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Nicolinux

3DR Delta Bot (continued)

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Posted · 3DR Delta Bot (continued)

There are many RepRap shops selling "M8 hobbed bolts for Wade's Extruder Drive". I never bought one of these myself (I'm designing my own extruder drive using MK8 drive wheels), but I suppose these are what you're looking for.

 

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Posted · 3DR Delta Bot (continued)

I've decided to go with simplicity. This one was on Thingiverse. It's perfect as long as it works.

2014 11 25 23.06.56

2014 11 25 23.07.13

 

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Posted · 3DR Delta Bot (continued)

Cool, I guess it uses an MK8 right? Wanted to print it too but decided to go with the stock one. Not too fond about the filament change mechanism.

 

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Posted · 3DR Delta Bot (continued)

Well, the Ramps mount I designed didn't work because the Ramps sits way to low with the LCD cables attached, which directly effects the moving parts. I had to sacrifice the spool holder and mount the Ramps on top. I figured it's probably time to design a spool holder with bearings that mounts on the side of the printer, which is fed directly into the extruder. It doesn't look as nice as the original design, but I really like having the electronics accessible. I was ready to finish the build this weekend, but I forgot to order some 4mm threaded T-slot nuts for the pulley system at the top.

I'm really surprised at how sturdy this printer is once it's together.

Here are some pics of my progress:

2014 11 28 12.36.18

2014 11 28 15.05.32

2014 11 28 15.05.54

2014 11 28 15.37.17

2014 11 28 16.15.44

2014 11 28 16.47.18

 

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Posted · 3DR Delta Bot (continued)

This is how the modified iRobert's Spool Holder came out. I just love his design. I used 608 bearings with a custom mounting bracket for the extrusion and I used 1/4" all-thread with a custom spacer.

iRobert

iRobert

iRobert

iRobert

 

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Posted · 3DR Delta Bot (continued)

If all goes as planned, the rest of my parts will arrive this week and I can attempt to get it working. I think I spent more time modifying this printer to my liking than the original build took. I just hope everything works as planned.

Here are some more pics of the way I mounted the spool holder & Extruder motor. I had to design a custom mount for the motor to sit in the position I wanted and at the right distance from the extrusion. The filament will go right from the spool to the extruder with about 4-6 inches in between.

Extruder, Mounts, & Low Friction Spool Holder

Extruder, Mounts, & Low Friction Spool Holder 2

Extruder, Mounts, & Low Friction Spool Holder 3

Motor & Spool Mounts

Motor & Spool Mounts 2

 

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Posted · 3DR Delta Bot (continued)

Well, I'm still waiting on some t-slot nuts to complete this build.

The hotend mount I worked so hard on will not work because of the rods hitting the fan, so I had to design another one, which works the same as the one found on thingiverse, except mine is secured different.

Oh, and I used 3mm locking nuts instead so it never loosens up.

Efector & Mount

Efector & Mount3

Efector & Mount2

Effector and Hotend Mount

2014 12 04 22.29.43

2014 12 04 22.29.52

2014 12 04 22.30.04

 

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Posted · 3DR Delta Bot (continued)

Too bad it didn't work because I would have saved quite a lot of build height.

Btw. do you have a good idea about a fan for the printed objects that does not take too much space around the micro platform and ideally blows air on both sides of the printed object? So far I have only found fan holders that are either too big or where I wouldn't believe that the air could still be squeezed through.

 

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Posted · 3DR Delta Bot (continued)

I have a great idea which allows up to 3 fans mounted around the effector. Not quite sure about the fan sizes yet, but they can mount to the existing screws that hold the rods to the effector. I'll add a pic here when I get a chance.

 

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Posted · 3DR Delta Bot (continued)

Nice one Nicolinux!

Still no progress on my side for now. Too much work...

I hope I'll get somewhere over the holidays.

 

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Posted · 3DR Delta Bot (continued)

That print came out beautiful! I am still waiting on 3 t-slot nuts to finish my build, lol. I had to order them from Misumi and they took a week just to ship em out. I think they come in today.

How many prints did it take to get that great resolution?

 

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Posted · 3DR Delta Bot (continued)

It took 2-3 weeks but in the end I could have had it from day one (after the build was finished)... There is a tuning workflow for delta printers that ensures the nozzle maintains its height when it travels above the bed. I started with this workflow but I could never get it to the point where it was stable. So I fiddled quite a lot with the settings - most notably DELTA_SMOOTH_ROD_OFFSET. I even built a z-probe and added it to the head hoping that it would compensate for any build errors I was having. Because it looked like a build error (skewed assembly, bad plastic parts or something like that) was the only possible answer.

 

When I tried to print, the first layer would never stick and just catch on to the nozzle. I never tried to print directly after I turned the printer on. I always did move the head/nozzle via gcode just to test movement. But as soon as I tried to print right after turning it on - it was perfect... WTF?!

There is one key component though. I ditched the LM6UU linear bearings and bought Igus bushings:

 

The printer is much quiter and the movement of the arms is very smooth now. They're not cheap though.

 

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Posted · 3DR Delta Bot (continued)

That's how it looks now (the three caps at the top are missing because I needed to increase the tension on the spectra line).

3DR Now

 

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Posted · 3DR Delta Bot (continued)

About the bearings:

You have to be careful when selecting the right bearing / bushing.

First, there's always good and bad quality parts. Second, a good bearing / bushing comes with a recommendation for what shaft tolerance to use.

For example, the igus bushing I was looking at (didn't find the part number you specified..) says to use "h6 or h7" shafts.

I use Misumi LMU8 linear ball bearings which are recommended for "g6" shaft tolerance. And I bought g6 shafts (of course).

So you need to match the bushings to the shafts in order to get good results.

iirc, the difference between g6 and h6 is that g6 is specified as "nominal diameter is maximum", whereas h6 is specified as "nominal diameter is minimum".

The Ultimaker linear bearings rattle like crazy on my g6 Misumi shafts - but they run smoother on the Ulitmaker shafts. While the Misumi bearings almost "crunch" on the Ultimaker shafts, but run smoothly on the Misumi shafts.

 

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Posted · 3DR Delta Bot (continued)

Looks awesome and the print result, too. Good work. Hope I will finish mine soon. But not this year anymore... Never ending story.

 

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Posted · 3DR Delta Bot (continued)

Thanks guys.

@Jonny: Well I didn't think too much about the Igus bushings. Maybe I was lucky because they fit perfectly. The smooth rods rattle a bit but they did that before with the cheap LM6UU's too.

The build plate is from here:

 

The hbp doesn't fit so I created an adapter that uses the holes that are already present in the 3DR base:

 

 

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Posted · 3DR Delta Bot (continued)

Hi all,

my 3DR is about to be finished soon. Unfortunately I broke my Merlin Hotend and while I had to wait for a new one I decided to give it a go with a pencil ;)

 

 

 

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Posted · 3DR Delta Bot (continued)

video speed is at 400% I forgot to mention :oops:

but I think it would be possible to print with 4x times the speed in reality too.

IIRC travlling was S500 and drawing S1000 - why? because I made a mistake while editing the gcode ;)

 

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Posted · 3DR Delta Bot (continued)

Onkel,

What electronics are you using in your build? I'm having a very difficult time getting mine to work with the Ramps 1.4.

 

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