Thanks for the feedbacks.
Some clarifications on why it's built like that / what i want to do with it.
The effector will become much heavier, probably around 1Kg, as i intend to print with pastes (clay, etc) + will take some horizontal load due to the feeding mechanism. I expect somewhere around 1 to 2Kg of vertical load, and 0.5 to 1kg of horizontal load.
The idea of the counterweights is to cover about 50% of the extruder weight. I'm looking for delta design studies with forces evaluation. Found one, that used a soft to make a simulation, the guy says that forces on the carriages are quite low. I'm still looking for a study a bit more theoretical, identifying for example worst case scenarios for Z forces and XY plane forces on the carriages.
To start with, movements will be slow, and i hope that the counterweights inertia will not be a problem. The speed will be limited by the steppers holding torque (mainly inertia, because a good proportion of the gravity load will be taken by the counterweights)
Regarding the design, agreed, there are a few design enhancements to do, especially on the motor beds.Made a few choices though :
* Motors and electronics position : placed on top because i want to print with clay & other messy materials. So i've put them as far as possible from the base, where all the mess will endup :-)
* Rigidity / swing. The clamps are here to only prevent vertical movement, and i'll be using V braces for horizontal and torsional movements (hence the clamps to prevent the platform sliding when the cables will be tensionned). There will be a few changes on that, i fear that the clamps will not take the load.
* The carriages are relatively flexible, for dampening, and to accommodate of assembly imprecisions. If it doesnt work i'll glue wood plates behind them. Made that choice because what i saw on the i3's X axis.
runninfarmer - question, the counterweights are floating, so i guess they might balance no ? wondering if i can hook my counterweights directly on the timing belt or if it'll make them swing too much.
Some clarifications on why it's built like that / what i want to do with it.
The effector will become much heavier, probably around 1Kg, as i intend to print with pastes (clay, etc) + will take some horizontal load due to the feeding mechanism. I expect somewhere around 1 to 2Kg of vertical load, and 0.5 to 1kg of horizontal load.
The idea of the counterweights is to cover about 50% of the extruder weight. I'm looking for delta design studies with forces evaluation. Found one, that used a soft to make a simulation, the guy says that forces on the carriages are quite low. I'm still looking for a study a bit more theoretical, identifying for example worst case scenarios for Z forces and XY plane forces on the carriages.
To start with, movements will be slow, and i hope that the counterweights inertia will not be a problem. The speed will be limited by the steppers holding torque (mainly inertia, because a good proportion of the gravity load will be taken by the counterweights)
Regarding the design, agreed, there are a few design enhancements to do, especially on the motor beds.Made a few choices though :
* Motors and electronics position : placed on top because i want to print with clay & other messy materials. So i've put them as far as possible from the base, where all the mess will endup :-)
* Rigidity / swing. The clamps are here to only prevent vertical movement, and i'll be using V braces for horizontal and torsional movements (hence the clamps to prevent the platform sliding when the cables will be tensionned). There will be a few changes on that, i fear that the clamps will not take the load.
* The carriages are relatively flexible, for dampening, and to accommodate of assembly imprecisions. If it doesnt work i'll glue wood plates behind them. Made that choice because what i saw on the i3's X axis.
runninfarmer - question, the counterweights are floating, so i guess they might balance no ? wondering if i can hook my counterweights directly on the timing belt or if it'll make them swing too much.