hy guys, i dont think i made myself very clear. forget the 5.5-6.5 gears with different teeth counts. what i was trying to say, would a larger dia pinion say 8mm 13t and a larger gear 39t be any different to a 5mm pinnion 6t smaller gear 18t be any different, in performance of the motor. bearing in mind their both 3-1 ratio with vastly different mechanical leverages. i do know the effect of changing ratios. but i,d like to know the effect of different size pinions and gears with the same ratio. forget the cars ect, this is a hipothectical question, to do with leverage and torque changes. i think its a very basic question with i suspect a complicated answer, which i cant work out myself. so keep the explananation simple for me. thank john
same ratio dfferent gears
hy would some one like to explain the different combo,s, and why. take a 3-1 ratio, the standard is 9-27. going to extremes, what about 7-21 or 11-33 there must be a difference and i,d like to know. a euro sport runs 6-1 6-36 why. john
1 - 13 of 65 Posts
does a big dia pinion give the motor an easier time than a small dia pinion.john
the best ratio for a neo drag car is 14-54- 64 pitch. you can use a smaller pinion and gear to get the same ratio,s the drag boys do hundreds of gear changes to get the right combo, so why go with the bigger heavier gears, when weight is a big issue in drag cars, same as 1/32 and 1/24. what i.m getting at does a large pinion with more leverage slow a motor down, or is it such a small amount in the leverage ,not make any difference. ive seen old 16-24 pinions, why make them if theres no advantage. john
that wasn,t the question rick take a 14t pinion 9mm in dia and mate it to a 42 gear 3-1 then take a 6t pinion 5mm in dia and mate it to an 18t gear. whats the advantage, does a big pinion drop motor torque or does a small pinion increase motor torque.pretend that wheel, ground clearance isnt an issue. why would you go for the different pinions and gears to achieve the same ratio 3-1. there must be a very good reason judging by the racers and scratch builders setups. i hope this is a bit clearer. john
no wind up rick, not my style. that has answered my question, you go for the biggest gear set that will fit into the car and you achieve better gear mesh and less frictional loss. bigger pinion and gear makes no difference to the motor, i think i,ve got my head round that. thanks dude john
wish i hadn,nt started this thread. i was just wondering, as you do in idle moments. i got the answers and i,ll play with the ratios on a 1/24 anglewinder, with slots for positioning the motor where i want it. should be dead easy to play with the pinion and gear sizes. like john i,ve got some old solid brass gears all different sizes and weights, that should provide a laugh. cheers john
i actually got the 48p brass gears in a job lot of very interesting old parts, it would make you cry, cos i got them dead cheap i almost felt sorry for the vendor. like you i prefer the delrin type gears, but in 64p for most applications. i find it gives me more scope in the size dept, cheap parma gears arn,t bad but i like the kofords better and falcon does a nice thin lightweight metal spur. i only use brass and steel pinions even on scaly motors i just rub a fine file over the splines whilst the motor is turning. john
thats a smashing looking car rick, i especially like the detailing youve put into the lexan body. just shows what can be done to a lexan with patience and a lot of skill. i like! john
slightly of original topic, but i just found a crown gear for 1/24 gp or narrow wheelebase cars. its a 36t-48p gear, but the interesting thing about it, is its made to run a full 3/16 offset, to get the motor low in this type of set up. i made a u bracket with the 3/16 offset, i used an old parma 10 tooth pinion and couldn,t believe it. they are the quietest gears ive ever heard? and the mesh is perfect, set up with a *** paper as usual for me. just right for my merit 1/24 talbot lago gp car. john
hy rico, just rereading the thread. all gears work on a sliding action thats how the pinion moves them. as the pinion revolves, the tooth thats been pushing on the big gear slides of, the next tooth thats engaged should just be starting to push. with a pinion of 5.5mm dia and different tooth counts,, look at the profile of the teeth. you go from a v shape on the 8t to a waisted profile with a little flatted ball on top in the 10t pinion, for clearance. this allows many different teeth sizes in a given diameter. im talking about inline motors, but the same applies, to a [fixed pinion and gear centres] on an anglewinder and sidewinder. down to the reason i was leading upto. gears are cut on a hob with the cutter set at a right angle to the centre of the gear so if you want a 1/8 offset you just move the cutter down 1/8 and cut the gears. this will give a perfect gearmesh if set up correctly at the 1/8 offset. it wont work if you try to set it it up in a straight line. the 1mm offset on slot it gears are a bit of a fudge up, it just happens that a slot it gear[inline] thats been cut on the centreline will work nearly as well if its been set up with a 1mm offset, if you tried to offset it anymore than 1mm you,d run into trouble pretty fast. end of my one finger typing marathon. john
hy rico, just rereading the thread. all gears work on a sliding action thats how the pinion moves them. as the pinion revolves, the tooth thats been pushing on the big gear slides of, the next tooth thats engaged should just be starting to push. with a pinion of 5.5mm dia and different tooth counts,, look at the profile of the teeth. you go from a v shape on the 8t to a waisted profile with a little flatted ball on top in the 10t pinion, for clearance. this allows many different teeth sizes in a given diameter. im talking about inline motors, but the same applies, to a [fixed pinion and gear centres] on an anglewinder and sidewinder. down to the reason i was leading upto. gears are cut on a hob with the cutter set at a right angle to the centre of the gear so if you want a 1/8 offset you just move the cutter down 1/8 and cut the gears. this will give a perfect gearmesh if set up correctly at the 1/8 offset. it wont work if you try to set it it up in a straight line. the 1mm offset on slot it gears are a bit of a fudge up, it just happens that a slot it gear[inline] thats been cut on the centreline will work nearly as well if its been set up with a 1mm offset, if you tried to offset it anymore than 1mm you,d run into trouble pretty fast. end of my one finger typing marathon. john
27-9 is a 3-1 ratio, which is neither here or there. you,ve got the concept upside down. the very tip of the pinion does all the work and the mechanical advantage does change as you said. take it that that the pinion is fully engaged on the centre line, as the pinion revolves, the tip only, slides along the land of the driven gear pushing it downward till it disengages and the next spline of the pinion slots in. at no time should the back of the pinion spline touch the rear land of the driven gear. hence all the funny tooth shapes, which are found on different teeth counts with the same dia pinion. idealy the top of a pinion tooth would be ball shaped, to minimize friction and noise as it rolls-slides down the land of the gear thats being driven. john
1 - 13 of 65 Posts
- This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
SlotForum
A forum community dedicated to slot car owners and enthusiasts. Come join the discussion about collections, racing, displays, models, track layouts, styles, reviews, accessories, classifieds, and more!
Full Forum Listing
Explore Our Forums
Recommended Communities
