jcrous Posted September 13, 2009 Share Posted September 13, 2009 Hello, I would like to know the following information about a hand crank blower: The gear ratio: number of teeth of the four gears and the diameter of the fan-example: first gear (mounted on shaft of handle) 120 teeth second gear 30 teeth 3rd gear (angled teeth) 120 teeth 4th gear (angled teeth and mounted of fan shaft) 30 teeth or 1 complete turn of the handle will turn the fan blade 16 times plus the diameter of the fan. I do not mind for several replies in different formats. The second option may be the easiest option. I am trying to figure out the second option and the size of the fan. I am tired of searching and waiting to try to get hold of a hand crank blower. so I will try to make my own. I think I will be able to get hold of the gears, but I may have to use a gear train of six gears. If I succeed I will make a blue print available. I have seen what others have done and I am confident I will be able to do it as well. Even if I have to turn the bushes or bearing housings myself, I will do it. Let's call it my personal "anti passing of the years and the unavailability of old stuff" campaign. Any photographs of the fan's prop will also help. However I may make the fan part of more modern design. Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 16, 2009 Author Share Posted September 16, 2009 I was serious when I posted the question. Information of who can answer my question will also help. Quote Link to comment Share on other sites More sharing options...
Grafvitnir Posted September 16, 2009 Share Posted September 16, 2009 (edited) I've been looking for the same info but haven't found anything concrete yet. I know J.B. Stokes made them with bicycles in Africa, but he never published that (at least that is what I've been told) I've seen pictures of them in Africa, Vietnam, Middle East, Oceania... almost always with a belt instead of gears. This linkl is for a document on Indonesian Technology. On page 127 (pg. 129 of the .pdf) you Edited September 16, 2009 by Grafvitnir Quote Link to comment Share on other sites More sharing options...
irnsrgn Posted September 16, 2009 Share Posted September 16, 2009 make a 12 inch diameter fan housing 2 inches wide inside. make an impellor with 6 arms and put tin flat blades on it, on the shaft coming out one side, put a 1 inch diameter driven pulley, Use a bicycle tire and rim inflated to run against the driven pulley, just the opposite of a tire hammer drive, add a handle and make lots of smoke and fire in your fire pot. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 17, 2009 Share Posted September 17, 2009 (edited) I'll try to get out to the shop this weekend and test, Since my wife is bedridden right now it's hard to get out there during the week. Note that it's not only the ratio but how well it runs! If the handle won't make 3 or more turns on it's own after you let it go then I don't go for it---having to crank *constantly* is a pain! Small electric blowers are a common fix for the unavailability of old blowers... Edited September 17, 2009 by ThomasPowers Quote Link to comment Share on other sites More sharing options...
Frosty Posted September 17, 2009 Share Posted September 17, 2009 Ruben: Are you the one who first posted the VietNamese blowers here? I see you have one shot I hadn't saved earlier. The Togo smithy looks to be a pretty prosperous business with a modern double horn anvil and a large masonry forge. You make a good point Thomas. If you fill the bicycle tire with water or Prop Glycol antifreeze for cold country the added inertia will keep the blower turning for much longer. Frosty Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 17, 2009 Author Share Posted September 17, 2009 Thanks Rub Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted September 17, 2009 Share Posted September 17, 2009 Have you looked at converting a hand crank grinder to run a small blower? Gear work already done! Quote Link to comment Share on other sites More sharing options...
