Hi, the openscad files are all on thingiverse. Not terribly well documented, I'm afraid, but there are parameters that you could use to change it to 6 rollers. I have only tested it with 3 and 4 rollers. You would also have to make the diameter of the pump larger.
Reef-pi build with DIY dosing pumps
- Thread starter babrooks
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Which params should I change for 1mm ID / 4mm OD hoses and 2mm ID / 4mm OD hoses?
this pumps need a lot of print hours, i prefere to make the changes properly before wasting half a day in print.
I think I have to set the following for a 1mm ID / 4mm OD tubing
Code:
tubewallthickness=1.5;
tubeOD=4;because: (OD - ID) / 2 to calculate the single wall thickness. (4 - 1)/2 = 1.5
I've also seen that your version needs the wall braket to work (because the stepper motor is mounted there).
Could you please make a version to directly mount above the stepper motor, like the original Ralf desing ?
Could you please make a version to directly mount above the stepper motor, like the original Ralf desing ?
@babrooks please help me to understand. If I understood properly, a peristaltic pump is a simple rotor with bearings (let's assume a 80mm outer diameter, including bearings) than rotates inside a stator with a bigger diameter. The difference in these 2 diameters, is the tube wall thickness.
In example:
1mm ID - 4mm OD - wall tickenss 1.5mm (3mm total thickness when squeezed).
rotor 80mm
the stator should be 80+3mm = 83mm
Is this true ?
maybe even @Borat could help me to understand the math
In example:
1mm ID - 4mm OD - wall tickenss 1.5mm (3mm total thickness when squeezed).
rotor 80mm
the stator should be 80+3mm = 83mm
Is this true ?
maybe even @Borat could help me to understand the math
Borat
Valuable Member
Thats correct, except 3mm here it the difference between 2 radius, not diameter.
The "roller" module takes an argument which is the number of rollers, so you can just generate a new scad file where you call roller(6), and that should give you 6 rollers.
Your numbers for tubediam and tubewallthickness sound reasonable, but you may need to get it dialed in.
You would also want to make overalldiam larger, and you could make it 83mm. That seems pretty big to me, just looking at the roller it seems like it would work with a much smaller diameter, say 60mm. Other parameters would need to be adjusted as well. I just experimented with overalldiam=83mm, and looking at the base in openscad, it seems that postwidth would have to be decreased, say to housingwidth/9. Also, you would need to set the brass inserts much deeper into the roller so that the set screws could reach the shaft. I don't think there is a parameter that controls this; the roller module would have to be modified.
I can make a new version of the base that attaches directly to the motor. It will take me a day or two. You would have to make cavity in the pump base for the base of the rotor of the NEMA17, and also add countersunk holes to attach the motor, as in the bracket I designed. This shouldn't be too hard to do, largely just a copy and paste of code from the bracket module into the base module.
my numbers was Just a sample for the thread. real numbers are 1mm ID and 4mm OD
Now that the math for the pump is clear to me, as confirmed by Borat, i can design a new pump on my own with scad, but, if you want to add some options to your core to make a "standalone" version of the pump, like the Ralf's one, let me know and i'll wait.
Now that the math for the pump is clear to me, as confirmed by Borat, i can design a new pump on my own with scad, but, if you want to add some options to your core to make a "standalone" version of the pump, like the Ralf's one, let me know and i'll wait.
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