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Folger Tech 2020 Prusa i3 Build Log

Thanks! Besides TinkerCad, do you know any lightweight CAD design software that will run on a mid-range laptop? I have a tower computer I'm working on but I'm not so sure If it is worth repairing... And yeah I am hoping to print mostly in PLA, I like the idea that it is environmentally friendly so I will probably make a duct if I do get this kit. I read your blog btw, cool stuff :)
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Some guy in the desert
Thanks! Besides TinkerCad, do you know any lightweight CAD design software that will run on a mid-range laptop? I have a tower computer I'm working on but I'm not so sure If it is worth repairing... And yeah I am hoping to print mostly in PLA, I like the idea that it is environmentally friendly so I will probably make a duct if I do get this kit. I read your blog btw, cool stuff :)
I do almost all of my cad work in openscad. It's not for everyone...but I find it easier to use for some things than traditional CAD. And it runs on really low end hardware. TinkerCad is barely usable on my main computer but openSCAD runs fine. Really a lot of the concepts are the same as traditional CAD just the interface is different. I originally learned CAD on an original IBM PC with no mouse so entering measurements to move things around is still ingrained in my mind. Though modern CAD really is nice for a lot of things the parametric code driven design of openscad works well for me since I do a good bit of programming as part of my day job :)
I downloaded and tried both of these, but both of them are too advanced for me. I know next to nothing about CAD, I will keep looking though, trying FreeCAD next
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Thanks everyone, Fusion360 is actually running pretty well for me, and it's not too advanced.

One question about the printer itself though, is it possible for this printer to create prints that are as high quality as the "original" prusa i3 mk2?
Thanks everyone, Fusion360 is actually running pretty well for me, and it's not too advanced.

One question about the printer itself though, is it possible for this printer to create prints that are as high quality as the "original" prusa i3 mk2?
It's really about how rigid and square your motion axes are. If you can get everything dead square and stiff, then you are on the right track to good quality. People get pretty good quality out of that printer through careful assembly and some basic upgrades. Switching out the threaded rod for lead screws is a popular change.

From there you would need to improve the heated bed (Prusa printers have a custom PCB heater) and the extruder assembly (feeder and hot end).
Were you able to get fusion360 for free?

*Edit* Never mind, it requires 64-bit windows, which I don't have. Any other suggestions for an easy to use cad program?
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Were you able to get fusion360 for free?

*Edit* Never mind, it requires 64-bit windows, which I don't have. Any other suggestions for an easy to use cad program?
Try onshape! It's free and browser based, although you can't have private files, everything is shared on their service.

Probably won't be getting the Folger kit anymore, too expensive in Canada (Would be almost $600 cad!) Im looking at an Amazon.ca listing to a Wanhao I3 which is about the Same price as the Folger kit itself.


Some guy in the desert
Well, started some upgrades on my printer last night so figured I should bring this thread back to the top :) (maybe we can even get a mod to move it into the 3D printing section now that we have a 3D printing section ;) )

I've been super happy with my printer over the past year. In fact I've had the parts for this upgrade sitting here since last March and just haven't installed them because I haven't wanted to have any down time on the printer and it's been working so well.

But the past few weeks I've been working on trying the new 1.1.x release of Marlin and it's got me really frustrated. I've had a few minor bed leveling issues that I was hoping it would help clear up...but only made worse. Really they're mechanical in nature though and this Y upgrade should help with them. Plus the Y axis has never been quiet but has gotten even louder lately. So time to finally install these new parts.

First step - there was one semi-optional part I had yet to print...and since it was likely to stiffen up the bed and help with some of the leveling issues I figured I should go ahead and get it printed first. Details about that process here: http://forum.flitetest.com/showthread.php?33284-3D-Printing-fails&p=345561&viewfull=1#post345561

Then I realized that with all the parts sitting for over a year I had used some of the hardware on other projects. So...quick trip to the hardware store to pickup a bit of M4 hardware.

With all that sorted out I first finished another little upgrade - a new spool mount because the stock one was getting annoying and starting to sag:


Haven't printed with it yet...but I think it's an improvement. The first spool I plopped in doesn't fit as well as I'd like...not sure if it's the spool or the roller though. Basically the spool sides aren't parallel so it rubs a bit while spinning. Should work just fine but it's not quite as quiet as I expected due to the sides of the spool rubbing. We'll see how it does with some other spool soon.