Grafvitnir Posted September 17, 2009 Share Posted September 17, 2009 No Frosty, I found the third photo somewhere else, Flikr, of someplace like it. I was looking for images of blacksmith setups in google images and typed something like "Viet Nam blacksmith blower" or something like that. The other two Viet Nam blower pictures came from here (iforgeiron). Rub Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 18, 2009 Author Share Posted September 18, 2009 ThomasPowers, I have thought about that some years ago, but I think it will be too slow still. The gear ratio may be Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 18, 2009 Author Share Posted September 18, 2009 I immediately searched for Viet Nam blacksmith blower, and I came across this link:http://www.iforgeiron.com/forum/f92/blower-rebuild-advice-needed-14397/index2.html. I can maybe start on the formulas of this setup, but I am sure I can design a blower that will have a more effective fan and then maybe I will only need a gear / wheel setup that will be slower. I worked in my thoughts with the following: Ypu can crank a blower at about 100 turns per minute. The 2 sets of gears are 1:5, therefore the first set will turn at 500 turns per minute and the second one then at 2500 turns per minute. This is maximum. You may need to turn much slower, or the flames may be too hot. Maybe I am totally wrong in my assumption. Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 19, 2009 Author Share Posted September 19, 2009 I have visited the auction shop but the grinders are not what I want the bigger gear runs directly against the second axle, into which were milled slots to resemble a gear. Low quality. I will rather wait. I am going on holiday in three days time and then I will hunt all the antique and second hand shops in several town. Maybe I will get lucky. If not I will buy a set of gears and rather take the long way. I will also look at a more effective way of making the fan blades. Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted September 19, 2009 Share Posted September 19, 2009 Is this for a stationary setup or a portable one? If it is stationary, bulk may not be that big of a problem. Too bad the shipping is so high, as I see hand crank blowers here in the States fairly often. I would look into a bicycle chain drive with a flywheel, easy, cheap (free), lightweight, easy to crank, and easily repaired if needed. The bigger the fan is the less RPM's needed for the same volume of air. You need volume, not pressure. A large fan at low RPM may work best as the fan can double as a second flywheel , if it has some weight to it. Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 19, 2009 Author Share Posted September 19, 2009 I would like portability. My first choice would be the real one but if it can not I would not mind to make my own. I personally would prefer to use proper cast iron pulleys above bicycle rims. I have seen them in the past and I just need time to look for them. I will look at a fan diameter of at least 12 inches and about 3 deep. I am planning to use about 8 fan blades with a rather tight fit. As I have mentioned I would like to melt brass too in my forge. I have access to good resources as I own a lathe and both gas and arc welder. I also have access to mig and TIC and spot welder at my cousin, so I will be able to do it. When finished, I will publish the blueprint. Quote Link to comment Share on other sites More sharing options...
arftist Posted September 19, 2009 Share Posted September 19, 2009 I have a Buffalo Forge Company Blower. The fan is 11"(27.5cm) diameter. The reduction is one revolution of hand crank gives 50 turns of fan blade. The thickness of fan is 1"(2.5cm) The outlet is 3"(7.5cm) It is a BIG blower. 12" diameter x3" thickness x 25-1 ratio would take a very strong arm to turn. You can buy mine if you want. It is brand new, never used. PM me if you like. Quote Link to comment Share on other sites More sharing options...
jcrous Posted September 20, 2009 Author Share Posted September 20, 2009 (edited) The reduction is one revolution of hand crank gives 50 turns of fan blade. 12" diameter x3" thickness x 25-1 ratio would take a very strong arm to turn. OK, if I get it right yours is the 50:1 for a 11"X1" fan. Now I think I understand why the blowers have such a long handle. Then I think I must calculate for a 30 rpm turn of the handle. With a 50:1 you will get the fan to turn at 1500 rpm. If I work with 7:1 X2 and I turn the crank at 30 rpm I will get 1470 rpm for the fan. If I get the fan to the 11" X 1" dimensions, I think the torque will be more or less the same, but I can try to improve on the blade design. Thank you for your information, that was what I was looking for in the first place. Now I know what to look for. Unfortunately I live in South Africa, so the shipping and import tax will kill me. Edited September 20, 2009 by jcrous wrong fan figures Quote Link to comment Share on other sites More sharing options...
Dave Parker Posted September 22, 2009 Share Posted September 22, 2009 Johan, This will help:http://www.cd3wd.com/cd3wd_40/JF/JF_VE/SMALL/04-110.pdf I am going to use this to rebuild my blower. Dave Quote Link to comment Share on other sites More sharing options...
jcrous Posted October 4, 2009 Author Share Posted October 4, 2009 Thanks. I am now back from my holiday and I expect my new laptop tomorrow, sow I will be busy migrating to portable, but I have taken some pics of a museum that have reconstructed an open air scene. I will post when I can. Quote Link to comment Share on other sites More sharing options...
OddDuck Posted October 4, 2009 Share Posted October 4, 2009 Dunno if this helps, this is the second blower housing I cast, I was actually thinking about putting a kit in the tailgating section if there was sufficient interest. The first housing I cast using this method is the one that runs my forge. It pushes plenty of air, it's ten inches in diameter and the internal width is about 2". I'm mentally working on the design of a casting for using this as a hand cranked instead of a motorized blower. I can even cast your forge name into the side. Shipping would be pretty reasonable, it should fit into a large flat-rate box. The casting for the impeller base would be included as well. Trades would definately be considered. Sounds like the problem you are having is the gearing setup, though. Have you thought about using bicycle or motorcycle chain? Might be a tad noisier, but you can get the chain and sprockets easily nearly anywhere, and would definately be a very positive drive. Might make the search for bearings and shafting easier as well. Quote Link to comment Share on other sites More sharing options...
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