# 3D Printer Build



## bmac2 (Feb 3, 2019)

So I decided to start a build thread on this thing and perhaps share my pain. I needed a new project and started work on it just after Christmas. I’d been reading a lot on the internet, and watching a *lot* of videos on 3D printing but after watching Thomas Sanladerer series “Dolly: The Prusa i3 MK2 clone”. I had to admit I‘d been bitten, I’m still not sure that I have a _practical_ use for one and I certainly don’t think I _need_ one but now I wanted one and I wanted to build it. Tom built Dolly using cable ties and Oriented Strand Board. I thought I should be able to do at least as well just by using something like Baltic Birch plywood. I know it could work out cheaper to just buy a kit but where’s the fun in that? I don’t buy ready-made engines.

I’ve been concentrating on posts where people had either built their own or mods to improve printers and basically stealing everything I thought looked like a good idea.

One recurring problems was rigidity so I’m going with all metal. No wood and sorry Tom cable ties are for tying cable and putting up my wife’s pea fences in the garden. I have a couple of concerns about the potential weight of the X axis but I’m willing to sacrifice print speed for rigidity. As my ideas _slowly_ solidified I started ordering the parts and after Christmas had enough to start getting things tougher.

I used 2020 and 2040 V-slot channel for the basic frame. I had some V-slot and linear bearings left over from my laser engraver. That project could have done with some better planning.

With the corner brackets and T nuts I knew I could have a solid, square frame in no time. After bolting up the frame I marked out and drilled the end plates for the X axis and mounted the Z bearings. I was going to just center punch for the holes (Thoughts of Thomas Sanladerer’s oriented strand board and a hand drill) but chickened out and spot drilled them using the DROs on the mill with the two plates sandwiched tougher then drilled out the 3 and 4mm holes on the drill press.











I’d left the extrusions at their stock length (400 and 500mm) my plan at this point was just have a platform I could build on and cut them down to size later.


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## bmac2 (Feb 3, 2019)

The bottom mount for the Z guide rods does double duty as a 90 degree bracket for the 2040.





I squared up two pieces of 1 in. thick bar stock and trimmed them to 40 x 40mm. I don’t have a lot of metric tooling but between fraction, number and letter drills I can get pretty close and for this project I did order 3, 5, 6 and 8mm reamers for when it has to be right.











I then milled the step and drilled and counter sunk the holes for the 5mm button head screws.


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## bmac2 (Feb 3, 2019)

I have a couple of 8mm lead screws I was going to use on my engraver (bad idea . . . don’t ask) and made the drive nut holders out of .375 aluminum. The only material I had at hand is this stuff that for whatever reason has a rounded edge but it worked.

Cut off two pieces and cleaned them up bringing them down to size then drilled them to fit the drive nut.
















They could almost be used as is but I wanted to round them off and trim them up a bit. After all if I don’t throw in a bit of style this thing is going to look _very_ industrial.

Super lazy setup for the 3”rotary table just toss it in the vise. I used my Arduino controller and once I got the angle dialed in it was just “A” forward, “B” reverse, “Z” down and repeat.





















After finishing them I found I still had to take a small bite out of the end to clear the bearings






And this is why if you build an Arduino Controled Ratary Table you put it into a tight case.


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## bmac2 (Feb 3, 2019)

It was at this point I saw a Myfordboy video on his printer build where he isn’t using flexible couplers (around the 7 minute mark). I guess if you build it straight you don’t need them, so another idea got pinched.


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## bmac2 (Feb 3, 2019)

The more I looked at the frame the more I dreaded the idea of cutting it down. I had some 5mm threaded rod that’s long enough and straight so I thought I’d give the Myfordboy idea a try.

Started with some .375 aluminum and drilled and reamed it 5mm and parted them off.






After dialing in the rod I used the tale stock to slide the coupler on with some JB Weld and left it overnight to set.






I took a skim cut just to clean them up then marked them for the setscrews.






I decided to drill and tap the hole thru so that if I want I can use two setscrews.














I cut a couple of lengths of aluminum angle for the top guides for the Z axis and after indicating in the mill drilled and reamed the holes for the 8mm rods and a small bearing for the screw.
















That about brings this thing up to date. Next up I’m starting on the X axis.


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## vederstein (Feb 3, 2019)

This project must be for the fun of making the printer.  You are definitely going to spend more money on making one than buying one.


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## lohring (Feb 3, 2019)

I own a Preusa Mk3.  Your printer will be a lot more accurate and rigid than it is.  That should give better print quality and the ability to run faster.  It will take a lot of experimenting to achieve that, though.  Good luck.

Lohring Miller


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## XD351 (Feb 3, 2019)

One thing to remember with 3D printers is to keep anything that moves at speed ( print bed and extruder ) as light as possible as inertia can cause a real problem , usually shows up as “artefacts” on the printed part .


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## bmac2 (Feb 3, 2019)

Vederstein

A lot of what I’m using is stuff I already have on hand, Adriano’s, stepper motors/drivers, misc. aluminum. Nothing goes into the garbage (printers?) around here, and maybe the odd time at work without getting stripped of anything I find interesting.  The Anet 8 goes for around $250.00 Canadian with shipping and from everything I’ve read can be a _very_ good printer so long as you don’t try to push it past its limits. But like most of the low cost / affordable to the hobbyist / printers it uses a lot of acrylic and can suffer from issues with flexibility and vibration if you try to push it.

Looking at my spreadsheet on this thing I’m around the $150.00 mark so far. Now I have no illusions that I won’t want to upgrade some of these parts in the future, they are mostly the cheapest I could find but I’ll deal with that as I have to.

