Large Delta printer build - advice and suggestions welcome

[curious aardvark]

how can you have a 500mm bed with a 381mm (15inch) centre ?

Other than that, sounds good.
But the printer itself isn't that large - so not sure why you want nema 23 motors.

The best thing to look at - as far as measurements go - for a delta is the smoothie ware, guide and wiki. Gives you all the rod measurements and angles, etc.
Reall helpful.
I presume the skyr 1.3 runs smoothieware ?

[Reefsider416]

how can you have a 500mm bed with a 381mm (15inch) centre ?

Other than that, sounds good.
But the printer itself isn't that large - so not sure why you want nema 23 motors.

The best thing to look at - as far as measurements go - for a delta is the smoothie ware, guide and wiki. Gives you all the rod measurements and angles, etc.
Reall helpful.
I presume the skyr 1.3 runs smoothieware ?

My design is a little hard to describe; The 15" rim will be the center hub but the towers/uprights will be bolted to the outside of the rim so they will extend beyond that by about 4-5" for each tower/upright making the usable bed area about 500-600mm I think. I will then connect the backs of the pillars with 2040 extrusions or maybe bigger depending on how much room i need under the bed. Hopefully I will be able to finish the CAD drawings soon and that will tell me exactly what the area I have to work with is. Once I finish the part designs I will post them on here. I don't have the actual rim yet as I haven't been able to meet up with my friend that grabbed it for me. I also haven't figured out what steppers and linear rails to use so I haven't found the CAD files for those yet either.

I chose the nema 23 because after looking it seemed to be the common size for that size printer but i would rather do nema 17 if they will work just as well. I am on a budget, most of the parts have been donated by friends and keeping the cost down is important.
On that same point, if i can use nema 17 motors does that mean 12mm linear rails are sufficient? That could reduce costs also.

The SKR v1.3 can use a variety of different software/firmware including smoothieware. It can also run 12V or 24V so I intend to run 24V and hopefully a 120V silicone heater. They also sell 12/24V versions but if it's not too difficult 120V would heat faster. To use a 120V heater, how do i set up the temperature controls? Is there another board I will need to convert the 12/24v signal to 120V? I was thinking a simple starter solenoid/relay from a car or boat would do the job maybe, if the temperature sensor would still be read by the motherboard but it probably has to turn off and on faster than that.

I also picked up some TMC2209 V2 stepper drivers, an E3D Titan extruder and bigtreetech TFT35 V2 screen.

I see on the smoothieware wiki they have calculations for the arms but its more for the programming. could you possibly send a link to the page you are talking about? Is there a rule of thumb for the effector? should it be as small as possible or a min/max size or anything?


Thanks for the input, its really appreciated

[AutoWiz]

I was thinking a simple starter solenoid/relay from a car or boat would do the job maybe...

MOSFET is the name of the correct part you need here. Because PWM circuits need to be solid state or they will wear out and fail. And solenoids are mechanical in nature so they will not respond well to the pulses of power. I personally am a big fan of the ones made by MKS as they seem to come with the largest heatsinks. You can also use one to drive a heater cartridge for your extruder if you like. They are cheap. Here is a fleabay ad for one: https://www.ebay.com/itm/3D-Printer-...UAAOSwv-ZZ5lXX

[Trakyan]

MOSFET is the name of the correct part you need here. Because PWM circuits need to be solid state or they will wear out and fail. And solenoids are mechanical in nature so they will not respond well to the pulses of power. I personally am a big fan of the ones made by MKS as they seem to come with the largest heatsinks. You can also use one to drive a heater cartridge for your extruder if you like. They are cheap. Here is a fleabay ad for one: https://www.ebay.com/itm/3D-Printer-...UAAOSwv-ZZ5lXX

You can actually use a solenoid relay, it uses what's sometimes called Bang-Bang control rather than a PID loop with PWM. It basically involves turning the heater fully on and switching it off as it approaches the target temperature, then switching it on as the temperature drops. It's a lot cruder and the temperature is less stable since the heater is either off or going full tilt, you can't turn it on just a little for fine adjustment. It is usable if you're on a tight budget like OP says they are, but they're also wanting to use profiled linear rails so that's sending some mixed messages.

[AutoWiz]

You can actually use a solenoid relay, it uses what's sometimes called Bang-Bang control rather than a PID loop with PWM. It basically involves turning the heater fully on and switching it off as it approaches the target temperature, then switching it on as the temperature drops. It's a lot cruder and the temperature is less stable since the heater is either off or going full tilt, you can't turn it on just a little for fine adjustment. It is usable if you're on a tight budget like OP says they are, but they're also wanting to use profiled linear rails so that's sending some mixed messages.

So for those who understand electronics when we energize a coil and then release the power what we get is a serious voltage spike. This effect is called a "collapsing field" and it is the stored energy in the windings of the coil quickly searching for a path to ground. It is also how spark plugs get their power to bridge an air gap in an engine's combustion chamber. It's how we can achieve Kv from 12v. By energizing a coil and then releasing the ground. And that collapsing field can generate so much power it can jump an air gap, or arc through plastic or an ignition wire if it needs to but that spike is so powerful it will find ground. To PWM or otherwise rapidly switch power to a coil is to constantly and repeatedly in fast or even a less fast fashion apply this affect to the controlling circuit. And it won't live long. We don't PWM solenoids or relays with coils. Solid State Relays ONLY for PWM, pal.

[Trakyan]

We don't PWM solenoids or relays with coils. Solid State Relays ONLY for PWM, pal.