Then...took a deep breath and dug in on tearing down the Y axis and putting in the new parts:

This is basically just a mockup at this point...but I'm pretty excited. The openbuilds parts move much quieter than the stock rails and it seems smoother. I'll also be able to finish installing the belt and get it all tensioned up before I have to mount it - so the axis is much more modular. Plus I expect it will stiffen up the whole machine and help keep things more square. I figured this would be a nice upgrade and the more I work on it the nicer it seems!


There's that giant print that gave me so many headaches finally in place. Removing the stock folger parts I was amazed at how bad the quality on them was. I had forgotten just how poor they were since most of the visible stock parts I had replaced some time ago!


I have to drill 4 new holes in the bed support...as if it doesn't have enough holes already! Thankfully most of those will no longer be needed.

So tonight I'll get those holes drilled. Install the timing belt and mount it all up. Hopefully I'll be back in action in just an hour or two.

Then I may have to try and dig up a piece of glass I can cut a 200x300 piece out of since this longer Y axis will let me use a larger bed ;) I won't actually have a heater for that bigger piece...but some blue tape should make it suitable to finally finish printing that hovalin for my wife that won't quite fit on the bed :D

I'm also starting to think about the X axis now...there's a similar upgrade for it I may pursue. Though that has me also thinking about the Z and the possibility of getting rid of the linear bearings/rods there as well...hmmm


Some guy in the desert
I should have done this a long time ago!


Wow, what a nice upgrade. 98% of the rattles the machine made are just gone. There's still a tiny tiny rattle from my binder clips sometimes...and the Y stepper is a little louder than I expected but I can probably turn it down a bit more now since the Y axis moves so much easier now. I also noticed I'm still running a stock stepper driver on the Y axis so it's only at 16 microsteps...I still have some spare upgraded drivers so I could pop one of them on there which would make it quieter and then quieter again if I jumped it up to 32 microsteps. Might have to try that tomorrow.

This was easier to assemble, square and adjust than the stock parts. The machine is stiffer, the bed is stiffer, it's quieter...just...all win across the board!

I also finally put some cork under the heater while I was at it...but need to come up with a way to attach it to the bottom of the bed...I'm hesitant to use glue or tape since that seems likely to make a huge mess given the heat situation. It's better than nothing having it in there but I'm sure it could do better.


The one complaint I still have is bed leveling. I'm really thinking I need to break down and get an aluminum bed. Or a bltouch. I added an extra sheet of HD aluminum foil and the M48 tests still look great...but my bed leveling results still seem odd:

5:14:26.929: Bed Level Correction Matrix:
5:14:26.929: +1.000000 +0.000000 +0.000375
5:14:26.929: +0.000000 +1.000000 -0.000179
5:14:26.932: -0.000375 +0.000179 +1.000000
5:14:27.752: X:187.00 Y:170.00 Z:2.39 E:0.00 Count X: 14960 Y:13600 Z:1941

That's after I leveled it manually and all four corners and the center felt "equal" to me using the piece of paper under the nozzle test.

What's odd is that +1 diagonally across the bed. The rest is pretty much on...but why I get that is beyond me. I tried turning those corners down and even with a big change on the corner adjustments got the same basic results. So I have to assume it's something causing my probe to get false readings in those locations.

M48 tests of my sensor look good to me:

5:42:19.688: M48 Z-Probe Repeatability test
5:43:18.012: Mean: 1.396500
5:43:18.037: Standard Deviation: 0.000750
5:43:18.066: X:137.00 Y:100.00 Z:2.40 E:-1.00 Count X: 10960 Y:8000 Z:1918

(Front Right corner)
5:44:22.505: M48 Z-Probe Repeatability test
5:45:21.484: Mean: 1.462625
5:45:21.509: Standard Deviation: 0.001038
5:45:21.538: X:170.00 Y:0.00 Z:2.46 E:-1.00 Count X: 13600 Y:0 Z:1970

(Front Left Corner)
5:46:19.636: M48 Z-Probe Repeatability test
5:47:18.603: Mean: 1.440875
5:47:18.628: Standard Deviation: 0.000800
5:47:18.656: X:50.00 Y:10.00 Z:2.44 E:-1.00 Count X: 4000 Y:800 Z:1954