*Amazon*

LETOUR Power Supply 12V Power Supply 30A 360W    $31.99

50pc  20 Series European Aluminum M5 T Nut                $4.03

Smart LCD Screen 2004 Display Controller for RAMPS 1.4 3D   $12.76

SODIAL(R) 3D Printer Controller for RAMPS 1.4 Reprap  $6.57

Hotend All Metal V6 Extruder   $8.86

*Banggood*

4) - LM8LUU 8mm Long Linear Bearing     $ 8.16

2) -  Nema 17 42mm 12V Hybrid      $29.08

12/24V MK2B Heated Bed Platform for 3D Printer   $15.70

 Left/Right Side Aluminum MK10 Direct Extruder    $10.95

*Alliexpress*

2) - 400mm Length 2020 T-Slot Aluminum Profile, 1) - 2040 T-Slot   $15.76

power switch  $2.24

TOTAL       $146.10

 Before anyone asks _YES_ I have checked RAMPS board and the foil pattern and MOSFETs are fine.

Lohring

“Will take a lot of experimenting”

That’s why I opted for a RAMPS board running Marlin. With the amount of information available on the internet I think I have a much better chance of getting it up and running with this platform. I did try to contact “Technical Support” on this build for some reason they have my phone number and e-mail address for the help line. I guess I’m on my own . . . except for you guys.

XD351

Yep it should be ridged enough but like I mentioned before I do have some concerns with the weight of the X axis that’s one of the reasons I’m going with a Bowden style extruder.

As I start getting the materials piled up on the bench to start working on the X axis I can see that it’s going to have some weight to it. That said though I think with a ridged frame if I can get everything lined up straight and balanced it should (?) be able to perform as well as many of the commercially available kits on the market.

If nothing else if I can get it running and it craps the bed at some point I will be able to fix it.


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## lohring (Feb 4, 2019)

With 3D printers of the usual sizes the part is light compared to the extruder assembly.  My favorite design so far moves the extruder assembly in the X and Y direction and the part in the Z direction.  Z moves are small and infrequent so all the rigidity needs to stiffen the X and Y axes.  Ball screws rather than belts can help with accuracy as well.  See https://www.projectr3d.com/#overview for a design like I described.  E3D is working on a tool changing, multiple extruder design that's similar.  By the way, Bowden extruders can have issues with flexible filaments.   I have had some initial problems even with a direct drive extruder before updating the Prusa extruder assembly.

Lohring Miller


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## XD351 (Feb 4, 2019)

I think the reason most printers are designed the way they are ( bed does the y axis and extruder moves in the x & z axis ) is that it makes them easier to design and manufacture . This also seems to follow suit for cheap cnc engravers etc but if you look at a cnc mill the head only moves in the z axis and everything else is done by the bed . This keeps everything that moves at any sort of speed down low where vibration ,   any flexing  and inertia can be controlled . I like ball screws and you can also add encoders to them to monitor missed steps etc and they don’t break halfway through a print ! Anyone ever seen a machine that can be switched from 3D printing to small cnc engraver to a small laser cutter all rolled onto one unit ?  Might be a future project !


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## bmac2 (Feb 4, 2019)

Not much progress on the printer. The weather has been just ugly with lots of snow and daytime highs on the wrong side of -30c the past couple of days.

I did get the Z motor mounts finished. I’m using aluminum angle for the mount and milling off the shaded areas in blue.






The only angle I have is 1 ½” (38.1 mm) and a NEMA 17 is 42.3 mm so I had to add a bit to get the width I wanted. I cut a couple of strips from the same material and then brazed them on to one leg.











They got a little ugly on the inside and warped a bit but a light pass on the mill cleaned them up nicely and brought everything back to square.






Then just drilled / bored them to fit the steppers and milled them to shape.


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## bmac2 (Feb 8, 2019)

So this is the plan. Belt tension will be set with the two screws on the right. I started by cutting and truing up 5 pieces of .75 x .5” aluminum bar stock.










Indicated and spot drilled them in the mill for the 3mm holes that will be used to attach them to the end plates then drilled and taped them in the drill press. I love my tap arm.
















Then back to the mill to drill and ream the 8mm holes for the rods using the DRO.


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## bmac2 (Feb 8, 2019)

With that done I spot the holes for the X carriage and finished it up on the drill press.






To assembly the X axis I started by screwing the five 8mm rod holders (I’m honestly not sure what to call them) to the end plates then loosely attached the bearings to the X carriage.






Then slid on the right and left plates. Amazingly everything lined up. Most of the shop time today was spent tuning the bearings. The only way to get the carriage to slide smoothly was to slowly tighten each of 12 screws one at a time. When I made my engraver I was surprised how much tightening just one of the screws just a touch would make.











Dropped it down over the Z rods to get things spaced out and as an assembly I definitely has some weight to it in the Z direction but the X isn’t bad at all.















By shining a light up from below and using a set of feeler gauges it looks good on the left but I’m going to need a 10 thou shim on the right side.









The more I look at it the less I like the belt tensioner. Using two screws to jack the idler out against the rods just doesn’t look/feel right . . . . might have to come up with a plan “B”.
Stripped it down so I could mill down the left end plate to match the stepper and clean up all the dirt, ink and scratches and it was time for a family photo before final assembly.


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## Cogsy (Feb 8, 2019)

On my Anet A8, if you try and put a proper amount of tension on the X axis belt, the guide rods and ball screws flex and just don't allow it (both 8mm which I think you're also using). I'm not aware of a fix for this so I'll be eagerly watching what you come up with! 

Also, just an FYI, the IGUS DRYLIN bearings are supposed to be a huge improvement over the LM8's, both in performance and noise. They're reasonably cheap and a drop-in replacement but I haven't gotten around to ordering a set yet.


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## bmac2 (Feb 9, 2019)

Hi Al thanks for checking in. How are you holding up down under? From what I see on the news it’s either 40c or raining at biblical proportions. Any time your weather makes my news 15,000km away it can’t be too good.

