How exactly do GT2 belts fix this ? I run GT2 belts and pulleys... and it doesn't seem to offer any magical 'fix'.. just a different Pitch...
The Big difference between the GT2 belts and pulleys and the stock SD3 belts and pulleys is the shape. SD3's use a square shape and if you have any play between the belt and pulley teeth you will get a slip when the Axis reverses. With the GT2 belts you have rounded teeth allowing the belt to sink into the pulley creating a snug fit and no slippage. _carbondrivesystems_com this is a perfect example of the GT2 concept.
Why would you switch to GT2 belts and pulleys if there is no improvement?
I understand how the Bed works, I'm not saying to remove the beds ability to compress to keep the print from popping off the bed. If you give the bed some type of guide allowing the bed to return to it's original position after compressing would only make things better in my mind.
Yes what I am doing is probably overkill, but it's fun and I may learn something along the way.
]]>Going with the GT2 belts a pulleys will fix that.
How exactly do GT2 belts fix this ? I run GT2 belts and pulleys... and it doesn't seem to offer any magical 'fix'.. just a different Pitch...
another thing I've noticed is the Plate or Bed needs attention. with the current design, if you get a build up of plastic and the head hits that bump, the plate will shift,depress and then rebound with little chance of returning to the same place because of the poor design thus you will get shifts in the part. I need to come up with some type of guide for the plate.
Thats precisely how it is supposed to work - otherwise when you hit a piece of over extruded print on a perimeter halfway up a model, it would just knock the model clear off the print bed. Or crash the head. Or Crash the bed.
Despite appearances - there is very little 'issue' with the bed other than perception of issues... Its a well tried and true method of running printer beds... And it does return to the same spot pretty much - no where near is this enough of an issue to cause ongoing quality concerns...
Anyway.. continue on with the rebuild.. but I think now you could be accused of slightly starting to over think the quality issues... Perception doesn't always match reality when it comes to how printers work, and what provides the 'best' quality.
]]>have you followed the steps for x/y calibration? that's what determines circle accuracy, not machine rigidity, for the most part at least. you would be surprised how accurate these little machines can be if you take a few hours to really dig into the settings and get everything 'perfect'.
my comment on designing your own printer was a bit misguided. i guess i should have recommended something like the rostock delta printer design, im currently collecting parts for one myself. benefits are extremely low mass of the print head that allows for much faster print speeds than a SD, or any other xyz style printer. and almost double the vertical build area (around 16 inches) and the ability to print outside the bounds of the print bed, something xyz printers cant do.
i think the design would lend itself nicely to being machined out of aluminum, as long as you take care to cut out dead weight areas that don't contribute to strength. which will actually be most of the part. haha.
I tried all the calibration and adjustments that I could find. The thing that I found most detrimental to creating a accurate circle was the belt shifting when the Y axis reversed direction. Going with the GT2 belts a pulleys will fix that. another thing I've noticed is the Plate or Bed needs attention. with the current design, if you get a build up of plastic and the head hits that bump, the plate will shift,depress and then rebound with little chance of returning to the same place because of the poor design thus you will get shifts in the part. I need to come up with some type of guide for the plate.
I'm not thinking rigidity and speed so much as quality and durability. I completely agree with you that getting all that mass off the print head would by far be the best situation. I may have to look into this printer you mentioned and make some modifications to my build.
I just had a thought, I'm wondering if they make hollow rods at 8mm? that would shave allot of weight.
]]>I'm not looking for that type of accuracy either, but at its best my machine printed circles that had a difference of about .5 mm to me that was unacceptable. try putting a micrometer to your circles I bet they aren't as good as you think. But if your happy with your SD3 that's all that counts.
When it comes to mass, the majority of it is wrapped up in the steel rods and stepper motor for the extruder. I don't think the few extra grams I add will make a difference. Also since I am going with bearings motor life should be extended. If I really want I could remove enough Aluminium and make them as light as the printed parts, which I may do once I've created the first prototypes.
I like the Idea behind the SD3 because it is kind of modular, you could increase the size of the printing area and reuse most of the parts. that was my idea after I finish making my parts. New rods wire extensions and a carbon fiber cage, job done.
have you followed the steps for x/y calibration? that's what determines circle accuracy, not machine rigidity, for the most part at least. you would be surprised how accurate these little machines can be if you take a few hours to really dig into the settings and get everything 'perfect'.
my comment on designing your own printer was a bit misguided. i guess i should have recommended something like the rostock delta printer design, im currently collecting parts for one myself. benefits are extremely low mass of the print head that allows for much faster print speeds than a SD, or any other xyz style printer. and almost double the vertical build area (around 16 inches) and the ability to print outside the bounds of the print bed, something xyz printers cant do.
i think the design would lend itself nicely to being machined out of aluminum, as long as you take care to cut out dead weight areas that don't contribute to strength. which will actually be most of the part. haha.
]]>FYI, today I was making up a bunch of these, and they all came out just fine. True in all dimensions.
