thereprapkitstore.com Prusa Mendel construction Notes/Discussions

What temperature are you using? the one in my config file? I'd also have a go with some force air cooling after the first layer. Send me your stl file and I'll have a go at printing it.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

Yes, your temperature from the config file.

Attached is the STL file.

Cheers,

Keukpa

STL File

Edited 1 time(s). Last edit at 06/24/2012 12:45PM by keukpa.

This is printing now. I can see where some of the problems are though but I'm no expert. RepRap struggles with circular overhangs. I'd try and remodel using octagonal extrusions rather than circular ones. It can build overhangs but they have to be 45 degrees or less to the bed.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

Ah right! Hmmm, I look forward to seeing your print to compare.

I'm going to try and print a cog from teh Prusa stock and see if that turns out OK!

Keukpa

Here Goes...

Before fettling...

Recogniseable but a bit rough
The bridging worked well and the little eyelet on the back is perfect

After fettling...
I've filed and scraped and applied some modeling filler
And the other side

I thing we have the same problem though. Our machines really struggle with small parts. I was getting a lot of blobbing on the left hand mounting bracket and on the end of the middle wall. Hopefully, nophead or RichRap can tell us what's going wrong in this and my thin wall calibration.

I've just noticed something though. My part is a mirror image of yours. It's mirrored in the X axis. Have you got your motors running the right way. Come to that, have I? I've just loaded the model into MeshLab and it looks the same as mine so I think yours is the wrong way.

keukpa Wrote:
-------------------------------------------------------
> Ah right! Hmmm, I look forward to seeing your
> print to compare.
>
> I'm going to try and print a cog from teh Prusa
> stock and see if that turns out OK!
>
> Keukpa

Edited 1 time(s). Last edit at 06/24/2012 02:36PM by MotoBarsteward.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

the back of yours looks better than mine however!

I was just printing, and was looking well and my heat resister burnt out!!

Anyone know where I can get a replacement? In the UK?

Thanks,

Keukpa

I'm wondering if your thermister calibration is correct. The PLA looks very glossy which would indicate to me that you were extruding at a much higher temperature that you think. This might explain your resistor failing. If you look for the BOM for the J Head, it gives the details there. Maplin might be a good start, other wise RS and Farnell take private customers.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I've got a high temperature thermometer, so I'll put that against the head and test.

Luckily my resistor is fine, just the wire (in the shrink wrap) came loose, so I'll fix it tomorrow and try printing a cog

Cheers for all the advice.

Keukpa

I'm getting pretty fed up with every print failing now. The lack of guidance from James is a real problem, I've completely lost interest in my printer already and am verging towards selling it on. I don't really have a use for anything I'm printing and Thingiverse is full of outdated and badly modelled objects with little to no instructions on print settings. If I can manage to get decent prints I may try and reimburse some of the money invested in it by printing some parts but other than that I don't have much use for it.

I think the temp tables are wrong in the firmware James is using but I haven't checked this.

I can almost smell your frustration! Where in the country are you? Maybe find and go to a local user group meeting. Just talking through problems face to face really helps. I never got or expected any assistance from James. I expected all of my support to be 'cloud sourced' and, other than what I've worked out myself, that has been the case.

When I bought my kit, I was worried that I would be eternally disappointed. The first things I printed were parts for my Prusa and they came out really well so my expectation went up hugely. I am now trying to print more complex parts and the machine is struggling. As you point out, much of the stuff on thingiverse is rubbish and has obviously never been printed by the designer.

What have I drawn from this?
1. Check the bed height and level before printing each day.
2. My Prusa really struggles with small things unless I use active cooling. Even then, it struggles because material deposition takes time to stabilise on each layer. Small parts don't have long paths so the percentage of the part with unstable deposition is higher hence poor quality.
3. The RepRap parts are designed to be printed which is why they tend to print well. I only print parts from thingiverse that have photos of printed parts.
4. It might take 2 or 3 attempts to print something. Watch the first layer go down and be prepared to start again if it's no good.
5. This is a machine that I built myself in my garage for £435 that is attempting to do what commercial machines for 20 times that price do. When my machine has a good day on a well designed part, it is as good as any commercial machine. On a bad day, I through a lot of stuff away, believe me. But, all the time I'm learning. I am now at the point where I think I can design my own parts.
6. To be honest, the default params worked pretty well for. Changing them just screws things up because I don't know what I'm doing.

