Creating Prusa(toms Dolly) design using aluminium frame. end stop question

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bentech4u
Posts: 46
Joined: Mon Aug 28, 2017 4:07 pm

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by bentech4u » Mon Oct 09, 2017 7:22 am

HI,

My PLA is on the way and it will reach soon, meanwhile, i got sample ABS from one local store, i cant wait without trying that :)

i have changed the value and printed one 20 mm cube, all the measurements are correct now. But the print has some issues, i cannot able to explain much, and the total cube is a little slant. Please check below and advice me what is wrong.

https://imgur.com/a/GlGEN

Layer height = .2
speed = 35 mm
infill speed = 45 mm
travel speed = 120 mm

Extruder temperature = 230 C (First layer & other layer)
Bed Temperature = 90 C for first layer and 50 C for other layers.

chumm
Posts: 113
Joined: Thu Jun 15, 2017 11:24 am

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by chumm » Mon Oct 09, 2017 7:57 am

The slant may be due to the two Z screws sitting at different heights. You can check this with a ruler, looking at the height of your X smooth rods on the far left and far right. You can manually adjust the height by turning one motor while they are off until they are both sitting perfectly even. Once they are even they should stay that way unless the axis is pressed on and moves (very unlikely with threaded rod, common with lead screw) or you have some motor issue where one of them misses steps.

You also have banding, which is the ribbed effect of the outer layers sticking out at regular intervals. They are probably sticking out at the same interval as your Z threaded rod (1.25mm I think you guys figured out). This is common, because threaded rods are rarely perfectly straight. Are you using a flexible coupler like this?:
Image

If so, you should make sure that the threaded rod and the motor shaft do not touch, they should be inserted on either side of the flexible part with the whole flex area used as a gap, like this:
Image

bentech4u
Posts: 46
Joined: Mon Aug 28, 2017 4:07 pm

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by bentech4u » Tue Oct 10, 2017 6:55 am

HI

thanks all, Almost everything is working now.and now i am getting perfect prints.

bentech4u
Posts: 46
Joined: Mon Aug 28, 2017 4:07 pm

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by bentech4u » Thu Oct 12, 2017 9:35 am

HI

i got my PLA spool and when i tried to extrude, filament is always jamming on hotend. removed, cleaned everythin. again same.

i was using temperature of 200 C and using the extrude button on printrun to extrude.

chumm
Posts: 113
Joined: Thu Jun 15, 2017 11:24 am

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by chumm » Thu Oct 12, 2017 3:14 pm

Did you get any filament to push through? When you change from ABS to PLA, you need to keep the hotend at the ABS temperature at first to push out all the remaining ABS that is sitting in the nozzle. So I'd set the hotend to 230-240 and extrude until you get a decent amount to go through. This is easier if the two filaments are different colors because you can see when the old color has completely run out.

bentech4u
Posts: 46
Joined: Mon Aug 28, 2017 4:07 pm

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by bentech4u » Sat Oct 14, 2017 8:53 pm

HI,

i did the same only, heated up to 240 and cleared all the ABS. and many times i cleaned the nozzle and eating barallel manually by opening it , again the same thing.

my cooling fan on e3d clone is only turning on while i start printing..is that normal behavior?

heat sink on top of heating barallel is too hot, is that making an issue?

anyway please find below pictures of jammed filament

https://s1.postimg.org/12y4fi74fz/20171012_164133.jpg
https://s1.postimg.org/6x6mt4rflr/20171012_164237.jpg
https://s1.postimg.org/4gx5sdmjxr/20171012_171731.jpg
https://s1.postimg.org/2axr6m5tpb/20171012_171750.jpg

chumm
Posts: 113
Joined: Thu Jun 15, 2017 11:24 am

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by chumm » Sun Oct 15, 2017 3:16 am

Yes it definitely seems like your heatsink is too hot. The fan should run full speed the entire time the printer is on. The fan that blows on the heatsink should be connected directly to 12v power, not to the "fan" connector on the board, that connector is for the part cooling fan, if you have one. The part cooling fan has variable speed and is controlled by the software, but the fan on the heatsink should always be going.

