Prusa i3 3D printer

[tekkydave]

I've ordered some heatsinks for my drivers.

I've ordered some of those now too. The supplied ones rely on the thermal paste to keep them attached and I have knocked a couple off already. The self-adhesive ones look a good idea. I have also ordered a spare set of driver modules as they do run hot and are very sensitive to overload. I destroyed one yesterday by turning the trimmer pot past half way. They need to be around 10-20% clockwise from zero on my build otherwise they just overheat. I have a fan supplied in the kit which will be fitted permanently to blow on the board once it is all attached to the frame and tidied up. I think the RAMPS is a good board but the drivers are 'living on the edge' of their design a bit.

[Gina]

Yes, I shall use a fan for cooling which I will include in a printed case for the electronics.  I'm not all that happy though even with a fan as these drivers seem somewhat underspecified.  I think I shall have to look into using something else as I don't like things running near their limit.  I think this will apply particularly to my larger 3D printers but I have had burnout problems with the extruder drive too.

BTW, if you would like any 3D prints done before you get your printer working I shall be happy to print them for you FOC

[tekkydave]

Yes, I shall use a fan for cooling which I will include in a printed case for the electronics. I'm not all that happy though even with a fan as these drivers seem somewhat underspecified. I think I shall have to look into using something else as I don't like things running near their limit. I think this will apply particularly to my larger 3D printers but I have had burnout problems with the extruder drive too.

BTW, if you would like any 3D prints done before you get your printer working I shall be happy to print them for you FOC

Very kind offer, Gina. I'll let you know if I need anything.

[saac]

I need to stop reading this!  My things to buy in 2015 list is already on its 3rd revision and it's only Jan 2nd.  Having seen how Gina's printer has been earning it's keep and now the progress you are making Dave, I can easily see how a 3D printer would come in handy.   So what's the advice, go for the DIY build route or an "out of the box"  model?  Dave, It may be a bit too early to ask this of you but how are you finding the DIY choice, is it what you expected, any particular concerns and would you recommend that route?  What are the advantages/disadvantages of each option?  I can already see a fair bit of research needs to be done before committing to a purchase but I think I'm sold on the idea at least.

Jim

[tekkydave]

I need to stop reading this!  My things to buy in 2015 list is already on its 3rd revision and it's only Jan 2nd.  Having seen how Gina's printer has been earning it's keep and now the progress you are making Dave, I can easily see how a 3D printer would come in handy.   So what's the advice, go for the DIY build route or an "out of the box"  model?  Dave, It may be a bit too early to ask this of you but how are you finding the DIY choice, is it what you expected, any particular concerns and would you recommend that route?  What are the advantages/disadvantages of each option?  I can already see a fair bit of research needs to be done before committing to a purchase but I think I'm sold on the idea at least.

Jim

It depends on what your level of mechanical/electronic knowledge is. The kit I bought is certainly not for beginners. I have had to play around quite a lot so far to get the 3 axes running. There are no instructions supplied and the various guides on the web are often unclear and contradictory. I've had to learn quite a lot in a short time but it is very interesting. If you like a challenge and can manage basic electronics then go for a kit, otherwise if you can afford it get a ready-made model like the UP!

[Gina]

The UP! is not perfect but what is, particularly for a reasonable price but I think it's probably the closest you'll get to "plug n play" in a 3D printer.  Here's an independent review by MAKE magazine.  They also review a number of other 3D printers.

[saac]

The diy route is certainly attractive regarding cost and it could also lend itself to a nice project for use in the classroom.  Gina if I have read that review correctly then the features in the Up such as auto leveling and auto head height sensing are nice features and will no doubt end up as industry standard. The resolution of the printed produced looks good too.  From your use of it to date what other specification highlights would make you recommend it or otherwise?  The quality of the print I think would be my main consideration within budget limits of course.  At the end of the day I think the budget is going to make the decision here.  Isn't this always the problem with emerging technology!  If you're early adopter you make the purchase knowing full well that in a few years the price falls while the product spec generally improves.  Maybe a mid price DIY machine would be good entry point after all.

Jim

[tekkydave]

Had to go to work yesterday (boo) but back on the 3D printer today. I decided to re-do the hotend thermistor as I wasnt happy with my first attempt. I drilled out the hole in the heater block to 3mm and also slightly deeper. This allowed the thermistor to sit deep enough in the hole so the leads didnt short on the block. I rewired it using the spare thermistor supplied in the kit. Im much happier with the 2nd attempt - the thermistor is now secured correctly and cannot be pulled out when the cables are flexed.

I also noticed that the bolts below the heated bed mountings were catching the vertical frame as the Y axis moved backwards. I removed the washer under the nut and also added 5 washers above the spring to reduce the length of bolt projecting below the frame. It now clears the frame by about 5mm.

