Folger Tech 2020 Prusa i3 Build Log

[jhitesma]

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

The Y rail upgrade has been GREAT. I can see a difference in my prints Y vs. X axis now. There's noticeably less ringing in the Y axis than the X...and it's SO MUCH quieter now. I need to revisit the modified accelration/jerk settings I was using when first trying Marlin 1.1.x that had almost eliminated any ringing on both axes. I also need to adjust the belt tension on Y as it's stretched a bit after a week or two of use and is a little sloppy now, but that means taking the bed off and that would mean rebuilding my UBL mesh and I haven't felt like dealing with that yet. Once the aluminum bed arrives it will be worthwhile to make the change I figure. Just not sure if I'll still use glass with the aluminum or not...I can't afford to put PEI or Kapton on it right now and don't want to print directly on the AL...so I'll probably keep the glass for now. But it will mean giving up 3mm of vertical height (which I basically never use.)

If you do the lead screws get the anti-blacklash nuts...they weren't available when I did mine and I wish they were because I do have a bit of backlash that affects my Z on some prints. I just ordered a set which I plan on installing when the new X parts are finished.

The extruder upgrade...honestly it was probably the worst upgrade I've done. I got better quality prints with the original MK8 style extruder and the $10 aluminum extruder body with adjustable tension I got off ebay. The reason I "upgraded" was to get the higher temp range of the v6 hotend so I could do PETG better and Nylon (maybe someday even try polycarbonate). The new extruder is also better for flex since it has more constraint. There are ways to mount the V6 to the original plastic extruder...but the original plastic didn't work well for me since the pivot was wallowing out and it didn't have adjustable tension - and the design of the aluminum version had no way to mount a V6 hot end. I really wish I could find an aluminum mk8 with adjustable tension - but without the big aluminum block on the bottom that prevents installing a v6.

I'm looking at moving to a geared extruder to lessen the forces on my extruder stepper since it runs hotter than any of my other steppers. Just been a low priority change since what I have now works.

I may just redesign what I have now to mount better on the V rail and to shorten the distance between the drive gear and the hotend which is my biggest complaint about it and what I suspect is the cause of the slight drop in quality I've experienced since it's less direct of a direct drive and more like a solid bowden that's only 1.5" long.

 

[jhitesma]

Latest round of design changes to the modification parts are looking great!



The new motion mounts fit perfect, no slop and not too tight and they print wonderfully with no support. There isn't really any force pushing up against them in use (unless the head crashes in which case I've got bigger problems) so I don't think having the bottom unconstrained is going to be a big deal.



Latest Tensioner came out wonderful as well:



I forgot about the hole through the "top" part that printed as a bridge...that caused a few dropped passes of filament...but i printed with 4 perimeters so it still came out good enough. Fits great, looks great, can no longer slide, and there's still plenty of room for the adjuster to travel. The bit that looked goofy in CAD printed just fine so not even worried about that!

Still not sure why this black sometimes prints glossy and sometimes matte even at the same temp...and not sure I really want black for these parts...I'm kind of going to miss the pink on my machine the current parts are printed in. I don't really have any other unusual colors to use...I do have some translucent blue that would go great with the blue PETG on the Y axis...or I could use my translucent red...but will probably just use these because they're good enough.

The only part I haven't redesigned is the X stepper mount...and not sure I'm going to. It printed well enough I think it will work...this black just didn't bridge as well as the tan did but I ran out of tan. Then again it may be nice to just to round it over to match the other parts. We'll see how bored I get.

I could conceivably install this today...but I'm still waiting on some anti-blacklash nuts for my lead screws that I want to install at the same time so I don't have to tear the whole machine down again. And I want to reprint my motor risers because my current ones have a few layers delaminating and I don't trust them. (They were printed in ABS right after I got the machine and I didn't really have things dialed in very well yet...plus that particular ABS is pretty much junk. It's the pink and I still have most of a roll of it but it's hands down the worst ABS I've used.)

So probably going to work on my extruder ideas this weekend more than anything else related to this. But big project is to take advantage of my wife and daughter going on a girl scouts field trip and get my shop cleaned up

 

[rockyboy]

That new rail setup is looking very solid. I'm still waiting for the new RAMPS board to be delivered. Here's the pic of the melted power connector to watch out for.

Please everyone who is using these boards go tighten up your screws right now. I was very lucky there wasn't anything flammable near by when this shorted itself out. Don't rely on luck for this.

 

[jhitesma]

You should be able to just unsolder that connector and solder your power wires right to the board. It's better anyway. Like I said even with the screws tight that connector isn't rated for the power the board puts through it. Just a poor design choice from the get go.

Haven't made much headway on the printer today...may install the new aluminum bed tonight but that's about all I plan on doing.

Did make some progress on the MPCNC - finally cut the conduit for the center span supports I printed like 3 months ago. But that's a different thread

 

[dkj4linux]

That new rail setup is looking very solid. I'm still waiting for the new RAMPS board to be delivered. Here's the pic of the melted power connector to watch out for.

Please everyone who is using these boards go tighten up your screws right now. I was very lucky there wasn't anything flammable near by when this shorted itself out. Don't rely on luck for this.

