Any Idea to create home made gears?

[Guest]

Anyone, I have one gear that is about 7 inches wide in circular diameter, and I wanted to have another one for throttle quaduant. And I went through so many websites, making few phone call to any manufacturers that build different types of gears. Nevertheless, none of them have one that is 7 inch es wide in diameter. So however I decide I could just build one of those myself. I was thinking maybe I could just try to find any type of plastic that is similar or almost similar to the gear I am having and have it cut off in round shape by using circular saw and then, cut in teeth by using jigsaw. But I thought, it would not be possible because that gear would not be able to hold in shaft without allenwrench type screws. I thought maybe using other methods by creating mold clay and let it dry overnight, then it'd have a fossil like shape of gear. And then I'd melt any type of plastic from the boiling water pot and pour it in the molding clay...Actually I dont know how, but I have heard it from somewhere through this fourm/ Any Ideas??? sharing ideas or your experiences would be appreicated.

[Guest seev_39]

Hi BizzyBee,> I thought maybe using other methods by creating mold >clay and let it dry overnight, then it'd have a fossil like >shape of gear. And then I'd melt any type of plastic from >the boiling water pot and pour it in the molding >clay...Actually I dont know how, but I have heard it from >somewhere through this fourm/ Any Ideas??? sharing ideas or >your experiences would be appreicated. Casting Polyester (kind of plastic) gears with a mold was discussed on this forum under "Reverse thrust mechanism" sometime in the middle of Jan. I tried this method and it works. Just look there for the details.The attached pic shows the clay model (with cucumber can steel strip to make the "teeth"). The pic was in the forum but since then deleted.Have funSeev

[Guest]

Arthur,Another idea. Contact Pete Cos. If you provide the dimensions, I'm sure he can laser cut them for you out of thick plexi.Michael

[Guest]

Hi Seev, where do I happen to find casting polyester and steel cucumber can?If you are in America, would Wal-mart be the best choice?Mike, That would be my last option about asking Peter Cos to do some laser cutting if I couldn't successfully build my own gears. Thanks for the tips.

[Guest seev_39]

>Hi Arthus, >> where do I happen to find casting polyester and steel >cucumber can?If you are in America, would Wal-mart be the >best choice? The materials needed for casting; you can use any liquid polymer that is prepared by mixing two materials (called normally material A and Material :(. When you buy it ask for a material that will become hard after curring. First make your model wheel out of clay, then cast over it artificial rubber (again, it is prepared by mixing two meterials). Then take out the model and cast into the cavity (a "negative" of your wheel) the polymer.All materials are available in hobby shops, or hardware shops. Once you do it you will find it is a very creative way of producung your own designs. No, I don't live in America, but I assume you can find those things easily.As for the steel strips, maybe I did not make myself clear enough. I took a used can and cut out the strips from it with steel scissors. For my gears I used 8 mm wide strips and bent them with a pair of pliers. Since it is a ring you have to sold it after bending.Seev

[tigert 0]

One clever idea I saw for large sized gears was by the guy who does the Fokker cockpit (dont remember the name right now, I wonder if he was on the flightsimnetwork forum instead of this..)He used wooden discs and cut pieces of those toothed belt-drive things you have on car generator and cooler fan etc transmissions. My volcabulary lags a bit behind here but I hope you get the idea.The belt looks like this:

/_/_/_/_/_/_/_/_/_/_------------------------------

So cut one complete "belt" into suitable pieces and glue them *around the discs* to get nice rubber-teethed gears, the guy used those for throttle levers etc, probably works very well for that purpose.Tuomas

[Guest seev_39]

Hi Tuomas and all,>So cut one complete "belt" into suitable pieces and glue >them *around the discs* to get nice rubber-teethed gears, >the guy used those for throttle levers etc, probably works >very well for that purpose. Good idea. At some point of my design I did the same for a trim wheel, but used a toy that I saw my grand child play with. It has a toothed plastic strip and a small gear inside a case which you can open and rework. I cut the plastic strip to envelope a plywood wheel and nailed it tight (problem is the connection).Here is a picture of the "thing".The alternator belt might work better since it gives good contact, though as you say it is for bigger, heavy duty, gears.Seev