Belt tension looks like one of those things that are all over the map. Some say it should sound like a base guitar string yet I recently read in a Thingomatic manual “If the belt makes an audible noise when you 'pluck' it with your fingers, it is too tight”. Might just have to go with trial and error.



Cogsy said:


> Also, just an FYI, the IGUS DRYLIN bearings are supposed to be a huge improvement over the LM8's, both in performance and noise. They're reasonably cheap and a drop-in replacement but I haven't gotten around to ordering a set yet.



 Everything I’ve read on DRYLIN bearings say that they can make an amazing difference over the ball races. One caution I’d offer before ordering any is to check the reviews. From what I’ve read many of the ones being offered on line are 16mm OD.


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## Cogsy (Feb 9, 2019)

Hi Bmac, where I am is about the only part of the country experiencing mild, pleasant weather. This summer we've had a few 40+ degree C days but not as many as normal, and mostly we're seeing mid 30's which is very pleasant compared to most years. The weird weather systems going on are actually holding off the extremes we normally see - I'm definitely not complaining.

I can only offer my own anecdotal belt tension experience, I haven't got it guitar string tight, but when I added a tensioner to the Y axis and adjusted it quite tight I got much better consistency in that direction. When I tried the same tension in the X the rods just flexed and caused issues.

I just had a thought (dangerous, I know). At least on my A8, if the ball screws were outboard of the guide rods instead of inboard, I could run another rod horizontally perfectly inline between the upright rods, with another set of bearings of course, as a form of bracing to prevent them coming together. Too much work for me though and my prints are reasonable enough for what I need.


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## bmac2 (Feb 10, 2019)

I decided to work on something simple while I ponder how to handle the X axis belt tensioner. The mount for the hot end is very reminiscent of a small split bearing so easy peasy. Squared up a piece of .25 bar stock to 1” by 1” and step drilled to 15/32” then reamed it 12mm.










Drilled two through holes #40 (0.0980 close enough to 2.5mm) then split it along the centre line. All it needs is an oil hole and it would be right at home on this forum.










I ran into a bit of a snag at this point. The idea was to tap the bottom part through as I’m using 3mm screws to mount the block to the carriage as well as the clamp and my tap wasn’t long enough. It was only about 1 – 1.5mm that the tap couldn’t reach so I cut a small notch in the end of a stainless steel 3mm screw and ran it in. It actually worked pretty good and the clamp feels very secure.


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## bmac2 (Feb 13, 2019)

I started on the Y axis motor mount/belt tensioner. Now that it's done I think I might have “over engineered” it a bit but I like it and it is solid.






I started by cutting all the pieces to size and cleaning all the edges.  The base consists of the bottom, two .125” spacers, .125” top and a .25” x .25” piece across the back. These where sandwiched up and clamped together then drilled and tapped for 3mm button head screws.  Screwed up it forms a “T” slot for the motor mount to slide in.






Surprisingly my aluminum angle is still too short for the NEMA 17 so again I just extended it. The wind-chill was barking around -40c so instead of going out to the garage and brazing it I thought I’d just use JB Weld and a couple of stainless pins. If it doesn’t survive machining I’ll just bite the cold and braze one up.


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## bmac2 (Feb 13, 2019)

Left it to cure overnight and this morning I realized that the rounded inside corner wouldn’t allow the stepper to fit flush with the inside of the angle. I set it up in the mill and just kissed it to bring it to square. This also trued up the bit I’d added to the top and the JB Weld held so I guess it will work.










Indicated it in the mill and then drilled and countersunk the screw holes and bored it out for the stepper.
















Once I had it trimmed up I dialed it in on the mill with the sliding plate clamped down. I didn’t want this to move out of alignment so I drilled, countersunk and tapped the four holes without changing the setup.






This was the tricky bit. I slid the motor mount into the “T” slot in the base assuring it was tight against the back and clamped it down. Then carefully marked it so the drill would hit the center between the motor mount and the slide plate.






Opened up the hole in the base to clearance size and tapped the motor mount. The stepper wouldn’t clear the button head screws so I had to counter sink the top on one side.





The screw gives me a whisker over 3/8” travel and the 5mm button head in the front of the mount locks it into place. Over all I pretty happy with the way it turned out . . . . to bad it will be hidden in the back.


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## Peter Randerson (Feb 14, 2019)

Bob
I am following this with interest as I have built my own Cartesian style printer  using 20/20  extrusions and am now onto my second build of a Core XY style machine, again using 20/20 V slot.

Not sure if you are aware but one of the many problem areas on these things is poor eccentricity on the stepper pulleys.  Biggest offenders are the cheap items out of China.  

Genuine Gates belts and pulleys are the best option.  You can read about them here:
https://e3d-online.com/blog/2018/11/29/gates-belts-pulleys-and-idlers-now-available/

Cheers
Peter


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## bmac2 (Feb 18, 2019)

Peter I have to agree with you. Ordering the cheap stuff from China (like everything in this build) can be a crapshoot. I’ve had good luck with most of the stuff I’ve gotten but a couple of items have been absolute garbage. I don’t know if it’s a lack of quality control or someone passing off factory seconds and rejects. I’ve never had a problem getting a refund or replacement but with one month lead times it’s a pain.


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## bmac2 (Feb 18, 2019)

So I finally came up with an idea for the X belt tensioner by mounting it on the back on the X carriage.







 I dug out a cut off piece of the 3/8” flat bar with the rounded edge I used for the Z nut holders. Cleaned up a couple of other bits from the scrap bin for its base and the belt clamp.






Brought the rounded piece down to size then mill an 1/8” slot in it and spot milled a shallow hole in the flat end.











Chucked up some .625 brass in the lathe, drilled it clearance size for #4-40 and parted off a thin washer using the good old bamboo meat skewer to catch it.











Milled the base to shape, drilled and tapped the holes for the jack screw, the guide screw, and the two 3mm screws that will attach it to the carriage plate.