[Gina]

Gradually getting there Dave

The Arduin Mega came today so I'll be trying the electronics shortly.  I won't be doing anything strenuous with the motors until I get the heatsinks and arrange fan and air cooling though.  Could you tell me which site you downloaded Marlin from please?  When I tried things before I couldn't get the electronics to work and research showed several different versions of Marlin.  I haven't tried Pronterface so could you give me that link too please, so that I know I'm using the same software as you (that works).  I used Repetier Host with the Velleman and whatever it had installed as firmware in it's own version of the Mega.  Thanks

[tekkydave]

Marlin is on github at https://github.com/ErikZalm/Marlin/releases/tag/1.0.1

I downloaded Pronterface from http://koti.kapsi.fi/~kliment/printrun/

Use the Printrun-Win-Slic3r-10Mar2014.zip link for the latest windows release.

There are links to Linux & Mac versions on the Reprap wiki page http://reprap.org/wiki/Printrun

One thing I read is that to compile the Marlin code you need the Arduino V0023 ide not the latest version. You can get this from the Arduino website.

[Gina]

Thank you very much Dave

[tekkydave]

With everything all connected up and tested I decidec to try a print. I noticed the 30mm fan on the E3D extruder wasn't running. When I checked it with my multimeter and it was open-circuit. I don't know if it ever worked as this was the first time I checked it. I have ordered a replacement. In the meantime it seemed to be ok without it - when I heated the hot-end to 185 there was very little heat in the heatsink. So I levelled the printer, levelled the bed and checked the x-axis was level. I chose a z-axis endstop holder to print. I inserted the 3mm PLA into the extruder and checked it was extruding ok using manual extrude button in Pronterface. A nice blob of molten PLA appeared on the nozzle so I pressed print. It printed part of the outline then no more PLA was extruded. I couldn't get any more to go through or pull it back so I assume there is a blockage somewhere. I'll have to take it apart and clean it all out. Trouble is it seems to have heated up the extruder a bit so I cant remove the heatsink now. I might have to heat it up again to get it out. I should have waited for another fan but it didn't seem to be getting warm at all.

[Gina]

Yes, it's usual to have to heat up the hot end to get it apart.  Blockages tend be be a problem with PLA

[tekkydave]

Yes, it's usual to have to heat up the hot end to get it apart.  Blockages tend be be a problem with PLA

I think my first print when I get it going is a new extruder. I have ordered some spare e3d v6 parts just in case.

[tekkydave]

I have managed to do my first prints. I decided the first thing I would print should be something useful and fairly small. I printed a z-axis endstop bracket for the Prusa i3 kit. That went well so I decided to print a 20mm calibration cube. That also printed ok. The x and y axes are exactly 20mm but the z is only 19.3mm. I think I have the bed a tad too high and the first layer is getting compressed. It wasn't extruding much plastic until it moved onto the 2nd or 3rd layer.

[Gina]

Have you set up your Z axis zero point Dave?  That is the only thing I can think of if the first few layers aren't extruding much.  If that is set correctly it will compensate for a high print bed.  A high print bed will reduce the Z range you can get though.  HTH

[tekkydave]

Have you set up your Z axis zero point Dave?  That is the only thing I can think of if the first few layers aren't extruding much.  If that is set correctly it will compensate for a high print bed.  A high print bed will reduce the Z range you can get though.  HTH

I think it is setup ok. When I home the z axis I can just get a piece of folded paper to slide under the nozzle. I am going to try lowering the bed a tad and see if it makes a difference.

[Gina]

Sounds about right

[tekkydave]

I have raised the z-axis zero point and it's behaving a lot better now. I am currently printing some filament spool brackets. I'll post a pic later, each bracket is estimated to take 1hr 38mins.

[tekkydave]

The right-hand bracket has finished printing. This is based on an item I downloaded from Thingiverse. I widened the 'mouth' of the bracket from 7 to 22.5mm using Sketchup to fit over the edge of the cabinet above the printer. They could potentially support multiple spools by placing a section of dowel between the brackets.

[Gina]

Looking good Dave

[SnakeyJ]

Have to agree - that bracket looks nice and solid and has a good finish.

[tekkydave]

Looking good Dave

Thanks. The left-hand bracket wasn't 100% perfect. When I lifted it off the bed some of the layers started to separate. It's still useable with a bit of glueing I think

[Gina]

Maybe a slightly higher hot end temperature might cure the adhesion problem.

If it's ABS, acetone works well for gluing parts together.  Doesn't work with PLA.

[tekkydave]

Maybe a slightly higher hot end temperature might cure the adhesion problem.

If it's ABS, acetone works well for gluing parts together.  Doesn't work with PLA.

I'm using 3mm PLA. Temperature is 200C. I'll try a bit higher, maybe 210.