Keep you chin up and try to meet up with the sages sometime like nophead or richrap (sorry if I've missed anyone out who's helped me). Remember, most people build these machines for the challenge and they certainly provide lots of that. Keep your chin up. Take a break for a couple of weeks and go back to it. Learn to drive the machine by printing easy parts like parts of its self.

remondo Wrote:
-------------------------------------------------------
> I'm getting pretty fed up with every print failing
> now. The lack of guidance from James is a real
> problem, I've completely lost interest in my
> printer already and am verging towards selling it
> on. I don't really have a use for anything I'm
> printing and Thingiverse is full of outdated and
> badly modelled objects with little to no
> instructions on print settings. If I can manage to
> get decent prints I may try and reimburse some of
> the money invested in it by printing some parts
> but other than that I don't have much use for it.
>
> I think the temp tables are wrong in the firmware
> James is using but I haven't checked this.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

You're right I did buy the machine for the challenge initially but I didn't anticipate it being so maintenance heavy once it was setup. I'll stick with it a little longer but I can't see it getting much use in the long run. Any ideas what a fully built machine goes for? I looked on ebay but couldn't find any completed listings for a fully built machine.

The part about James was regarding the build instructions- if it's not built correctly from the start then any advice I'm given at a later stage is irrelevant if it's not built properly. I am getting prints out of it but the main issue is excess plastic oozing out despite a variety of retraction settings, particularly at the end of a layer, which deposits on the printed object and ruins a perfectly good print. I don't have time for a 2 hour print to fail 3/4 of the way through and have to restart it not knowing if the next one will do the same, all the while I'm sat there babysitting it.

remondo, I'm printing your part again but at 175 degrees. I can see something interesting. The extruder appears to be not match retract with force feeds. I would expect the extruder to extract at the end of a pass, Z up and move to the new place and Z down. I would then expect it to fast extrude what it retracted and to start printing again. It appears to be doing fast extrudes without retracts at the end of the previous part which is why we get blobs on your two pivots. It should also start each new layer at a randon place and its not doing that. I am wondering if there is something wrong with the slic3r.

I'll slice with an older version and see what happens.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

It is probably trying to move the extruder with too much acceleration and stalling it when reversing.

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[www.hydraraptor.blogspot.com]

You might be right. I also thing I'm extruding too much material as well. I've increased the filament size slightly to see if it improves things. I remember you saying something once about the extrude rate being too high. Can you remember where you said it and point me there to save you repeating yourself.

nophead Wrote:
-------------------------------------------------------
> It is probably trying to move the extruder with
> too much acceleration and stalling it when
> reversing.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I think I might have over tightened my hobbed bolt when I put my extruder back together the other day. I'ts making a squeaking noise on the retract and return that it was making before.

I will try adjusting it. If that makes no difference, I'll quarter the extruder acceleration in Configuration.h and quarter the retract speed.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I don't remember what I said but I have the extrusion multiplier set to 0.85 in Slicer and 1 in Skeinforge for the same machine.

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[www.hydraraptor.blogspot.com]

Almost completed printing with the slowed down and decelerated extrude axis. If anything, I think the part is not quite as good! Watching very closely, when it is doing the first half a dozen layers, there are a couple of times where it moves from one island without retracting and to the other island and de-retracts, i.e. squirts out too much material.

nophead, can you adjudicate here please? Are these challenging parts for the machines that we are dealing with? I think so. It would be nice to see what you can do. It only takes 30 minutes to print and the STL file is earlier in this thread. As can be seen from the attached photo, all the adjustments that I have made have not really had any effect. The part on the right is one that I have 'fettled', filed and done a tiny bit of filling. The parts are usable with a little care.

Picture 1
Picture 2
Picture 3

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

hey, go look at the Slic3r web page. They've released a new version, 0.8.4, to fix, wait for it, blobbing when you start a new layer!

i'M NOT GOING MAD!!!!!

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

Ahhh new version of Slic3r? Awesome! I'll be trying that.

Well, I've been having a good play today, and y prints are getting much better! I've reprinted the Cam Holder seen above, and although not perfect, it is much better.

