JHCC Posted February 26, 2017 Share Posted February 26, 2017 I made this gate valve for my new JABOD forge and thought folks might like to see how the insides work. It was pretty easy to put together, and all the materials were screws and pallet wood that I had on hand already. Starting with the back board of the forge, I drilled a 2" diameter hole in the middle. I used a big Forstner bit for all the holes, but since the pallet wood was so hard (red oak), I had to hog most of the material from the middle of each hole with a twist bit. The middle layer has two holes spaced 2" apart: one that directs the blast into the tuyere and one that exhausts the excess air. The sliding gate has a 2" x 4" oval. When the gate is all the way in, the oval connects the blower with the tuyere. When it's pulled out, the oval connects the blower with the exhaust vent. Another piece of wood covers the outside and holds the whole thing together. The 2" hole is centered between the tuyere and the exhaust vent. The little metal clip keeps the gate from pulling out, and there's a little block of wood at the end (see top photo) that keeps it from pushing in too far. Quote Link to comment Share on other sites More sharing options...
JHCC Posted February 26, 2017 Author Share Posted February 26, 2017 It's pretty rough and ready and leaks a lot, but it does a great job of adjusting the blast. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 27, 2017 Share Posted February 27, 2017 Kind of fancy for a box of dirt isn't it? Pretty slick John, the blower inlet is the round hole visible on the outside in the pics. Yes? Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Andrew Martin Posted February 27, 2017 Share Posted February 27, 2017 Wow, my air gate was a slot cut in the tue pipe with a scrap of sheet metal shoved in, way more rough and ready than yours lol. OTOH, you won't lose the gate as many time as I did. Quote Link to comment Share on other sites More sharing options...
JHCC Posted February 27, 2017 Author Share Posted February 27, 2017 47 minutes ago, Frosty said: Kind of fancy for a box of dirt isn't it? Pretty slick John, the blower inlet is the round hole visible on the outside in the pics. Yes? Frosty The Lucky. Yes, that's the inlet. I haven't yet figured out how to attach the blower, but then again, I'm not yet sure what the blower actually will be. I'll probably start off with the same shop vac I was using before, but Lisa just got a new vacuum and I'm all set to modify the old one. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 27, 2017 Share Posted February 27, 2017 Wanna go old timey blacksmitherly? Find a tin can about the right dia to fit whatever blower hose you have. Then find a larger tin can and cut an end out. trace the ID of the small can in the center of the larger lid. When you cut it out with tin snips or a SHARP chisel leave about 1/8" overlap on the inside. AND leave a couple tabs to you can pin, rivet, screw, etc. it all together. With the lid cut it's easy to pein the extra in to make a lip for reasonable air tightness. If you forgot the tabs solder the assembly together, other wise punch a couple holes and wire, pin, whatever the sophisticated mounting flange to the equally sophisticated custom air connection. Screw or pin it to the air valve. Everything stays in character. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
JHCC Posted February 27, 2017 Author Share Posted February 27, 2017 What is this "air tightness" of which you speak? By the way, the great oven disassembly of 2016 left me with a ton of hex head sheet metal screws, which are coming in very handy. Quote Link to comment Share on other sites More sharing options...
JHCC Posted March 15, 2017 Author Share Posted March 15, 2017 Here's the fitting to attach the shop-vac hose, made from a soup can, a section of shop-vac extension wand, and a gasket of motorcycle inner tube. And here's a video of a kindling fire going from "no blast" to "full blast" and back. Quote Link to comment Share on other sites More sharing options...
Daswulf Posted March 15, 2017 Share Posted March 15, 2017 Cool. Looks like you are ready to heat some steel in that guy. With charcoal I doubt you are going to need much of a blast with that. I'll have to make one of those one day. Quote Link to comment Share on other sites More sharing options...
JHCC Posted March 15, 2017 Author Share Posted March 15, 2017 4 minutes ago, Daswulf said: Looks like you are ready to heat some steel in that guy. Just as soon as the temperature gets up a bit closer to freezing. 4 minutes ago, Daswulf said: With charcoal I doubt you are going to need much of a blast with that. I've been burning rice coal (anthracite) mostly, but if I do go back to charcoal at any point, it will be easier to regulate the low blast. 4 minutes ago, Daswulf said: I'll have to make one of those one day. Yeah, but you can make one out of metal, with that sweet new welder of yours! Quote Link to comment Share on other sites More sharing options...
Daswulf Posted March 15, 2017 Share Posted March 15, 2017 So you are getting good results with the rice coal in the jabod? Quote Link to comment Share on other sites More sharing options...
JHCC Posted March 15, 2017 Author Share Posted March 15, 2017 Haven't done a coal fire yet, but I was using it to good effect in the rivet forge (which was clayed to have a very similarly sized firebowl). My daughter has a project she wants to make before the end of spring break, so I'm expecting to fire it up within the next few days. Quote Link to comment Share on other sites More sharing options...
