[TANKS] Re: Drive Cog Patterns
That post was from the old mailist where we had a files section. I've PM's the sprocket pdf to you. ST On Sunday, February 15, 2015 at 11:33:01 AM UTC-5, srwh...@gmail.com wrote: Hi Steve I must be blind but where do i find the file to download you design? Thanks Stewart On Thursday, December 11, 2008 at 6:05:15 PM UTC-5, TyngTech wrote: I've uploaded the design of my Cromwell's drive sprocket. Check out TTS Sprocket.pdf in the files section. Steve Tyng On Dec 9, 11:14 pm, Chrysanthos Kanellopoulos xchr...@otenet.gr wrote: Glad to hear. It was ony a few minute break at work here. Chrys - Original Message - From: Joker joker0...@earthlink.net To: R/C Tank Combat rctank...@googlegroups.com Sent: Tuesday, December 09, 2008 11:17 PM Subject: [TANKS] Re: Drive Cog Patterns Thanks. This was great. I took the photo, scalled it, inverted the colors, and i'm using it as the template. Thanks again. On Dec 8, 4:41 am, Chrysanthos Kanellopoulos xchr...@otenet.gr wrote: The diameter of the inner circle (green) could be 0.0873, with the clear distance between the teeth 0.0350 = 1 3/8. That way, the pads fit between the teeth. The width of the tooth ~ 0.064 or 0.0638 m. or 1/4 wide. The diameter of the outer circle, on the edge of the teeth would then be 0.0993 m. = 3,901 I hope that helps and it is not more confusing! Chrys JOkers sprocket7.3.jpg 123KViewDownload JOkers sprocket7.4.jpg 66KViewDownload __ NOD32 3434 (20080911) Information __ This message was checked by NOD32 antivirus system. http://www.eset.com -- -- You are currently subscribed to the R/C Tank Combat group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat+unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups R/C Tank Combat group. To unsubscribe from this group and stop receiving emails from it, send an email to rctankcombat+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [TANKS] New Track Idea
Frank, Thank you for the details about the horn design. That is exactly what I was looking for. I really do appreciate your help despite it seeming like it is falling on deaf ears I truly am taking your wisdom into account. Also, thank you for the suggestion about the plastic to use. Now that I think what you said it makes sense. I finally got some new resin and parts for my Form1 3d printer. All the parts I have show were printed on my Makerbot which is cheaper and faster to use, but less accurate. I currently have some parts printing on the Form1 which I will use as the master for the silicone mold. Then I can test out the over-molding process, and get parts that are in the correct durometer rubber. I also plan on using the Form1 to make masters for the horns and cast them out of polyurethane. These should be single part molds and easy to make. Fingers crossed. * - This brings up another question I had; I am going to mold them in a Shore A 70 rubber, which is basically the same as car tires. That was my best guess at what would be a good material for things. * *Why Roller Chain?* I will again restate the reasons for my design decisions. The idea of using roller chain as the foundation of my design gives me a few key aspects which I am fond of. It is a standard design with many off the shelf parts working with it. Most notably the sprockets. Using standard roller chain means that I do not have to make custom sprockets. This might seem like a small thing if you only planned on using one sprocket size. But I really like the idea of using any size sprocket. These sprockets are also already design with many different methods of attaching to shafts. McMaster has about 100 sprockets for #40 roller chains. Diameters range from 1.67 all the way to 15.57. Idlers with built in bearings, machinable bores, finished bore with keyway, nylon, metal, bushing, taper lock and more. In addition to the sprockets, you have tensions, idlers, and the design tools that help you select the perfect spacing of multiple sprockets in a chain system. I am still thinking robotics an not just tanks. If I were to design a system that has a molded connecting link this would be an additional part to design and I would have to make custom sprockets too. Like I said before I could design one sprocket, or maybe 10. But then I have the cost of making them, storing all the sizes, tooling costs, and I am never going to have 100 types for each size chain. In addition to the sprocket and accessory aspect, roller chain is very durable and has known tensile ratings. This is similar to the metal bands that are placed in the solid rubber tracks found on construction vehicles. The rubber tracks I am getting injection molded are not taking the loads. The chain will take it. I like that aspect as well. One final thought about the roller chain links is the cost. Roller