Cam Holder

I'm getting more pleased with this printer, the last problem I need to solve and I'll be a happy chappy is the warping a seem to be getting on larger parts, this lart is 12cms in diameter, and the edges have curled, even with a brim.

Edge curling

I'm thinking about blowing warm air across the part as it prints to help reducing cooling, what do people think?

Cheers all,

Keukpa

Well, that's a whole couple of days wasted because of a bug in slic3r 0.8.3. The attached image is what I've just printed using 0.8.4. No fettling at all required. I'll send this one to you as well, keukpa!

Machine all back to it's former glory!

Interia dimensions still not right though. The perimeter calibration piece still wont fit.

Beautiful
Beautifuller
Even beautiful on it's back!

Now to change my signature!

I wish I new what these bits were for.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

WOW! That is certainly beautiful! I'm going to upgrade ASAP!

Could you also attach your configuration file MotoBarsteward? That will help me ensure I'm printing with the same settings I'm certainly excited about this now!



Cheers,

Keukpa

It's just occurred to me. Are you printing in ABS or PLA? I'm using PLA.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I noticed there was a slic3r update and gave that a go along with the 2mm retraction (I was using 1-1.5 previously). I printed a belt tensioner which came out pretty well, I'll have to give some of my other prints another go with this update.

MotoBarsteward that print is very nice, congrats!

As Nophead recommended previously in this post, you may want to try the Marlin Firmware, it's said to improve curves.

Edited 1 time(s). Last edit at 06/25/2012 06:28PM by remondo.

Quote
MotoBarsteward
It's just occurred to me. Are you printing in ABS or PLA? I'm using PLA.

I'm printing with PLA. The stuff from faberdashery. Came with the printer.

Any chance on getting your settings file so I can try and recreate your excellent prints?

Cheers,

Keukpa

Yes, the 0.8.3 slic3r set me back a bit. I am planning to try the Marlin firmware soon. I've bought the bits for the display module that it can control

Skeiforge looks like I need to give it ago. I'm having trouble getting internal and external dimensions right. Internal ones are about 0.25 mm too small and external ones are about 0.25mm too big. The perimeter test parts won't fit despite being beautifully printed.

My filament measures 2.84 mm in diameter but I've tried putting 3.00 mm into slic3r and it made no difference. Anyone got any ideas what's going on and how to fix it?
remondo Wrote:
-------------------------------------------------------
> I noticed there was a slic3r update and gave that
> a go along with the 2mm retraction (I was using
> 1-1.5 previously). I printed a belt tensioner
> which came out pretty well, I'll have to give some
> of my other prints another go with this update.
>
> MotoBarsteward that print is very nice, congrats!
>
> As Nophead recommended previously in this post,
> you may want to try the Marlin Firmware, it's said
> to improve curves.

Edited 2 time(s). Last edit at 06/26/2012 02:39AM by MotoBarsteward.

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

WOW! With this new version of Slic3r my prints are sooo much better.

Still not perfect....need to get my settings right, but certainly much better!

Keukpa

Started a new thread for my part size problem: -Hole, inside and outside dimensions wrong

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

I still can't get mine to look as good as yours! I think my settings are out!

What size nozzle and layer height are you settings?

Keukpa

0.4mm nozzle, 0.3mm layer height

keukpa Wrote:
-------------------------------------------------------
> I still can't get mine to look as good as yours! I
> think my settings are out!
>
> What size nozzle and layer height are you
> settings?
>
> Keukpa

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Using ABSPrusa Mendel Zaphod with Pronterface and slic3r 1.3.0. Printing well with 3mm PLA and ABS through 2 x J Head Mk IV b and Wade Geared Exruders. Controlled using RAMPS1.4 board running Marlin_v1.1.9

OK, I think I've got it now! (Thanks for the settings and help MotoBarsteward)

I'm now very happy with my printer >< I think my prints are looking really good! Check these out:

Before bug fixes - This was BEFORE new version of slic3r.

New nice print
New nice print 2
Nice new print 3

I was having problems with this particular print lifting from the bed, but with the new 'brim' setting in slic3r this is no longer an issue!

No warping

I'm very happy now! All looking good.

MotoBarsteward - I have a challenge for you....I can't for the life of me get the following item to print, other printers have done it, but on this one it just fails.Up for a challenge? I've attached the STL file below.

STL Challenge

Cheers,

Keukpa