(Back Left Corner)
5:47:49.166: M48 Z-Probe Repeatability test
5:48:48.363: Mean: 1.234125
5:48:48.391: Standard Deviation: 0.000800
5:48:48.416: X:50.00 Y:170.00 Z:2.23 E:-1.00 Count X: 4000 Y:13600 Z:1787

(Back Right Corner)
5:50:09.183: M48 Z-Probe Repeatability test
5:51:08.203: Mean: 1.401250
5:51:08.228: Standard Deviation: 0.001118
5:51:08.257: X:187.00 Y:170.00 Z:2.40 E:-1.00 Count X: 14960 Y:13600 Z:1921

That back right corner isn't great...but they all seem fairly close. A friend who uses a servo mounted endstop for leveling and says he never has any issues gets a standard deviation in the 0.02 range so I seem way more consistent. Which is why I suspect it's what my sensor is triggering off of more than my sensor itself and why I want to try an aluminum bed.

I could definitely adjust my z offset a tiny bit still since I'm asking for a 0.3mm first layer and getting 0.4 But it's an even .4 all across the bed and measuring that bed test I just printed all locations are within 0.01mm of each other - which is within the range of error of my calipers so tough to do much better :D

So a bit of room for fine tuning still but already seems like a huge improvement. Need to get a few prints done and then maybe I'll get silly again and try 1.1.x one more time....
I printed a very similar spool holder for my FT-5, I found it made a big difference since I was having issues with missed steps/layer shift because of the filament binding up. Works really well for me.


Some guy in the desert
I printed a very similar spool holder for my FT-5, I found it made a big difference since I was having issues with missed steps/layer shift because of the filament binding up. Works really well for me.
Yeah bearings help a lot. Adding the bearing mounts to the original sidebar solved 99% of my filament issues. But sometimes some rolls would still start to unwind and get tangled - so I added a popsicle stick taped to the side support that would rub against the bottom of the spool. Ugly as sin but solved 99% of the last 1% of my issues. Every now and then something would still sneak past it but very very seldom. This design seems like it should be immune to that. It is a bit louder due to the spool rubbing against the sides sometimes but overall I'm liking it.

I've had this one marked since I got the printer...but since it needs the flanged bearings I've never bothered to try it:

And I really like this one...but wouldn't work well mounted above, I don't have room for it anywhere else (and I wanted a top feed) plus I suspect it's a bit noisier ;)


Some guy in the desert
Just a heads up since I'm loving this Y upgrade so much. Openbuilds is having a free shipping event today only. I just took advantage of it to order the parts to do the matching X upgrade: https://www.thingiverse.com/thing:1285301

Though I'm thinking about some changes on the X upgrade...I didn't order the plate since it's available as a CAD file and I want to redesign my extruder (I've been wanting to switch to a geared extruder for some time) ... so I'm thinking about designing something more like this version: https://www.thingiverse.com/thing:1939056 Where the extruder stepper is over the top of the rail and the extruder extends down in front - with the extruder body incorporating the plate.

Anyway, point is if you've been considering doing this upgrade I highly recommend it and with free shipping it's a great time to pull the trigger and make it happen :)


Some guy in the desert
Wow, openbuilds blows me away again. Took advantage of their one day free shipping sale on Friday - today when I went home for lunch there was a box from them waiting!

NJ to AZ in one business day...for free :)

Unfortunately I haven't finished printing the parts for the upgrade or designing my new extruder!

I did get the extruder body redrawn in Onshape:

Screen Shot 2017-05-22 at 2.34.06 PM.png

Only took me about 2 hours, so I guess I'm getting better with Onshape :)

It's basically the exact same as the one I built a year ago (From Thingiverse: https://www.thingiverse.com/thing:725082 ) and have yet to install...except I filleted a few of the edges, and since it's drawn in Onshape instead of openscad it's a lot easier for me to manipulate now.

I just debating how I want to go about attaching it. I could just make an adapter plate to go between the stock mounting of this extruder and the openbuilds mini gantry...but since I printed my gantry that seems silly. So Instead I plan on modifying this part to include the gantry plate so wheels will attach directly to the extruder with no separate plate. I just haven't decided yet if I want to keep the gantry vertical like the current mount - or try and work a way to put it in horizontal so more of the extruder is over the top of the X axis instead of cantilevered out front.

