RC Tank Warfare community hobby forum

Just had a really annoying failure on the printer. Under the heated bed is a block into which the drive belt which moves the bed is fastened. this is accomplished by pulling the belt taut and sliding it into the teethed groove under the block. Unfortunately the block has warped in the heat and now no longer grips the toothed belt. Anyway I have bodged it temporarily by inserting a thin strip of styrene so the belt now grips the block and will work until the replacement part I have requested from the supplier arrives. Very irritating failure but fortunately fixable. The very annoying thing was that I was one and a half hours into a two and a half hour print job!!!

Alwyn

PS I have just realised I have contributed to my own downfall by allowing the CURA program to default print in the exact centre of the heated bed which is exactly where the block which has warped is located. moral of the story - don't print in the centre of the bed every time.

I'm glad to hear you got it sorted Alwyn! Out of curiosity, did they handle the replacement process well? I've heard different experiences with different manufacturers and have seen this with other products like drones where one OEM has spare parts and forums out the wazoo, and others are a ghost town and no response voicemail boxes.

I've just sent the e-mail off so I'll let you know how quickly they respond. They have a depot in Derby which is just down the road, so I'm hoping for a rapid response. Fingers very definitely crossed!! I've also put some baking foil under the heated bed and above the block which warped to try and stop some of the heat getting to the failed part.

Alwyn

Alwyn, there is always a problem with plastic parts, heated beds and 3D printers. The common cure is a sheet of cardboard wrapped in the wide aluminium tape that you can get from B&Q, just stick it under the heated bed between the bed and anything that can be damaged by heat.

http://www.instructables.com/id/Insulat ... eated-Bed/

It's why I haven't hooked up the heated bed on the one that I have just built, I have three motors, three belts and three plastic corner joints all in close proximity, along with all of the wiring. Mind you, until I can get a Buildtak sheet on there, plus preferably a flat glass bed, I can't print anything properly. The heated bed is concave, and I can't print PLA on it as it won't stick.

Thanks for the tips Rob, I made a cardboard shield and covered it in kitchen foil. I tried putting it immediately beneath the hot bed but it really didn't like that, so put it below the springs distancing it from the hot bed. It worked a treat. Also did a bit of maintenance as the x-axis belt was looking a bit floppy and tightened that.

End result is the best prints I've had since I started. I think it's a combination of overdue maintenance, the new printer cabinet which is keeping the printing at a constant temperature, and fixing the y-axis problem

I suddenly realised it's Chinese New Year so no reply from the supplier about the failed part. Hopefully they will get back to me when they sober up!

Alwyn

If you look on Thingiverse, and seeing that this is likely a common fault, you might find that someone has designed a (better) replacement part that you can print yourself?

Thanks Rob, yes I found a similar block on thingiverse, it's just lacking a place to fasten the end stop sensor. I was a bit stumped at first as they only had the .stl files but I checked and openscad will allow import of stl files, so I'll get cracking on that today. It means I have to strip the y platform to get the exact dimensions of the old block, then modify the new design, then reassemble the y platform to print the new part, then strip again to fit the new part............
The joys of 3d Printing!
At least it means I'm not dependent on the supplier, and demonstrates the beauty of the reprap philosophy of open source design.
Alwyn

I tried the STL import thing in Openscad. It doesn't give you an editable file, it simply imports the whole thing with one command. What I had to do was use it as a template to build the part that I wanted around it, eg holes in the correct place and correct diameter. Then comment out the import code so that i was left with the part that I designed. In this example I imported two of the printer parts, aligned them, and then designed a new part that was one piece.

Printer part 1: Printer part 2 New part above: New part underneath: Printed new part: The way to do it is :

//module antiwobble()
//{
//import("/home/rob/Desktop/Smartrap Parts/RELEASE/antiwobble_support 8mm.stl");
//}
//
//module base()
//{
//import("/home/rob/Desktop/Smartrap Parts/RELEASE/plate_base.stl");
//}

module topsteady()
{
$fn=100;
difference()
{
union()
{
translate([-45,-66,17])cylinder(14,14,14);//bearing outer case
translate([-59,-80,17])cube([100,50,10]);//base plate
translate([-26,-80,23])cube([67,35,15]);//tools

}
translate([28,-37.5,4])cylinder(20,4.1,4.1);//rod hole
translate([-45,-37.5,4])cylinder(20,4.1,4.1);//rod hole
translate([-45,-66,0])cylinder(50,6,6);//thread hole
translate([-45,-66,19])cylinder(14.1,12,12);//bearing inner
translate([-24.5,-78,24])cube([63,31,15]);//tools
translate([-30,-77,52])rotate([-30,0,0])cube([75,37,15]);//tools slope sides
translate([28,-26,22])rotate([90,0,0])cylinder(10,1.5,1.5);//clamp screw hole;
translate([-45,-26,22])rotate([90,0,0])cylinder(10,1.5,1.5);//clamp screw hole;
translate([-9,-62.5,20])rotate([0,0,0])cylinder(20,16,16);//pritt stick
}
}

topsteady();

Thanks Rob that really helped a lot, I've managed to import a Y axis block and add my bits to it for the end stop micro switch. Just have to check and adjust dimensions now.

Alwyn

All was going so well until the Demon Murphy struck.

The auto-levelling suddenly went nuts and the print head made it's way towards the ceiling.

After much bad language, checking, rechecking, scratching head, tearing hair, and numerous texts to Wibblywobbly who helped enormously and kept me sane, I diagnosed the bed proximity sensor as faulty and constantly registering as being near the bed. There followed a frantic search for a replacement and for once Amazon came up trumps so I am waiting for the new part whilst champing at the bit. I did contact the supplier but being Chinese New Year I am still waiting for a response as they are in Shanghai.

Anyway onwards and upwards.
Alwyn