JHCC Posted May 3, 2017 Author Share Posted May 3, 2017 On 3/15/2017 at 11:31 AM, Daswulf said: So you are getting good results with the rice coal in the jabod? Resurrecting the thread: Yes, hot enough to burn a piece of 5/16" x 1-1/4" into a corn chip. Quote Link to comment Share on other sites More sharing options...
Daswulf Posted May 3, 2017 Share Posted May 3, 2017 better then not hot enough! You can always turn the air blast down so it's good to be able to crank it up for large stock. Quote Link to comment Share on other sites More sharing options...
JHCC Posted May 3, 2017 Author Share Posted May 3, 2017 2 minutes ago, Daswulf said: You can always turn the air blast down so it's good to be able to crank it up for large stock. I'm actually not using the gate valve at all (just leaving it wide open) since I just picked up an old variac that I can use to vary the speed of the blower. I posted about it earlier today on the new Jabod thread. Quote Link to comment Share on other sites More sharing options...
Daswulf Posted May 3, 2017 Share Posted May 3, 2017 That's what I meant. I saw that. That is a cool old " potentiometer "? Not sure exactly how it works but I know basically what they do. Love the look of that old thing same basically as the router speed controller I use isn't it? Quote Link to comment Share on other sites More sharing options...
JHCC Posted May 3, 2017 Author Share Posted May 3, 2017 The technical term is "variable transformer", and I (not being an electrical guy) have no clue how it works. I've just been told (A) that it works best with "universal motors"/"motors with brushes" and (B) that vacuum cleaners have universal motors. It certainly functions just like your speed controller. One nice thing about it is that it's basically spliced into the middle of a heavy duty extension cord, so all I have to do is plug it into the wall, plug the blower into it, and we're good to go. I'm thinking of getting a Grizzly 2x72 grinder, and I'm wondering if I might be able to use it as a speed control on that.... 6 minutes ago, JHCC said: I'm thinking of getting a Grizzly 2x72 grinder, and I'm wondering if I might be able to use it as a speed control on that.... Addendum: did some research, and the answer is NOPE. Oh, well. Quote Link to comment Share on other sites More sharing options...
gote Posted May 12, 2017 Share Posted May 12, 2017 Ingenious JHCC. Like the valve of an old steam engine. It looks as it can be much better in controlling air than the usual valves. It also means that a blower that relies on its own air for cooling the motor does not get overheated. I will keep the principle in my mind should I need to rebuild my forge. Thank you for posting. Quote Link to comment Share on other sites More sharing options...
Dueldor Posted December 3, 2023 Share Posted December 3, 2023 Hey guys, I realize this thread is only about sic and a half years old, so I apologize for resurrecting the dead lol. However I just stumbled upon this and wanted to share my air gate design as well. it actually diverts some of the air instead of just a blockage also has a choke. this is obviously before i closed it all up lol. it works awesome too! Quote Link to comment Share on other sites More sharing options...
JHCC Posted December 3, 2023 Author Share Posted December 3, 2023 5 hours ago, Dueldor said: my air gate design Looks cool. Can you describe how it works? Quote Link to comment Share on other sites More sharing options...
George N. M. Posted December 3, 2023 Share Posted December 3, 2023 i'm not sure I understand how this wotks. Could you please describe the air flow and what is the moving paert(s). I think the moving "gate" is the light colered vertical piece of wood in the top of the box. Also, what is the advantage of this over a simple buttefly valve other than getting to build a cool wooden gadget? Thanks. GNM Quote Link to comment Share on other sites More sharing options...
Frosty Posted December 3, 2023 Share Posted December 3, 2023 Lets see how close I got this. The gate is the assembly on the right with angled board, attached to the slide. The slide closes the hole in the box body when it's in the down position, opening the large square (maybe) vertical air passage. The light colored board makes the valve seat, closing the vertical passage when the slide assembly is raised. That's what I think I'm looking at but it doesn't tell me which way the air travels. It's an intriguing valve I'd LOVE to hear how it actually works from the maker. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
JHCC Posted December 3, 2023 Author Share Posted December 3, 2023 I’m guessing that the air comes in the lower left corner and exits from either the lower right corner (to the forge) or the upper right corner (waste air). It looks like the main control is the slide on the right, which is shown closed in the upper photo (slide down) and open in the upper photo (slide up). The choke slide (center vertical) is shown open in both photos, but can presumably be slid down to reduce the total air moving through the valve. In other words, it seems to me that this is a combination of two valves: one of the completely-block-the-airflow type and one of the bleed-off-the-unwanted-air type. It’s an interesting idea, but I’m not sure what benefit such a combination might have. Quote Link to comment Share on other sites More sharing options...
Jo_Bai Posted December 5, 2023 Share Posted December 5, 2023 Here is a video and explanation for it: The idea is for a blower which needs constant airflow to cool itself and can't deal with back pressure Quote Link to comment Share on other sites More sharing options...
JHCC Posted December 5, 2023 Author Share Posted December 5, 2023 Interesting. I frankly don't see the point of the second slide. So long as the main slide goes from all-air-to-the-forge to all-air-to-the-exhaust, there's really not much more you need. Quote Link to comment Share on other sites More sharing options...
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