After I got it assembled I clamped it into place to check the fit and  . . . . . it was not going to work. I don’t have enough space between the bearing blocks for the belts.




The solution that I came up with was to mount it on the other side of the plate and to capture the belt on the lower end. This meant having to mill a small bite out of the lower bearing mount to allow the tensioner to move its fell travel but I can’t see it having any effect on the bearings. I may have gotten a little overzealous with my “small bite” but again I can get just over 3/8 of an inch of travel out of it.

The way it works is the bit with the rounded end slides on the 4-40 screw when the jack screw is tightened. It can’t rotate on the screw because the jack screw sits in that shallow hole in the end. When the tension is set tightening the 4-40 screw with the washer locks everything in place.


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## XD351 (Feb 18, 2019)

bmac2 said:


> So I finally came up with an idea for the X belt tensioner by mounting it on the back on the X carriage.
> 
> View attachment 107517
> 
> ...


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## XD351 (Feb 18, 2019)

You could also try ptparts for 2.5 pitch pulleys .
https://www.ptparts.com.au/products...ming-pulleys/12-T2.5-6--t2-5-6-timing-pulleys
These pulleys are only centre drilled each side so you can fit them to what shaft size you like by boring the hole yourself .

I had to adjust the amount of steps on my x&y axis as i was printing 0.5 mm undersize over 25 mm ( half of that is probably shrinkage ) So i set up a dial gauge on each axis and used the controller to jog 0.1 , 1 and 10 mm and noticed some inconsistencies , not huge ones but if i jog 1 mm then another and so on one will read spot on the next over by 0.1 mm and the next under by the same then is will go back to being spot on with the next jog so i would say the pulley isn’t the best . Strange thing is if i do the same using a 10mm jog it is more consistent usually within 0.025 or so .


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## bmac2 (Feb 18, 2019)

The loose end of the belt will just clamp down on the top of the bearing block with the hardly noticeable little notch I milled into it.

I started by trimming a piece of 1/8 inch flat bar to size and setting it up in the mill to cut the slots.






The closest cutter I have to match the belt teeth is 1/32, not perfect but it will work. Set the speed on the mill to “15 year old on his second Red Bull” and slowly cut out the slots. 
With slow feeds and lots of WD40 I got them done without hearing that nasty “_Tink_” sound that small end mills make when they snap.















As luck would have it a good old 3/8” end mill worked out to be the perfect width for cutting the hole for the idler pulley.






With everything back together I was able to tension the belt to the point that I started to worry about the 5mm shaft on the stepper and could see no appreciable deflection on the 8mm rods using a dial indicator.


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## bmac2 (Feb 20, 2019)

I spent the past couple of days making the Y axis carriage (the _Frog_). In retrospect I can’t think of why I made it to match the Prusa I3 when It would have been much simpler to just bore some big holes in it like Myfordboy did to reduce the weight but done is done.

The only aluminum plate I have is .375, .25 and .1875 so 3/16” it will be. The carriage is too big to layout with the DRO on the mill and I can’t see where anything other than the holes for the bearings is all that critical so I just printed it out full size and taped it to the plate. 





If you’ve never used an optical centre punch they’re pretty cool. I don’t use it as much as I did before I installed the DRO’s on the mill but for something like this it’s perfect.





The base has an “O ring on the bottom that keeps it from sliding around and the optical rod has a magnifier polished into the top and a “Cross” in the bottom.






Once you have the cross on the layout mark you hold the base, slide the optical rod out and replace it with the punch and give it a light tap. The optics are much better than in the picture, I guess the camera just couldn’t’ decide where to focus but you can’t get much closer than that.











Once I had it marked out I took off the paper, gave it a once over with an automatic centre punch and marked them for the appropriate hole size then drilled it out.


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## bmac2 (Feb 20, 2019)

I hate having to use sketchy setups. Whenever I mill on a piece of wood it just never feels like it’s clamped down as tight as it should be. But after many setup changes and a bit of cleanup and deburring it was done. Somehow I got the one hole way off centre but I’m just using it to anchor the wiring for the heated bed so it’s ok.


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## bmac2 (Feb 20, 2019)

I got the bearings mounted and sitting on the bench the carriage slides smoothly without the rods wobbling around.








This is where I once again my plan to cut the frame down came back to haunt me. Cutting it down would only shorten it by an inch and a half but at this point I think it’s going to be easier to tweak the rod mounts than disassemble the frame, cut it down and get everything lined up again. And I just might _need_ that extra inch and a half someday.


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## bmac2 (Feb 23, 2019)

Originally the mounts for the Y rods where going to basically be an upside down “T”. The new mounts have a bit more style have a rounded top and step back to catch the rod behind the 2020 V slot.





Started on the rod supports by cutting down some 1.25” aluminum bar, squared it up and milled the basic L shape of the mount.














I left a small shelf at the bottom and cleaned it out with a 3/8” round nose bit to help maintain my “style” points.









Brought the height down and milled out the “tombstones” then drilled the 5mm screw holes.









After cutting them apart on the bandsaw and cleaning them up I indicated them in the mill to drilled and reamed the 8mm holes for the rods. The only critical dimension on these it the distance from the center of the hole to the bottom of the mount.





A quick test fit and I’m happy with the way they turned out. The rods feel ridged even without the locking screws. I’ll finish them off by rounding the top and back on the belt sander and drill and tap the ends of the rods for m5 screws.


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## bmac2 (Feb 23, 2019)

For the idler mount I started with a piece of 1x1 bar and milled out the front keeping with my “rounded” theme. Flipped it over and milled a notch in the back for the overhang then milled down the sides and drilled the hole for the axle before milling the slot in the top for the idler. 














Mounted to the V slot it is solid and shouldn’t flex with any load I’ll be able to put on it. Cleaned it up and another part got checked off the list.