Here's a really rough mockup of what I'm thinking:

Screen Shot 2017-05-22 at 2.39.58 PM.png

The plate is just kind of jammed in there for now, and I'd have to remove all the stuff under it...but I think it has potential.

The other issue I still have to figure out...and the reason I never installed that extruder - is how to mount both a layer fan AND my inductive probe. I have a few ideas...but I'm going to have to figure out the basic mount plate first and then print and test assemble this thing to see how viable they are.

But I still have one more piece for the basic X axis to print and all of them need a little bit of massaging. The openings for the 20x20 rail are sized at 20.3mm with a 1mm fillet in the corners. My rail measures 19.97mm with my calipers and the actual printed opening measures about the same...but that fillet in the corners gets in the way. So either I need to redesign the parts or do a bit of work with a file on the ones I've already printed. The guy who originally designed the parts said he shared them on onshape but I can't find them...so I'd have to redraw them from the STL's or the one STEP he shared on Thingiverse....hmmmm


Gravity Tester
Today I received a package with a fresh roll of Hatchbox filament. It's actually only my second kilogram of filament :eek:. How could that be? Well I print mostly small parts and rarely anything large. I am also away at college and without my printer for many weeks of the year. So finally on to the second spool. I got black this time instead of white (I know I am super colorful with my choices).

I also picked up a 50g 'splash spool' of Sainsmart TPU in blue. I only got 50g because I am unsure how the printer, and specifically the extruder, will perform with the TPU, and I also don't anticipate printing a whole lot in TPU just yet.


Skill Collector
A quick note of warning on this particular machine or any that uses a RAMPS 1.4 or 1.5 board.

My FolgerTech i3 Prusa melted a power connector - complete with smoke and plastic dripping this week.

Seems the screws on the green power connector where the primary power comes into the RAMPS board tend to rattle themselves free in a couple months. As the screws loosen, the power connection gets looser creating higher electrical resistance and increased heat at the junction.

I was alarmed when the smoke started coming out of mine but even more alarmed when I searched on the net and found I wasn't the only one with this issue by far. The real recommended fix is to remove the green screw down connector and direct solder the power leads to the RAMPS board, which is what I'll be doing when my new board comes in.

Just wanted to make everyone with this machine aware - either check those screws for tightness every week or two, or change out that connector. I'll upload a picture of the nice melted mess it made when I get back home today.


Some guy in the desert
Yeah, those green power connectors on RAMPS are horrible. They aren't even rated for the current that the board can draw with the hotend and heated bed running, so even if the screws don't come loose you can have a meltdown. The protection circuits aren't great either - a lot of people replace them with automotive fuses for security as well.

My upgrades have been a little stalled out. I got all the parts from openbuilds for my X but have run into some issues printing the printed parts for the X upgrade. I've been slacking posting about it because the bulb in my good lamp died so it's tricky to get detailed photos of the black filament I've been using...so please excuse the photo quality in this post, I hope to get a new bulb this weekend so I can get back to my usual quality ;)

The problem is the parts are almost all designed to be printed with supports...LOTS of supports. And frankly I've never had a ton of luck with slic3r's supports and PLA. With ABS - no problem, supports pull right off. But with PLA or PETG - they never come off cleanly.

The tanish piece was my first attempt, printed as it's sitting with full supports. Removing them was a major pain...and I still didn't get them all. I could make the piece work but it would be ugly.


So I decided instead to try rotating it 90 degrees to the right and printing it with supports only on the bed. This is the orientation I next tried printing the pieces in.


That worked better...but the inside of the square section of course wound up with one side that wasn't great since it was all bridged.


I could probably get it cleaned up and get the V rail in there...but wanted to do better...So tried redesigning the part in Onshape so it could print without supports but would give up a bit of constraint on the V rail:


The photo doesn't show it great...mostly shows off the way I filleted the part to make it smoother and fit my aesthetic better. But if you look closely you can see that the back is now a J shape that loops over the rail and has holes to attached with T nuts on two sides.

That worked...and test mounting it I was pretty sure it would work:


Except....I forgot that the belt has to pass through the groove on two opposing sides. So T nuts on sides 90 degrees apart isn't an option. Crud. I had also opened up the square section for the V-rail a bit more the original design was 20.3mm on both dimensions and was SUPER tight, I opened it up to 20.5 but had a bit more slop than I liked.