chain is $13.92 for 10 foot of #40 chain. #40 chain has a pitch of 0.5, so that means 240 links. That is 5.8 cents per link. I don't think I could get links made that cheap even in quantities of 60,000. Maybe I am wrong. Or maybe I am missing something obvious to you guys that know more about this. But those are the design aspects which made me like this idea of using roller chain. You mention the width of the track not being flexible in this design. I agree with that. I have not found a good way of doing that. It is much cheaper to injection mold over a dowel pin then to make a hole. Talking with the injection molding companies I work with, having a hole will make the mold tooling and per part cost go up substantially. I even asked about molding over a metal tube. But that is problematic as well. I think for now I will have to settle for picking a single width for each size chain I want to work with. For now that is #35 chain being 3 width, and #40 chain being 4 width. - Do you think you could use an idler sprocket that meshed with the drive chain as bogie wheels? You might not need horns with that design. I have never seen that on tanks. maybe I am missing something obvious? As always thanks for the comments guys. I have got a lot of great suggestions, information and mostly just some place to talk about tank track. My couple friends are not really very interested in talking about bogie wheels, tread design. They just nod and say yeah that sounds cool. -- -- You are currently subscribed to the R/C Tank Combat group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat+unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups R/C Tank Combat group. To unsubscribe from this group and stop receiving emails from it, send an email to rctankcombat+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [TANKS] Re: Drive Cog Patterns
Im just glad to see my friend Chrys Kane back on rctankcombat after a long spell away. Neil R On Tuesday, December 9, 2008 at 8:14:51 PM UTC-8, Chrys Kane wrote: Glad to hear. It was ony a few minute break at work here. Chrys -- -- You are currently subscribed to the R/C Tank Combat group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat+unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups R/C Tank Combat group. To unsubscribe from this group and stop receiving emails from it, send an email to rctankcombat+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [TANKS] New Track Idea
This is just my personal opinion but Id choose a much steeper side angle than what you have printed. I dont think there will be an advantage having any more that 5 degree off the horizontal . Why do you want to use 3 guide teeth ? https://lh6.googleusercontent.com/-H4eFWZdYTek/VOFLbS4_uKI/BaU/9mwJdKPKiNU/s1600/20150215_202022.jpeg https://lh3.googleusercontent.com/-McJcZdHpHSQ/VOFLYPmBVEI/BaM/D9W43Vw2fYs/s1600/20150215_202139.jpeg -- -- You are currently subscribed to the R/C Tank Combat group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat+unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups R/C Tank Combat group. To unsubscribe from this group and stop receiving emails from it, send an email to rctankcombat+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [TANKS] New Track Idea
Thanks for your comment about the 5° angle. The ones I have now are 22.5°, but those were just me picking a starting point. If you read my previous post I mention that I am not planning on using 3 guide teeth / horns. I am just showing both center horns and side horns at the same time. You would pick one or the other when assembling the track. I am planning on getting the tracks injection molded, so I want the design to be modular. It is easier to change the design now before the mold is machined. Josh On Monday, February 16, 2015 at 9:01:42 AM UTC-5, neroc1 wrote: This is just my personal opinion but Id choose a much steeper side angle than what you have printed. I dont think there will be an advantage having any more that 5 degree off the horizontal . Why do you want to use 3 guide teeth ? https://lh6.googleusercontent.com/-H4eFWZdYTek/VOFLbS4_uKI/BaU/9mwJdKPKiNU/s1600/20150215_202022.jpeg https://lh3.googleusercontent.com/-McJcZdHpHSQ/VOFLYPmBVEI/BaM/D9W43Vw2fYs/s1600/20150215_202139.jpeg -- -- You are currently subscribed to the R/C Tank Combat group. To post a message, send email to rctankcombat@googlegroups.com To unsubscribe, send email to rctankcombat+unsubscr...@googlegroups.com Visit the group at http://groups.google.com/group/rctankcombat --- You received this message because you are subscribed to the Google Groups R/C Tank Combat group. To unsubscribe from this group and stop receiving emails from it, send an email to rctankcombat+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