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## bmac2 (Feb 24, 2019)

Ok. Most of the mechanical is done on this thing. I only have the "Y" belt clamp and the build plate left but that involves going out to the garage to cut stuff on the bandsaw and it was just too damn cold out there today. 
So instead of doing anything productive I hooked it up to a 2 axis (so no Z) controller I had around and just played with it.
The horrible grinding noise is one of the bearings on the X axis. I swapped it out and it’s much quieter now.


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## ddmckee54 (Feb 25, 2019)

Bob:

What kind of bearings are in the idlers?  They are going get a lot of mileage put on them.

Don


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## bmac2 (Feb 25, 2019)

Hi Don. The pulleys I’m using are an aluminum body with 2 ball bearing races pressed in similar to the Openbuilds drawing below. I’d never really thought about it but ya over time they won’t ever see high RPM’s but they will be racking up the mileage. Luckily even _good _quality ones can be had for $6 or $7.00.


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## bmac2 (Mar 1, 2019)

Well it finally warmed up enough to get out to the garage and cut some metal. The stuff gets damn cold even with gloves on. I’ve found that when its colder out if I don’t let my saw run free for a few minutes to loosen up it likes to throws the blade.
I’m using 7/32” aluminum for the build plate and it was shear cut so I trimmed a bit off each side to relieve any stresses in the metal (see Myfordboy vid).  









I cleaned up the edges and put it on the surface plate to check it. At first I thought it was warped but I discovered I’d managed to scratch a sizable burr on the bottom. After a light cleanup with a file it looks good.









I screwed the build plate solid to the carriage and with a dial indicator in the head mount it doesn’t look terrible. Now I just have to come up with some springs, from what I’ve read the stiffer the better?


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## ddmckee54 (Mar 1, 2019)

Bob:

The stiffer the better - within reason.  You still want the springs to give if your print head crashes on the build plate.  When you're homing the machine and the Z limit fails you don't want bad things to happen.

Don


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## bmac2 (Mar 1, 2019)

ddmckee54 said:


> Bob:
> 
> The stiffer the better - within reason.  You still want the springs to give if your print head crashes on the build plate.  When you're homing the machine and the Z limit fails you don't want bad things to happen.
> 
> Don



Good point. I guess it could go from “bad things” to OMG! OMG! terrible things in a hurry with a glass build plate. We have a couple of shops locally that mostly just have machines and filament but I’m going to make some calls to see what else they have in the way of parts.
I have a decent stash of small/medium springs but this thing is getting to the point where it would be one less variable I’m going to have to deal with.


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## bmac2 (Mar 2, 2019)

For the Y axis belt clamp I started by sandwiching a piece of .125 and .25 together and trued them to size.





Set up in the mill I drilled the 6 holes #19 (close as I can get to m5 tap size) and then milled the square hole through the .125 piece.   





With a little heat I got the two pieces separated and used a transfer punch to mark the location on the Y carriage and spot drilled it.





I milled a shallow recess in the .25 piece to match up with the square cut into the .125 plate. The middle two holes where then tapped m5 and the outer four drilled clearance size. On the .125 plate the outer four are tapped m5 and the middle two are drilled clearance. All of the holes in the carriage are clearance.













Once assembled the two middle holes mount the (.25) top plate to the carriage. The belt runs in the recess in the top plate and comes out through the square hole in the (.125) bottom plate. The other four screws pass through the carriage and top plate and are threaded into the bottom plate to clamp the belt in place.









I think I went a little overboard on what should have been a simple clamp but it works great. Just feed in the belt, pinch the two ends and tighten the screws.


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## bmac2 (Mar 3, 2019)

I woke this morning and while I was enjoying my coffee the weather man on TV was telling me that the wind chill was -40c.

Sounds like a good day to stay inside and start on the electronics.

Over the past few of days I have been reading up on the pros and cons of the various types of end stops. I have the components for the three most common, mechanical (micro switch), optical, and Hall Effect. From what I’ve read Hall Effect can be less susceptible to noise and false triggering, and I like playing with them so Hall Effect it is.

The sensors I have on hand are A3144. There a unipolar (only one pole will trigger it) and nonlatching. I going to use small neodymium magnets for the triggers and I’m thinking I should be able to get good repeatability out of them.





The circuit is pretty simple just the sensor, a resistor, a small LED for debugging (has to have LEDs), and some veroboard.  Back when I use to do a lot of prototyping many of the circuits did nothing visually so we’d add LEDs to a data bus or clock and call them the “Managerial Circuit”. That way when the boss came around he’d have some blinking lights to look at. Amazing how that worked.














These behave like a normally open switch so go high when triggered.










The mounts are pretty simple and just attach to the V slot with m5 screws. I Installed Pronterface and so far it’s been really handy for testing and sending G-code to the controller.










For now the controller is just screwed to a handy sized piece of aluminum on the side of the frame. This thing is going to need some serious “cable management”. I use to hate having to do harnesses but these days with age and a good audio book it shouldn’t be that bad.





I’m running it on a current controlled bench power supply to help keep the magic smoke in. But everything is moving when it’s supposed to move, stopping when it’s supposed to stop, and hot things are going to a set temperature and staying there so it time to start the software configuration in Marlin.  
This could take a while. Like a lot of cheap 3D printers this thing doesn’t come with customer support.


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## ddmckee54 (Mar 4, 2019)

Don't forget about lights for the build plate.  They really help you see what's going on/wrong with the print.

I'm still trying to figure out how to get some decent light at the nozzle without the part cooling fan ducts getting in the way.

Don


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## bmac2 (Mar 4, 2019)

Hi Don

Yep that’s one of the things on my “_Other Stuff To Think About_” list. I was given some LED light strips and there ok but I just can’t think of a way to mount them where they would light up the build plate without just being in the way. They would probably work well for cabinet lighting but not for here.











