unipivot case: -all the gravity force is put on the tiny needle and made a heavy pressure on it. upside down pivot case: -magnetic force cancel the gravity force and is set only to put a slightly force on the needle (no more no less).by herve robert - Look what I made!
...is to fix the knife edge and the pivot on the same line (see schematic).by herve robert - Look what I made!
this tonearm is made with the same kind idea of the ball bearing describe in this topic: https://reprap.org/forum/read.php?152,839120 when you use a unipivot tonearm, all the weight of the arm is on needle use to made the pivot: for the up and down tonearm movement, it is easy to rotate the edge of a knife (as in a mechanical balance) for arm movement from left to right, use magnets toby herve robert - Look what I made!
the purpose of this topic is to experiment something different. for the angular movement, we could use a ball bearing like in a record player... like this: but you see the majority of the weight is on the ball and the circular shaft surface must be precisely fit with the well. but we can do in another way.. if we use magnets, we can do this it's a ball bearing too but the shaft is balancby herve robert - General New Machines Topics
when they runs, the arms on my delta printer turns left and right. to keep them straight, I use soft foam rollers (soft hair curler). I cut a slice of the roller and I mount like this (see pics).by herve robert - Delta Machines
new release for the arm extruder calibration, look here: https://mattshub.com/2017/04/19/extruder-calibration/ the scad files: https://www.dropbox.com/s/rb4mzyhejuzd62a/armMk2.tar.gz?dl=0 try dual extrusion with single nozzle, but doesn't really work: https://reprap.org/forum/read.php?70,849907,849907#msg-849907by herve robert - General
with the dual hobbed extruder: https://reprap.org/forum/read.php?1,840705 doesn't really work.. too much strings.. here my scad files: https://www.dropbox.com/s/ks90mbvuxvo22tr/dualExtrusionSingleNozzle.tar.gz?dl=0 some infos: http://wiki.3dator.com/index.php/Dual_Extruder_single_nozzle/enby herve robert - Plastic Extruder Working Group
hello, I made an archive with stl and scad files and pictures.. I'll try a dual extrusion with one nozzle with this new version.by herve robert - General
@o_lampe that's the point. I suppose an appropriate spiral shape for each angle (θ, φ, t)... cancel tracking error. in the case above spiratic shape: smallest diameter 10 cm / biggest diameter 12 cm, tape 30 microns and motor shaft diameter 5 mm = constant ratio 20 ( vs cylinder with 10 cm "constant" diameter = ratio between 16 - 20) @MKSA lucky you are if you have the paul graham's mby herve robert - General New Machines Topics
Quotejamesdanielv good luck! few chances, fun anyway...by herve robert - General
QuoteMechaBits re purpose the rotating base from this interesting you've 10 teethes gear and a 100 teethes gear ==> 10 ratio. with tape I hope an higher ratio ==> 16 or 20 or higher.. and maybe for the z axis, this design:by herve robert - General New Machines Topics
to start, I made this. a lot of mistakes and a lot to fix but I succeed to print the gear "A".by herve robert - General
I have try this with an elastic: work not so bad.. see video too. videoby herve robert - General New Machines Topics
QuoteMKSA -As shown however, idlers will interact and one may prevent proper push of the other against its hobbed gear. in other words, if there is to much pressure in one side there less pressure in the other side... good or bad ?by herve robert - General
QuoteMKSA Quoteherve robert triple hobbed: Just wondering why the "idlers" are set that way, on the same articulated arm ? "idler" wheels can be set on individual independant mechanisms. but for each arm you need a push spring. another purpose is: to build an automatic or semi-automatic filament loading. on the video the sequence isn't exact. first, the unloading: step (B ), the "oraby herve robert - General
Eric's Wade's Collaborative Dual Feed Extruder Double hobbed extruder Rubber drive wheel triple hobbed: videoby herve robert - General
yes that's it: "dual hobbed" / more accurate name ! a kind of it: thingiverse with two motors, seems to be a good solution but to heavy in my case.by herve robert - General
yes probaly need of lot experiment to fix all this stuff ! thank you for the code I will look closer to the work of Nick Seward I want to try this too it s more about the extruder so I made a another topic. Dual drive extruderby herve robert - General New Machines Topics
I was wondering about my pantograph printer ( topic here ) when I have think about this thing why not use a gear of this kind (I have seen many kind of extruder drive but no kind like that): It's like of some push pull drive and the both side of the filament are be drive (the pics are just sketchs) animate pic: video (better if you download the file and open it with your browser)by herve robert - General
thanks. I didn't know the wally printer concept as far as I understand, it seems that the bed elevation is not balanced ... yes, probably need some code tweaks to had the right print head movements. about the use of belt.. maybe... strings or ribbon... with weight for backward movements of θ, t . not quite totaly sure...by herve robert - General New Machines Topics
maybe CV-joint could be a very good design to cancel the angle. not very easy to drive the filament in the heater and today I made this sample of gears to drive the turntable. the motor as a counterweight is a good idea tooby herve robert - General New Machines Topics
sketch with openSCADby herve robert - General New Machines Topics
yes , it's true. it's not easy to print near to the center of rotation. if you move in the Y-direction, you have to move the turntable mecanism too or the pantograph. but look a this (it's only hypothetical): but the main idea is the pantograph. one point is to built a direct drive (instead of the bowden system) but without an overload the filament drive motor is not at the end of the cantiby herve robert - General New Machines Topics
hi everyone some features "expected". - balanced-arm with a counterweight - least amount of parts, no or no long belts, no rods, .. - majority of printed (or cnc) parts - easy to built - bargain price but good quality too - (θ,t) simple bearing like in record player turntable - small printing size (about pantograph, I'm worried about the size of he arm. if it's too long, it could be wagging (anby herve robert - General New Machines Topics
this is two videos: videoA videoB it's not exactly like R360 printer. you've got a turntable too but there are three angular movements (θ, φ, t). (r360 have two linear movements X,Z and a angular movement)by herve robert - General New Machines Topics
hello folk's I've got this idea since a couple of weeks. see pictures. it's just a model. lot to do before it works. but it seems interesting. +by herve robert - General New Machines Topics