Do you have a PTFE tube in your hotend? It should be something like this:
Image
This keeps the filament sliding nicely, offers some slight heat barrier, and holds the filament close so it won't bend when it is being pushed through. If it's too hot this will still fail, but it sounds like the fan connection is the primary problem.

Edit:
Also make sure when you reassemble the hotend that you tighten it while it is hot. This will ensure a better seal than if you tighten it cold. If the seal is bad melted filament will leak and create a mess and a clog.

bentech4u
Posts: 46
Joined: Mon Aug 28, 2017 4:07 pm

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by bentech4u » Sun Oct 15, 2017 7:20 am

Thanks a lot, i have connected the FAN directly to 12 V and the jamming issue solved.

again another 2 issues

1. the first layer is not correct(before for ABS also i had this issue and that got solved by increasing headbed heat)
2. total object is little slanting to Y MIN direction

For the first issues, please find images, Also suggest my layers are correct or not
https://pasteboard.co/GOZOyFd.jpg
https://pasteboard.co/GOZOLpo.jpg
https://pasteboard.co/GOZP52K.jpg
https://pasteboard.co/GOZPg7q.jpg
https://pasteboard.co/GOZPyoq.jpg

For the second issue, i have noticed this for all the prints,

https://pasteboard.co/GOZPMGx.jpg
https://pasteboard.co/GOZPYz5.jpg

chumm
Posts: 113
Joined: Thu Jun 15, 2017 11:24 am

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by chumm » Sun Oct 15, 2017 9:18 am

When you see very thin lines like that with gaps between them on the bottom layer, it means you are printing the first layer too high. The filament is falling a short distance and landing on the bed instead of being pressed into it and creating a solid fill. I am assuming you are leveling the bed with an inductive probe. You can adjust the height of the probe so that it detects Z = 0 slightly lower, but the easier solution is to correct for it in the slicer with a Z offset.

Here's the Z offset in Slic3r, it is located under printer settings.
Image

To figure out the value, you can experiment with different negative numbers in increments of 0.1mm, so -0.1, -0.2, etc., until you get a good looking first layer. This video shows some good examples of how you want the bottom of your print to look (the middle two in the thumbnail are good, yours is more like even higher than the one on the left):


You can also figure out the value by homing your axes, then placing a single sheet of paper under the nozzle. You then move the Z axis down 0.1mm at a time while sliding the paper around until the nozzle just starts to touch the paper. However low you go, that is the value to put int he Z offset field. So if you moved it down 0.4mm before it touched the paper, you set -0.4 in the slicer.

There is a safety setting to prevent you from moving the axes below 0, so you don't crash into your bed or endstops. You may need to disable this by setting the following to false:

Code: Select all

#define min_software_endstops false // If true, axis won't move to coordinates less than HOME_POS.
Fixing this problem might also fix problem number two, because if it is starting the print too high there will be some gap on the bottom of the print, which could collapse and cause the print to lean as more filament is deposited on top. If you fix the bottom layer and still have some slanting, you should check that all axes are square to one another. This can be kind of hard to do with any squaring tools, mostly I just try to use math and measurements instead.

bentech4u
Posts: 46
Joined: Mon Aug 28, 2017 4:07 pm

Re: Creating Prusa(toms Dolly) design using aluminium frame. end stop question

Post by bentech4u » Sun Oct 15, 2017 9:37 am

HI

Thanks, I always used to level with paper as auto bed leveling is not configured. I will try to put closer to the nozzle and will try.
. If you fix the bottom layer and still have some slanting, you should check that all axes are square to one another. This can be kind of hard to do with any squaring tools, mostly I just try to use math and measurements instead.
could you please tell me what is that about and how it's working/calculating?

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