My wife had some of those solar Ikea garden lights where the charging circuit had packed it in  and like I’ve said before very little goes into the bin without going through the workshop first. On these I’d salvaged the solar panel and the LED's. Those LED’s are _very_ bright to the point of almost hard to look at. There 5mm and six of them only draw 0.04 amps at 12v with a 320 ohm resistor. I’m like yourself trying to figure out a way to get them mounted close to the head without being in the way.  Looking around Thingiverse for cooling fans and other ideas it looks like the head can get pretty crowded.

Fiber Optic light tubes mounted above the head?


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## ddmckee54 (Mar 5, 2019)

Cable management and lights, these pictures show how I dealt with those issues on my printer.

The first picture is what my printer looked like before I did anything more than using cable ties to bundle the wires.  It was at best an organized rat's nest.





The next picture shows the under cabinet 12V LED that I added for some additional light on the build plate.  This light also supports the cable chain to the print head.  I've read complaints about cable chain being too noisy and that you shouldn't use it.  I've found that is you take the time to ensure the chain is moving freely it is virtually silent.  All I get is a slight click as the link sets down on the support, the stepper motors make more noise than the cable chain does.





The  third picture shows what it looks like with the light on, and the light comes on whenever I power up the printer.





The last picture shows what things look like after I got done "Killing the rats" and eliminating their nest.  All of the blue parts and the white parts have been printed by this printer to improve itself.  Some of the stuff, the cable chain in particular, I found on Thingiverse and modified to suit.  The rest of the stuff was my design and a way of learning how to use my 3D CAD package.






Don


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## bmac2 (Mar 6, 2019)

Don thanks for the pics. You have a very nice tight setup. Your LED strips look a lot brighter than the ones I have and I like the cable chain. It seems like there’s little middle ground with cable chain either you love them or hate them.

I’ve got a 3D CAD that I’ve been using for around 10 years and I dreaded the thought of having to learn another system. But a couple of weeks ago I dug out the manual and _actually read_ the chapter on stl files. I was experimenting with exporting some of my existing files to Slic3r and at first couldn’t figure out what was going wrong until it dawned on me that Slic3r assumes that the file dimensions are in mm. Sort of explained why when I imported a part that was 2 inches long and a half inch wide it looked so tiny on the screen.

When I started casting I had to rethink some of the ways I drew things up. Draft angle, wall thickness and could the pattern even be pulled from the sand. Now going through some tutorials on various slicer programs I have to start thinking in terms of “can it be printed?”, “will it need supports?”, “will the supports affect the print?” etc.

Good thing this is a hobby . . . .


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## ddmckee54 (Mar 6, 2019)

Slic3r is good, and the Prusa version of Slic3r is even better.  You sure can't beat the price and I always thought that Slic3r was better at recognizing where supports were needed than Cura was.

Late last year I bit the bullet and bought a copy of Simplify3D.  OMG what a difference.

The biggest differences I noticed is in  perimeter wall and the top layer quality.  I've got a 0.4mm nozzle have always had trouble with Slic3r when printing objects with relatively thin walls, more than 0.4mm and less than 2.0mm thick.  If Slic3r is not able to fit an even number of perimeters between objects, or in the perimeter wall, it leaves a gap.  This isn't good for wall strength and looks like crap on the top layer.  Simplify3D gives you the option of either filling this gap with the infill pattern, or extruding a single filament to fill the gap.  I made the mistake of trying the infill option - once.  You haven't seen a 3D printer in the spastic mode until you watch one trying to infill a gap less than 0.8mm wide on the top layer.

The other big difference is printing with support.  I used to avoid printing with supports like the plague, I ALWAYS used to have trouble removing supports.  To get the supports where I thought they were needed, I had to put up with supports everywhere that Slic3r thought they were needed too.  I used to add a single or a double perimeter sacrificial wall that I would later remove just to avoid printing using supports.  Simplify3D allows you to really control the supports, adding or subtracting them where you need to.  The supports are much easier to remove also.  I've since been able to print complex cavities where I was able to remove all of the supports for that cavity in one piece.

Not an ad for Simplify3D - just my observations,
Don


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## ddmckee54 (Mar 7, 2019)

Small parts, that's another nifty thing about Simplify3D.  If you try printing small parts, and my rubber band gun design has several of them, Simplify3D asks you if you accidently tried feeding it imperial parts instead of metric parts.  Then it offers to convert them for you.

Don


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## bmac2 (Mar 10, 2019)

I got one of those personalized ”_recommendations for you_” e-mails a while back from Amazon that had some PLA cheap ($9.00 for a 1 lb. spool). I knew I was going to need some and probably use most of it just getting this thing calibrated so I clicked on the link, read the reviews, and ordered it. When it arrived I thought I knew why it was on sale . . . . This stuff is _PINK_. And not just pink it’s so pink it almost glows.
I’ve spent a lot of time reading on the internet the last few days and thankfully there is a ton of information on Marlin available.  As usual my biggest problem was figuring out what things are called. I knew what I wanted to change but had no idea what they called it but I felt I’d gotten to where it was ready to print.
The first attempt was a total failure with the nozzle too far from the bed so back to reading about bed levelling and setting nozzle height.





The second attempt was more successful but the layers started shifting. The curious thing about this print was that it didn’t shift consistently. The “o” in Hello is good and the shifting got progressively worse doing to the left.





After another night of reading I decided it was ready to print a 20x20 calibration cube. This is where I learned about infill. If you don’t have any infill there’s nothing to support the top layers. Idiot.





It’s not pretty but as a tool I was happy with it. The Y axis was shifting badly and perhaps being printed too hot the X looked better. Time to read up on 20x20 Calibration Cube print defects.










One thing that came up repeatable was that the belt tension wasn’t tight enough so I tightened the belts . . . . . . . . Ok. Apparently that wasn’t it. . . . . . Back to Google.