]]>my printer aces the nickle calibration every time, and i run it about once a week. haven't touched the bed leveling screws in a month (but i did do the thumb screw mod, so my bed screws are tightened down quite a bit).
i don't know if im just lucky to have the most accurate SD3 in existence, or if the machine is just set wrong from the factory and i found the right combination to tweak it.... or perhaps im not looking for .00001" accuracy from my circles.
but i don't see the need for all this upgrading. to me it would just make the moving parts heavier and cut down on motor life + increase stresses on all parts while printing, and cause inaccurate perimeters due to increased mass of the carriages resisting direction change. perhaps im over thinking it, but that's just my .02.
why not design your own 3d printer since you have the means to? why stick to the SD design if your replacing all of it? lol
I'm not looking for that type of accuracy either, but at its best my machine printed circles that had a difference of about .5 mm to me that was unacceptable. try putting a micrometer to your circles I bet they aren't as good as you think. But if your happy with your SD3 that's all that counts.
When it comes to mass, the majority of it is wrapped up in the steel rods and stepper motor for the extruder. I don't think the few extra grams I add will make a difference. Also since I am going with bearings motor life should be extended. If I really want I could remove enough Aluminium and make them as light as the printed parts, which I may do once I've created the first prototypes.
I like the Idea behind the SD3 because it is kind of modular, you could increase the size of the printing area and reuse most of the parts. that was my idea after I finish making my parts. New rods wire extensions and a carbon fiber cage, job done.
]]>foofoodog wrote:dkeeling728 wrote:why not design your own 3d printer since you have the means to? why stick to the SD design if your replacing all of it? lol
I tend to agree. But it comes down to this, if it ain't broke don't fix it. For him it may be broken, for others not so much.
I would like to take note that this forum has a huge emphasis on upgrades and replacing the stock parts with custom modifications, all of which is what this guy is doing except he is using machined aluminum and market bearings instead of 3d printed parts. If you knock his effort, you are also saying that Ian, lawsy, and adrian have been wasting their time here.
I would amend that statement to: If it ain't broke, prepare for the worst and print a set of replacement parts...
Truthfully, I'm looking at building a larger scale solidoodle using printed parts and aluminum extrusions for the frame. It's all a matter of what you understand, and I understand "Solidoodlese," so that's what it will be based on. He has a machine shop, therefore he will be building off the design as well in aluminum. If I had a machine shop, you bet that I'd be doing the same thing. Heck, if I had the tools, I'd print in PLA and cast in aluminum. Either way, I'd be getting more solid parts.
]]>dkeeling728 wrote:why not design your own 3d printer since you have the means to? why stick to the SD design if your replacing all of it? lol
I tend to agree. But it comes down to this, if it ain't broke don't fix it. For him it may be broken, for others not so much.
I would like to take note that this forum has a huge emphasis on upgrades and replacing the stock parts with custom modifications, all of which is what this guy is doing except he is using machined aluminum and market bearings instead of 3d printed parts. If you knock his effort, you are also saying that Ian, lawsy, and adrian have been wasting their time here.
]]>why not design your own 3d printer since you have the means to? why stick to the SD design if your replacing all of it? lol
I tend to agree. But it comes down to this, if it ain't broke don't fix it. For him it may be broken, for others not so much.
]]>i don't know if im just lucky to have the most accurate SD3 in existence, or if the machine is just set wrong from the factory and i found the right combination to tweak it.... or perhaps im not looking for .00001" accuracy from my circles.
but i don't see the need for all this upgrading. to me it would just make the moving parts heavier and cut down on motor life + increase stresses on all parts while printing, and cause inaccurate perimeters due to increased mass of the carriages resisting direction change. perhaps im over thinking it, but that's just my .02.
why not design your own 3d printer since you have the means to? why stick to the SD design if your replacing all of it? lol
]]>- Bump the jack shaft up to 8mm instead of the 6mm that it uses now. http://www.adafruit.com/products/1252
- Make the hotend more accessible. That drawing makes it look like you have to take the x-carriage apart to get the hotend out. It might just be low detail keeping me from seeing seems.
- Pirvan posted his lead screw mod Here. It's a good mod but I think small bore threaded rod would be just as good and cheaper.
I will be interested in seeing how this comes out.
]]>I wnt to offer you a suggestion: Fix that bed too. As it is now, the way the aluminum angles upward and the leveling screws are like three long stilts that just wave all around. One little blob in the middle of a print knocks the entire bed off course. Not only can it shift, it can also twist. If you are going to put linear bearing on the Z axis rods, you need to fix the leveling design also to make it worth while.
I agree with you that the Plate or Bed needs some attention, that is why I added the stiffeners with linear bearings. when I had my SD3 apart I noticed the the rivets on the Bed were lose, allowing the bed to twist slightly with little force.
Because my design will be much stiffer than the original I want to allow as much spring as possible. Maybe some type of linear sliding posts that only allowed for up and down motion and restricted twist and X Y movement.
The Z axis upgrade is much more accurate than the original and Including anti-backlash nut it only costs 46 USD.
I agree if you stay on top of your SD3 maintenance wise you get nice looking prints but I want better and as maintenance free as possible.
]]>The reason Why is easy enough, the SD3 just isn't accurate especially when it comes to circles.
I do not see that problem with mine, though I have only run about a kilo through it.
The shapes in this (poor) picture come out true with the default three tenths slic3r. A one tenth slice would be finer.
For my own purposes, so far, even as much as 1/4 mm slop is no big deal.
I wish you luck.