Yes, that’s it. You would use the lathe to bore a hole through the long axis of the aluminum rod (end bore). That will ensure that hole is in the center of the rod and that drive shaft and extender shafts are concentric.
>> screwing tightly should hold shafts in place ? Well, there a lot of variables. It should work for small motors and modest torques. I have to believe that it would hold much better than the glue alternatives mentioned on the boards. If you can give your shafts a flat on one side that would help. Aluminum is good material to start with. It drills easily, is cheap, and easy to come by. It can also strip threads easily, so go slow with the screws (always good advice J ). You can get taps as small as about 1.5mm. Larger taps and set screws will probably be easier to work with and hold better than smaller ones, however. Take a trip to your local hardware store, see what they carry, and see what makes sense for the size of part you are creating. Don’t forget to pick up set screws that match the tap you select. - Doug From: Peter Pišljar [mailto:[email protected]] Sent: Thursday, December 03, 2009 3:37 AM To: [email protected] Subject: Re: [TANKS] some information needed .... thanks Doug. ok so what exactly would i need wood lathe for ? (as if wood lathe is the thing you mount a piece of wood in (or something else of course) and then start it, it rotates, and enables you to work on material on all sides equaly ... ? if i understod you correctly : ˇˇ hole for screw ˇˇ hole for screw |------ ---------------------------- ---------| | | | | | | ---------------| |------------------ ---------------| |------------------ | ^hole dor shaft | ^hole for extender |------------------------------------------------| this should work ? just screwing tughly should hold shafts in place ? what kind of metal is best to work with =? (so i can drill it ...) how small drill bits and taps is it possible to get ? 1mm ? 2 mm ? On Wed, Dec 2, 2009 at 11:13 PM, Doug Conn <[email protected]> wrote: You could probably make a small solid shaft coupler/extender using a wood lathe (you said you are well equipped for wood). I would start with a piece of aluminum rod about 9mm diameter. In the states, rod like that can be purchased inexpensively in a home improvement store. Cut off a small piece , maybe 2 cm long. Will something that small fit in your lathe ? If so, mount it and end bore a hole the same diameter as your motor drive shaft. Then, drill a perpendicular hole near one end for a set screw. Just drill until your perpendicular hole meets your axial hole. You’ll need to drill the appropriate drill size and tap for the set screw. Again, drill bits and taps (sometimes in a coordinated set) can be purchased inexpensively at a hardware store. Tapping will be a little tricky because the hole doesn’t go all the way through your coupler. What you really need is a ‘blind tap’, but that’s a more specialized tool. If it were me, I’d make due with a standard tap and then use a screw to finish out the final threads where the tap can’t reach. I don’t know what goes on the other end of your coupler. Will it mount to the outside of a small aluminum rod ? If not you could always repeat the process above on the other end of your coupler to create something that joins two shafts. Hope that helps. - Doug From: Peter Pišljar [mailto:[email protected]] Sent: Wednesday, December 02, 2009 3:44 PM To: [email protected] Subject: Re: [TANKS] some information needed .... steve and james, thanks a lot. the tools i have ... a lot to work with wood, but not much to work with metal. sure i have a drill, but the shaft i plan to use is to thin for drilling i think. do you think just using a sleeve and some glue would work ? thats basicly how the gear wheel is usualy attached to the small dc motors right ? On Wed, Dec 2, 2009 at 9:21 PM, whitney james <[email protected]> wrote: What tools do you have? If you can find a sleeve that fits around the shaft tight enough, you can slip it half way on, drill a hole through, and secure it with a simple bolt. Then, your shaft extension slips into the other end, and is secured the same way. If you want to make sure there is no play, goop the inside with epoxy before you put on the sleeve. _____ Date: Wed, 2 Dec 2009 21:06:56 +0100 Subject: Re: [TANKS] some information needed .... From: [email protected] To: [email protected] hello. thanks for the replies, but maybe i should define my question a little bit more. i know about my electronics, bout controler. yes i plan to use two motors. my only problem is building the drivetrain. i have idea how i want it to be (based on the tanks on this site). but i have more general problems, like atm: how to make drive shaft of my motor longer ? i would like to extend it a little, but have no idea how to efficently do this. duck tape idea doesnt count :) wleding is out of option. On Wed, Dec 2, 2009 at 8:27 PM, Thomas Lum <[email protected]> wrote: > >here's my list of topics i would like to know more about : > >-- motors ? i saw everybody here's using big motors with a lot of >power (120W and more) > but your models are 1/6, so thats a LOT bigger. how could i like >calculate what torque would i need, what > rpm, for my tank. i currently have 2 stepper motors, with 50mN/m (i >think thats like 40inchlbs, not sure tho) > but they seem a little bit to small. First tip, it's easier for us to build on 1/6th scale because almost all the hard work has been done for us. Most know what works and what doesn't. If you blaze out into a different direction, you are going to have to buy and test a lot of things yourself. Your motors depend of your tank weight. Make your build modular so you can switch something out easily if it doesn't work. >-- drive shafts, coupling, connecting wheels. > basicly i have no idea how to do that. i know what i would need to >do in theory, but how exactly do you connect > another longer shaft on that small shaft of a dc motor ? (its too >small to drill thru or anything) ? Most of the time the motor has a shaft that you connect either a pulley or sprocket to. You then use belt or chain to attach that to either a second belt or pulley, or sometimes directly to the main axle shafts. how do > i connect non-powered wheels (the middle ones) so they can turn on >the saft, Bearings and lock collars and how to connect the > powered wheels so they cant turn on the shaft ? Usually you use set screws, keyed shaft or you have to fabricate something to mate the shaft to the wheel (I think the Cromwell, Tiger or Comet has a good pic of this) all little things >like this, basicly some building manuals, tutorials, > books, anythings with pictures would come in handy. Read every tank build on the website, that is a bible of building. Also look at the tanks that are old and still going. Cromwell, Comet, Tiger, Hetzer, SU-100, Bad Kitty, and a few more I am forgetting. Anyone (almost) can build a website tank that never goes to a battle (me for instance), but those tanks I mentioned are punished and still run every battle. They are a guide to what works well. Also anything Frank says is gospel. -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat _____ Windows 7: Unclutter your desktop. Learn more. <http://www.microsoft.com/windows/windows-7/videos-tours.aspx?h=7sec&slideid=1&media=aero-shake-7second&listid=1&stop=1&ocid=PID24727::T:WLMTAGL:ON:WL:en-US:WWL_WIN_7secdemo:122009> -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat -- You are currently subscribed to the "R/C Tank Combat" group. To post a message, send email to [email protected] To unsubscribe, send email to [email protected] Visit the group at http://groups.google.com/group/rctankcombat