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## XD351 (Mar 11, 2019)

Looks like your x axis is jumping steps , could be the amount of current from the driver to the stepper or acceleration/ deceleration settings in marlin , what speed are you printing at ? What is your maximum travel speed set to ? 
What is the x& y jerk settings set at ? Are both axis nice and free to move with no binding ? Are the drive pulleys locked to the shaft ? 
Thomas sanladerer does a good tutorial on marlin settings on youtube .


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## ddmckee54 (Mar 11, 2019)

I would sometimes get same step shift as shown in several of your pictures, not that mess in last one picture though.

I personally think the step shift is a Slic3r glitch.  I could never find the "smoking gun", but I did find that I could re-slice the model, generate a fresh g-code file, and the problem would go away.

That last picture looks like you definitely caused a problem with the Y-axis drive.  When you took out the extra tension that you put in the belt did the problem go back to the single shift in the Y axis that you originally had?

I have had models that have caused a physical shift in an axis like this.  These were usually caused by trying to print too large of an unsupported overhang when printing multiple parts at once.  The thin edge would curl up as it cooled and sometimes this lip would catch the print head as it traveled to print the next layer.  If the curled edge was big enough and hard enough, it would cause the printer to lose steps.  This is not the problem with your cube since you weren't printing any overhangs.

If you haven't tried re-slicing the model yet, just for giggles and grins, give it a try.

Don


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## bmac2 (Mar 11, 2019)

Hi Don. Nope this wasn’t caused by a Slic3r glitch it was a definite Bob glitch.

Bingo XT it was driver current. A lot of this thing is made up of bits and pieces I had around including the stepper motors. I’d pre-set the stepper drivers and in the process of building it and tearing it down I’d paid close attention that the two Z axis steppers where a match but mixed up a couple of the others. At some point the 1.5amp stepper on the Y axis was only been fed .75 amps. Tightening up the belt did not make it very happy. Went back through my stash and did a more selective job of picking the motors so all are now 1.5amp 1.8 degree. The rest of the machine checks out being square and true with no binding so back printing stuff.

I have no idea what _normal_ is for a 3D printer so I’m just using the default settings in Slic3r (perimeters 60mm/s, maximum travel speed 180). Marlin is yet to be tuned so that will be more trial and error but this thing didn’t come with a manual. Calibration is always a slow respective process of documenting changes and repeating the same test over and over (20mm cube) but I’m starting to make some real progress.

The “Print Quality Troubleshooting Guide” at Simplify3d has proved invaluable getting to this point

I’ve was messing around with layer height and temperature settings in Slic3r. I Changed layer height to 0.2mm and printing at 205c with everything else still at the defaults. To me it’s looking pretty good.

Can you get filament with a decongestant? This things nozzle gets like having a three year old with a cold in the room.


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## XD351 (Mar 11, 2019)

Looks good !
The constant dribbling from the nozzle can be because the hot end temp is a little high , try 190c . I usually put my first layer down at 205 c then have my slicer settings back it off to 190 and the top layer is at 175 c . You will find different pla will like different temps but somewhere between 175 and 205 is a good starting point .
My printer died last week - motherboard cooked itself , well the power section for the drivers and micro did anyhow . The micro seems ok ( removed some damaged components then powered it up via a remote supply and the lcd still shows the programme running but there was no power to the drivers . New motherboard ordered and i now have to make a circuit up to test the drivers as I don’t want to fry the new board if one of the drivers has a dead short ! Anyhow that is enough of me hijacking your post !


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## ddmckee54 (Mar 12, 2019)

For the initial prints on a new machine this is looking pretty good.  A lot better than some of the prints you see on videos, some of those are just nasty. 

You'll have to play with the temperatures and print speeds to find the sweet spot for your machine.  Every machine is different, you need to find what works best for yours.  Even different colors of the same brand of filament will perform differently.  I've had white filament from one manufacturer that wanted to print at 230° while black filament from the same outfit wanted to print at 210°.

I've found that my machine is happier printing in the 45-50mm/s range for perimeters, just seems like I get better print quality at a slightly slower speed.  It's a  balancing act, you want a good looking print, but you don't want it to take forever to print the stinkin' thing.

Like XD351 said if it's dribbling it's probably too hot.  I have to run my temperatures in the upper end of the print range, I typically print PLA in the 215-230° range.  At least that's what my printer says the temperature is, I haven't been able to figure out a way to verify the actual temperature with the hardware that I've got.  My IR thermometer doesn't like shiny surfaces.  Every time that I've torn the hot end apart I've been in a hurry to get the printer running again so I've never bothered to paint the hot block with BBQ paint to see if the flat black would give me a better reading.

Extruding hot filament is good, because you get better adhesion between layers.  But hot is also bad because you've got to get the heat out of the layer you've just printed so that you can print additional layers.  If you haven't got a part/filament cooling fan that'll be one of the first things you want to add.  I highly recommend a radial blower type fan as opposed to an axial fan.  The blower will move a lot more air which is what you want.  There are several cooling fan duct designs on Thingiverse, pick one you like and print it out.  I printed mine out of PLA and a long as I keep it at least 1/4" away from the hot block I don't have any problem with it deforming.  I picked up a trick from youtube for fine tuning the cooling fan duct design, use a shallow dish of water on the build plate.  This allows you to lower the nozzle to the surface of the water and actually see the ripples where the cooling air is hitting the surface.

Above all, remember this is SUPPOSED to be fun!

Don


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## Peter Randerson (Mar 12, 2019)

Dialing in an own design 3D printer can be a long and involved process given the number of variables.  However, You Tube has some excellent tutorials and diagnostics available.
It appears to me that you need to do a couple of initial steps:
1.  A PID tune (Google it) of your extruder temp control.  Done in Marlin Firmware.
2. Calibrate your Extruder stepper (Google it) so that when the Gcode asks for 10mm of filament it actually gets 10mm of filament.