On on the next revision I shrank it down to 20.4 but still had a tiny bit more slop now that I didn't have to try and get it to clear on all four sides. I also removed almost all of the 3rd side since the mounting holes over there were worthless. And finally I further refined the overall shape a bit more for cosmetic purposes:


But - with that 3rd side that short and still having a bit of slop I just don't trust it. Even though it feels good once I tighten up the T nuts on the top I worried that they could come loose over time and cause an issue. So I tried another revision with the opening down to 20.2 (smaller than the original!) It needed support again but with one side open I figured it would be easier to cleanup:

Screen Shot 2017-05-26 at 9.59.00 AM.png

Well, there's a reason I only have a rendering to show. The supports failed and caused the whole print to fail :( And the bits that did come out showed that 20.2 was probably too tight. So...back to the drawing board.

I went back to the J shape, and decided to keep both sets of holes even though only one can be used at a time. That was the same parts could be used whether the gantry is mounted on the front or top of the rail. The original design puts it on the front with the extruder cantilevered off...but some people have done designs with the gantry on top which I prefer since it puts more weight over the rail instead of hung off it and it makes for more Z clearance. I kept the tight 20.2 spacing since this is only constraining the V rail on 3 sides...I may have to revisit that...but since this will print without supports again I think it will do better, I haven't had time to try printing this version yet though:

Screen Shot 2017-05-26 at 9.45.28 AM.png

You'll notice I also simplified the bearing retention to make it easier to print. Honestly I've been running my printer for a year and a half without even installing the screws on that part since the bearings are held so tight even without them...and I confirmed that this design does just as well. In fact the only reason I kept the Tabs is so I can use a screwdriver to wedge it open to make installing and removing the bearings easier. I left the holes for the screws in case anyone else wants to use them but I won't be bothering again.

I'm hoping to print this tonight and am quite hopeful that it will work. I think with 3 sides constrained and the two T nuts it will be retained well enough for me to trust it.

I've also been working on tweaking the tensioner setup. My first take on it was almost purely cosmetic, though I did open the inside up just a TINY bit so the V rail would fit easier and so the tension slider could move more easily. The tan version is the original, the black is my first redesign:


The original design attaches with 2 3mm screws in T nuts. But since this is the tensioner it's under tension and I worry that that wouldn't hold up to the tension. So I added a bit more material on the sides the belt doesn't run on so the part had shoulders that would rest against the edge of the V rail and keep it from sliding under tension:


That seemed to be an improvement. Except the extra material took up enough room that the tension slider only had 1 or 2 mm of travel now :(

So...one more revision which I haven't had time to print yet:
Screen Shot 2017-05-26 at 9.45.07 AM.png

It's a little longer and I rounded over the shoulders so they don't take away as much travel. This should allow for 10mm of travel by the tension slider. Where the shoulders meet the verticals it's a little wonky...but I can live with it.

It all looks pretty good in a full mockup:
Screen Shot 2017-05-26 at 9.45.50 AM.png

I've also done a bit more work on the extruder...but ran into an issue there. I forgot about the gear. I haven't figured out how to draw the herringbone teeth yet...but got the gear mocked up enough to check for clearance issues...and realized that hanging the extruder off the front of the rail is going to be harder than I expected due to the gear:

Screen Shot 2017-05-26 at 10.16.36 AM.png

So at this point I'm looking at either just attaching it to the front like I wanted to avoid...or completely redesigning the extruder. Not sure what I'll do there yet.

Of course since I'm doing all this in Onshape the files are public and anyone who wants to can copy them and make their own changes:


Rail mount:



Should also have a new aluminum bed arriving today which I'm curious to see if it will stiffen the bed further and give me more consistent probing with my inductive sensor. If not...well I can build a mount to put it on my MPCNC and have an easier to level bed on there so I can start using it as a printer as well :D


Gravity Tester
I'll have to check out my green connector. I don't use my heated bed very often so I don't think I've put much stress on it, but doing a direct solder may be a good idea.

I've been really think about doing the Openbuilds V rail upgrades, but first I am going to get some lead screws and raise the Z axis up. I may also consider an extruder upgrade in the future, but one step at a time :p
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