View attachment 88331

Rockyboy,

I had the exact same thing happen to me 2-3 weeks ago and was pretty certain that it wasn't component failure or a short (it had been working perfectly just minutes before) but simply because I was adding a part fan and associated wiring to my printer and figured I must have bumped/moved something...

http://forum.flitetest.com/showthread.php?33284-3D-Printing-fails&p=344972&viewfull=1#post344972

I simply removed the melted connector and wired directly to the terminals on the board... as Jason has also suggested. I've printed numerous parts since... without failure and/or RAMPS overheat or malfunction. If yours had been working fine up to the time it fried, I'd give that a try... see my post above for pictures of the repair.

-- David

 

[rockyboy]

Thanks David! Maybe my old board isn't fried after all - while I'm waiting on the delivery man for the new board, I'll see about removing the connector and trying my old board one more time. Might get me up and printing quicker!

 

[Snarls]

Printed in TPU for the first time today, the only other filament I've used being PLA. It is Sainsmart brand TPU and is not as flexible as some of the stuff I've seen with Ninjaflex, but it is definitely flexible. I was concerned with how the stock extruder on the Folgertech 2020 was going to do with the flexible filament so I dialed down the speeds to 15mm/s. Also per recommendation by Maker's Muse on Youtube, I disabled retraction and set the temp to 230C first layer and 220C for the rest. I did not want to fiddle with the heated bed so I decided to try printing on blue painters tape with some glue stick as I usually do with all my PLA prints.

I started my first print and thought the extruder was jammed. Turns out everything was fine and the translucent blue filament is just hard to see on blue painters tape. After a couple intense minutes my first TPU print was done:



Success! It's a motor mount for my TBS Discovery. Not because I'm getting on the soft mount bandwagon, but because I want to test the vibration reduction possibilities of TPU and hopefully improve my video. This picture is after cleaning the part up. Because retraction is disabled the print ends up with strings everywhere the extruder crosses from one area of the part to another. I also find TPU oozes out of the nozzle more than PLA when just sitting.

Now to have some more fun with this TPU before putting the PLA back on. I only have a 50g 'splash' spool, so I don't have the capacity to print anything too demanding just yet.

 

[rockyboy]

Thank you David & Jason - turns out the board wasn't fried, just the connector. I'm soldered direct and everything is printing fine again.

Snarls, I haven't tried any flexible printing stuff yet, but that looks like it was pretty simple for good results. Might be time to order up some of that!

 

[Snarls]

I'm preparing to do the lead screw upgrade for the Z axis. What model X carriage pieces did you guys print to accommodate the lead screws? I see a few different options. Would the official prusa models work?

 

[jhitesma]

I'm preparing to do the lead screw upgrade for the Z axis. What model X carriage pieces did you guys print to accommodate the lead screws? I see a few different options. Would the official prusa models work?

I'm not 100% sure but I THINK the official ones would work as I'm 99% sure that the spacing between the smooth rod and the leadscrew is the same on the FT as on the official from what I've heard.

That said this is the set I used:
https://www.thingiverse.com/thing:936464

They don't look like it at first on thingiverse because he used the end cap of the X tensioner as the thumbnail for some reason...but the parts are in there.

I just pulled both parts up in onshape and measured them...but doing so noticed there's a bit of a difference:

They've both 17mm between centers but the hole sizes are slightly different:

Version I'm using:


Official Prusa part:


I'm guessing the leadscrew nut that Prusa uses is thicker - but I don't have a real Prusa to compare...maybe David (djk4linux) can chime in since he has multiple FT machines and an official Prusa Mk2.

The prusa part also has cutouts to hold nuts on the screws that mount the leadscrew nuts while the parts I'm using you just thread them into the plastic (which I'm not big on so I put nylocs on the bottom.)

The Prusa part though also has slightly smaller openings for the LMU bearings...and no way to clamp them...The lack of clamping doesn't bother me as I've never installed screws/nuts on mine - but I do use the clamping protrusion to leverage them open to fit the bearings in...could still do that on the prusa parts but there's less material to leverage against and it's a tighter fit so may be tricky (but has me thinking about modifying my v groove parts since I was already considering ditching ditching those flanges.

(Ignore the other attached files, I uploaded the wrong screen shots at first but can't find a way to delete them.)

 

[dkj4linux]

I hope this helps...

I am completely happy with the prints I'm getting from my stock FT machine and have not considered upgrading it (especially since getting the Prusa) so really can't address all the upgrade options you mention. For reference, here's the stock M5 threaded rod X-axis ends on the FT...





And here's the Prusa... except for the obvious leadscrew difference, the parts look quite similar...









I'm pretty sure that the printed Prusa parts are ABS... that may account for the smaller LMU bearing "tube" dimensions?

-- David

 

[jhitesma]

Thanks David. Kind of hard to see up the bottom of the leadscrew nut but it does look like the OD of the nut is bigger on the Prusa nut than on the ones you commonly find for sale which are 10mm OD. But the Prusa ones seem to fill that 15mm opening completely. I wonder are those thicker leadscrews...they look like they might be but hard to tell, probably the same 8mm screws.

