below are answers On 19 August 2017 at 12:52, Luke Kenneth Casson Leighton <[email protected]> wrote:
> --- > crowd-funded eco-conscious hardware: https://www.crowdsupply.com/eoma68 > > > On Sat, Aug 19, 2017 at 11:38 AM, Hrvoje Lasic <[email protected]> wrote: > > Ok, so correct me if I am wrong but you are asking some mechanical > > questions. > > mechanical / physics, yes. > > > so, I speak in general now and if you have question ask deeper. > > > > Force needed to drive whatever you want to drive will be exactly the same > > at the end part of system. > > on the print-head yes. but because of the doubled speed, the DRIVE > end *NO*, the force is NOT the same. > so, if on the print head-side force is the same then it is on the drive side same as well (work can not be missing somewhere). However, if you are doubling the speeds, then overall work required will be some higher value so, correct would be to say that because of double speed you are having more force on print head needed and as result drive will also have to work more, losses will be bigger etc. anyway, that is all theoretical. Real value would be to find out force you need to have on print head then do some sort of calculation back to the drive. I guess you don't know that but maybe you can see what has been done on system that have other drive and then try to extrapolate what you will need. We can also assume here that someone has already put some reserve on what is now there, so possibly you can leave same motor or if you have problem increase force at disposal assuming you can do that on same motor size (nema 17 or so) I think backlash here will be your biggest problem here. Backlash is in fact inertia of the system. So, for example when you run you want to stop you cant do it right away, you need some time/distance. Or comparing to electrical engineering you can compare it to inductance. Inductance is resistance plus reactance. You said that you expect lesser backlash on pulley system. If that is the case (I am not sure why or why not this statement would be truth) you will be able to increase speed up to certain point but you will have to test where is that point. Basically you will have to do a lot of testing. > > > But efficiency of belt system could be slightly > > different then efficiency of `non` pulley system (whatever it is). But > > again, efficiency could be neglected for sake of easy of calculation or > you > > can put around some value that (guess) could be 80-90%. > > i'm assuming that there are no significant losses around pulley bearings. > > > What you will be looking is gear ratio on pulley that could alter > > force/speed ratio and same thing on other system. > > the gear ratio on a single pulley system is 2:1. > > > also, you will be looking on backlash. > > *thinks*... backlash should be reduced (halved) due to the better > effectiveness of the pulleys - assuming that there is no "play" in the > bearings (we can assume decent bearings / idlers). > > l. > > _______________________________________________ > arm-netbook mailing list [email protected] > http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook > Send large attachments to [email protected] > -- Hrvoje Lasić Vulpes d.o.o. Gračanska 120a 10000 Zagreb Croatia tel +385 1 6152 706 <+385%201%206152%20706> tel +38598 450 603 <+385%2098%20450%20603> *[email protected] <[email protected]>[email protected] <[email protected]>m* *www.vebbu.co <http://www.vebbu.co>m* _______________________________________________ arm-netbook mailing list [email protected] http://lists.phcomp.co.uk/mailman/listinfo/arm-netbook Send large attachments to [email protected]