My first sentence was saying that it does NOT use PWM.

[AutoWiz]

My first sentence was saying that it does NOT use PWM.

But slowly switching on and off IS pulse width modulation just at a slow frequency.

[Reefsider416]

You can actually use a solenoid relay, it uses what's sometimes called Bang-Bang control rather than a PID loop with PWM. It basically involves turning the heater fully on and switching it off as it approaches the target temperature, then switching it on as the temperature drops. It's a lot cruder and the temperature is less stable since the heater is either off or going full tilt, you can't turn it on just a little for fine adjustment. It is usable if you're on a tight budget like OP says they are, but they're also wanting to use profiled linear rails so that's sending some mixed messages.

Thanks, but i will probably just go with a mosfet because its more suited for the job. When i say I'm on a budget i just mean that I don't have an unlimited budget and if I wanted to spend a ton on a printer i would just buy one already made. I have several printers already so i don't want a cheap crappy printer that can just print. I want a really nice quality print and a large print volume and am willing to spend the money on things that make a difference like linear rails and maybe even genuine Hiwin or equivalent as I have heard they are worth the money. Its sometimes a challenge figuring out what will really be worth spending on but there are certain things I know will help. anything that makes it run smoother basically so belts, bearings, pulleys, stepper drivers, linkages etc will not be where i will look to save.

I just want to be smart about where i spend the money. A perfect example is the SKR board. It was like $30 CAD compared to a duet or others for $150-$300. I bought a clone E3D V6 but bought the genuine block sock and thermistor kit and hope to replace the heat break soon as well. I may stick to the 24V heatbed just to keep the costs down but may buy the 120v depending on how the budget is doing.

Power stuff I will stick to what is safe and made for the purpose. life span of electronics is related to proper power regulation as well as heat dissipation and duty load etc. I always use decent power supplies and components as it saves a lot of time and money in the long run.

[Trakyan]

I want a really nice quality print and a large print volume and am willing to spend the money on things that make a difference like linear rails and maybe even genuine Hiwin or equivalent as I have heard they are worth the money. Its sometimes a challenge figuring out what will really be worth spending on but there are certain things I know will help. anything that makes it run smoother basically so belts, bearings, pulleys, stepper drivers, linkages etc will not be where i will look to save.

Linear rails aren't bad, but I feel like it's a bit of a sledgehammer to swat a fly scenario. Lots of printers with round rails produce great results, even ones that are indistinguishable from those made on printers with linear rails. It's up to you, but I feel that many people go for linear rails because for the same reason they like to buy fancy cars. At the end of the day you're squirting molten plastic from a 0.4mm bore, and 0.2 is considered a good fitting tolerance, if your round rail can't hold that tolerance it's bent. The biggest practical advantage linear rails have on a 3D printer is that they can be fully supported, so on longer spans there isn't the bendy and flexible bit in the middle that can wobble under inertial forces (or sag if its not appropriated sized, but the rails on a delta are vertical so they wont sag).

This is even more so the case with idlers, pulleys and belts, the cheap stuff from china works fine and is manufactured to much higher tolerances than your printer will be outputting. Belts can sometimes cause problems from what I've heard with the rubber wearing off the belt, or not having fibre reinforcement but I've never run into these issues myself. Any difference someone claims between a chinese idler bearing and a name brand one is entirely in their head.

I just want to be smart about where i spend the money. A perfect example is the SKR board. It was like $30 CAD compared to a duet or others for $150-$300. I bought a clone E3D V6 but bought the genuine block sock and thermistor kit and hope to replace the heat break soon as well. I may stick to the 24V heatbed just to keep the costs down but may buy the 120v depending on how the budget is doing.

I don't know how much money, if any, you'll save buying a 24V bed vs line voltage, but at that size/power requirement I can virtually guarantee you'll spend more money than you saved on a 24V power supply that can handle that much current.

[AutoWiz]

Linear rails aren't bad, but I feel like it's a bit of a sledgehammer to swat a fly scenario. Lots of printers with round rails produce great results, even ones that are indistinguishable from those made on printers with linear rails. It's up to you, but I feel that many people go for linear rails because for the same reason they like to buy fancy cars. At the end of the day you're squirting molten plastic from a 0.4mm bore, and 0.2 is considered a good fitting tolerance, if your round rail can't hold that tolerance it's bent. The biggest practical advantage linear rails have on a 3D printer is that they can be fully supported, so on longer spans there isn't the bendy and flexible bit in the middle that can wobble under inertial forces (or sag if its not appropriated sized, but the rails on a delta are vertical so they wont sag).

This is even more so the case with idlers, pulleys and belts, the cheap stuff from china works fine and is manufactured to much higher tolerances than your printer will be outputting. Belts can sometimes cause problems from what I've heard with the rubber wearing off the belt, or not having fibre reinforcement but I've never run into these issues myself. Any difference someone claims between a chinese idler bearing and a name brand one is entirely in their head.


I don't know how much money, if any, you'll save buying a 24V bed vs line voltage, but at that size/power requirement I can virtually guarantee you'll spend more money than you saved on a 24V power supply that can handle that much current.

Man you are chock full of great advice. The linear rails get bolted to the frame every inch or so whereas the rods mount through holes only at the very ends of the rods and the entire length of rod can flex and the holes can get loose and then the rods themselves can move not the bearing against the rod. That is why we all upgrade to the linear rails. Because it stops the z wobble completely even with less than perfect leadscrews. You should just read more on this forum and try to limit the amount of advice you are giving here.