I printed my upgrade parts on my folger in ABS since I was thinking about doing an enclosure at the time...(and most of my parts since have been PETG since it's easier to print and would also hold up to the temps.) But I think the tighter fit on the bearings is since Prusa relies entirely on the friction fit while the Folger upgradeparts have the screws to make it clamp on the bearings. I wonder what the ID is on the original Folger parts....I know the STL's are out there somewhere but don't have them handy to check. I haven't had the stock parts on in so long I had forgotten they didn't have the clamps either. I wonder if Folger uses the original Prusa X parts from before Prusa switched to lead screws...

 

[Snarls]

Thanks guys I will start printing the parts and hopefully the lead screws will be here sometime this week.

 

[jhitesma]

Found the original Folger STL's:



So they're 15.28...same as the modified parts and still slightly larger than the prusa.

And just for good measure I also checked the original prusa i3 design from 3 years ago:


Interesting...that wasn't quite 17mm center to center (but close) and the bearing hole was only 15mm so even tighter than the others.

BTW if anyone wants to play with these here's the Onshape doc where I did these measurements:
https://cad.onshape.com/documents/6...5d7f91971a574f74ee/e/780c8a3a83c5592f67490d6b

I also did a quick screen recording of how I use onshape for this...but won't be able to edit it and upload it until this evening. Basically I just import the STL, then in the part studio that gets created from the import I do a new sketch on the top plane, I go normal to the plane and then activate the "Use Project/Convert" tool. The Use tool will then let you pick points off the STL, so I pick three roughly evenly distributed points around the openings...if you're not normal to the plane this can be confusing since you'll see the points on the part as well as on the plane and unless the face of the part you're taking the points from is even with the plane you'll see two sets of points. Once I've got the points from the STL selected I use the 3 point circle to re-create the circles. Then I draw a construction line between their centers - though now that I think about it this isn't really necessary...you could just use the dimension tool to get the distance between the two centers...since I then use the dimension tool to get the radius of the circles that would be quicker.

This is also how I recreate parts in Onshape from existing STL's or take measurements from parts to base my own designs off of. Except when doing that I pick a lot more points and recreate the outlines then add features like extrudes to them.

Once you do it once or twice it's really quick and easy.

 

[Snarls]

So the lead screws actually came in today happily enough. I'm printing an enclosure for my RAMPs board first then I will need to go to the hardware store to get some nuts and bolts to install the upgrade pieces. I have the lead screw X axis peices, some Z standoffs to raise the Z stepper motors up, and a four bearing X carriage, but I am not sure about using that. I also have some LED lighting I want to put near the printer.

 

[jhitesma]

So my new anti-backlash leadscrew nuts showed up sooner than expected

Unfortunately they don't fit the parts I printed

The OD on them is slightly thicker than on my original nuts - looks like they need the bigger holes like the Prusa parts have. So...guess I'm going to have to revise my design yet again and go for something more like Prusa's new style X carriage...but with the v-rail attachment.

 

[Snarls]

That's no fun especially when you've waited for the package to show up. Maybe an excuse to make that X axis v rail upgrade sooner?

Today I am installing the lead screws on my machine along with the Z standoffs and some wiring cleanup.

 

[jhitesma]

Well, that's why I haven't installed the X axis upgrade yet Didn't want to take it all apart only to find out that the dimensions for the leadscrew nuts were wrong - then have to put it back together how it was, reprint, and do it all over again.

I kind of had a suspicion that the new nuts were going to have a bigger OD...but the seller didn't have dimensions so I wasn't sure.

Didn't take very long to draw something up though based on the latest prusa parts:



I think I want to redo the right side so it incorporates the stepper mount like the original and prusa parts do though...might also redo the left side so it includes the tensioner....if I'm redoing this may as well really redo it

Oh, and I didn't put the cut in the bearing section yet...gotta do that before I try printing it.

 

[Snarls]

Looks like a good start. As usual redoing one thing starts a chain reaction of redoing.

I'm experiencing that phenomenon right now. What started as a seemingly simple lead screw and Z standoff upgrade is now taking multiple hours. After taking the X carriage off I decided to take another go at the Y axis to make sure it is solid and lined up as best is possible for the smoothest and quietest operation. I also removed the wiring from the RAMPS so I can install a RAMPS enclosure and after doing that decided to remove the RAMPS and Arduino entirely and bring it to my computer to update the Marlin on it. I haven't updated the firmware since getting the printer working a year and a half ago, and now I'm kind of lost in the Marlin settings .

Short story this upgrade is taking longer than I thought but I'm not complaining. Here is what the printer looked like today. Excuse the squareness. I took a vertical photo and don't know how to rotate it so I just cropped it.

 

[jhitesma]

Have you seen the new Marlin config tool?

https://github.com/akaJes/marlin-config

It requires node (though there's a standalone windows version now I think) but once it's up and going it gives a nice visual browser based way to do your configuration...and even better you can just drop your config file from your old version onto the window and it will automatically update to a newer version with the same settings showing you what needs to be changed.