't crazy. The ones I dealt with on ceramic tubes for TCs was willing to do a 20 tube order.
 
Ken H> said:
Those look like they would work good. Since that vendor seems to be a manuf'ing place not sure how well an order for 100 would go. Shipping might be outlandish. I have requested a quote for 100 pieces of 12mmX250mm rods. Let's see what happens.
Click to expand...
They have the required length, what if we mount them lengthwise on kiln roof ? Easier to arrange coils and both ends of the element would be back, where should they be ? Would they hold ?
 
Length wise would mean that you would need to groove out the roof bricks so the coils and rods are in them like when they're in the walls) and they would need to be inserter in a piece at the front and lay on the back wall. Thought about it but that makes for some LONG rods in my case (38") and would need 4 of them.

I just followed JTknives JTknives design mostly and chamber recommendations from Stacy E. Apelt - Bladesmith Stacy E. Apelt - Bladesmith I believe for the 7 x 5. I'm probably going to build a size replica of this one when it's down but MUCH SIMPLER: one T.C. with normal PID from Auber for something with less bang (4200w 17.5 amps-ish) and to be used as a tempering oven for the long blades. Not sure if I'll go top coils again or sides. I might try the top again but less rods (2 per brick instead of 3 so 16 coils total instead of 23) and have them recessed in the top instead of completely IN the chamber.

Speaking of chamber, I've tried looking into this: can you put blades FLAT in the oven? do they HAVE to be edge up? I have about 4" and a bit of height clearance because of the coils which is fine for what I want to do but if I ever wanted to do something bigger or more curved, could I lay it down on a horizontal rack for the heat treat? I got 7' across which could fit most things outside of a buster sword. Is there a distance you want to keep from the coils with whatever you insert in them?
 
I got quotes back from 3 different vendors - seems like the price varies a good bit. None quote shipping costs which can be a game changer. The request was for 100 pieces of 12mmX250mm rods. Prices quoted was 50¢/piece, $3USD/piece, and $8USD/piece.

I wonder if less than 100 pieces could be ordered, but even if 100 pieces where ordered that's only $50 USD - plus shipping. This quote is from "HUTO Ceramic MgO Magnesia tube factory Ceramic Insulating MgO Tube"

I'm not really in the market, I've got a decent EvenHeat 18" oven.

Just got another quote, "for this size, the exworks price is USD1.85/pc, mold charge is USD150" - note the mold charge of $150 USD.
 
Damn at 50$ it's a sweet deal. I had quotes from 150$ to like 3000$ from US vendors... even with 50$ shipping charges it's 100$ which is more than acceptable. for enough rods to last a lifetime.
 
You must log in or register to reply here.
Back
Top