I would also recommend subscribing to the following You Tube Channels:
Makers Muse
3D Printing Nerd and
Tom Salanderer


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## XD351 (Mar 12, 2019)

There is also the reprap calculator on the prusa website , this makes calculating the steps per mm or inch of travel easy .


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## bmac2 (Mar 17, 2019)

XT, Don I think I have my post nozzle drip settled. Part of the problem was I’d been poking around with the “end” G-code and inadvertently deleted the M104 command to turn off the nozzle at the end of the print. Also I’d calibrated the extruder but I hadn’t checked the filament and my 1.75mm filament is more like 1.82mm so I was also over extruding. As far as “SUPPOSED to be fun” I love this sort of thing. I’m recently retired and I have a very understanding wife that doesn’t mind if I want to disappear into the shop for a couple of hours, or days, as long as I get my “chores” done.

Peter I am defiantly a graduate of YouTube U. Most of this printer is ideas off YouTube and there was a lot of pink goo between the first cube and that last one.

I’m trying to use up the pink stuff as fast as I can with a tool holder and a bird feeder. The bottoms warped on both but the chickadees don’t seem to mind. By time the feeder was done it was barley holding onto the bed. I guess I should get the bed heater installed.













One thing. Is it normal to have to relevel the bed every half a dozen or so prints? I’ve been reading up on auto bed leveling and I’ve got a few ideas but I think it might be the way to go.


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## XD351 (Mar 17, 2019)

You might need to adjust your retract settings in your slicer , i would put a mark on the z axis feed screws ( i use a sharpie marker ) that way you can confirm that both of the z axis screws are homing in the same spot . My printer never seemed to home correctly after a print so I guess it was losing steps homing the z axis I don’t see why you should have to re level the bed although i check mine every print but rarely have to adjust it ,if you want auto bed levelling you will have to configure it in marlin and hook up a probe to either the servo port if your board has one or z minimum on your machine  i have just fitted the new motherboard and loaded the latest edition of marlin and i had a hell of a time getting the z axis to home properly . It turned out that there was some noise causing it to false trigger which can be configured in the config.h settings . Still thinking about moving the bed heating mosfet off the board as it gets awfully hot ,i made up a simple driver tester. ( polulu or stepstick)  so i can pre configure the current setting and test operation before plugging it into the motherboard and it made life much easier .
Your prints look ok with no stringing so you can’t be far off with your settings .


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## Peter Randerson (Mar 17, 2019)

Bob
For me the heated bed is an essential element (pardon the pun) for keeping prints in place,
You asked about bed leveling. My current printer is a cartesian (same as yours) with a 2020 ally frame.  I am using a Duet wifi controller and a BL Touch Z probe.  With the Duet software I can run a multi-point leveling sequence that provides a mesh that the software can use to adjust level.  I run that sequence before every print.   Even with that I find I am having to manually re-level the bed every couple of weeks.
I have some theories on why the bed goes out of level but no answers on fixes:
1.  I am using 2 stepper motors for the Z axis.  It takes very little to get these out of alignment.  Even 0.1mm is enough to affect the print.
2. The bed is mounted on 4 springs, and is in constant motion when printing.  Ask yourself, is that the best design for maintaining an accurate level surface?
3. I use a brass brush to clear ooze from around the nozzle.  By design, the print head is far from rigid so rubbing a brush over it on a regular basis may knock things out of alignment.
I have read that the bed should be mounted on 3 points rather than 4 to make it easier to attain and maintain level.
My nest printer will be a Core XY  with the bed only moving in the Z axis and using one stepper.


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## bmac2 (Mar 30, 2019)

Just an update on the printer. I think I found the problem I was having with keeping the bed level. I noticed that the loops and brim on the prints where thin to the point of being transparent. Parts where sticking to the bed so hard that I had to use a lot of force to break them free consequently messing up the bed. After many hours of reading, fiddling around with Marlin and running test prints I finally have the nozzle height dialed in correctly. I must have missed that chapter in the setup manual . . . oh yeah no manual. 

I’ve added bed leveling, parts cooling fan, and lights. The bed leveling works pretty well for DIY. It’s loosely based on the BL Touch. In a lot of the advertising they say how the BL Touch they don’t use a servo they use a solenoid to lift and drop an aluminum rod with a magnet on the end that triggers a hall effect sensor.

I remembered that when I bought my first Arduino Kit it came with one of those little 9G servos so mine has a servo lifting the probe. Drew up a simple mount and printed it out. The hall effect sensor is the same as I used for the limit switches I just made it about half the size so it would fit.   











At first I couldn’t get the servo arm to catch the probe reliably and after about an hour fiddling around trying to add a small lip to the arm it dawned on me that I was sitting in front of my laptop (with CAD) beside a working 3D printer (idiot). A half hour later I had it assembled and was working on setting the deployment and retraction angles.









The probe is a 1/16” brass rod with a 1/8” neodymium magnet epoxied to the end. This one works pretty god but I’ve found one on Thingiverse the BFPTouch  (https://www.thingiverse.com/thing:2890290) that uses an optical sensor and is a lot neater being enclosed that I might give a try. I scrapped the one in the picture and redid the mount so the probe was on the inside closer to the hot end.










My parts cooling fan is definitely a version 1.0 but better than nothing for now. The lights are 4 LED’s mounted in the hot end cooling fan and put a lot of light right on the nozzle.

As a test for all the tweaking and tuning I printed another small bird feeder. The wall's only 1.5mm thick and it’s about 170mm tall with no supports. It took about 5 hours to print but looks cool in the white PLA and the chickadees love it . . . . or maybe it’s just free food.


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## Cyril H (Jan 25, 2020)

Very professional looking, wish I had the time left and facilities to do something similar. Well done


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