Dibloff's Build Log

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Re: Dibloff's Build Log

Postby dibloff » Fri Nov 02, 2012 1:48 am

Mike

When I designed the belt clamps I made sure they'll maintain the belt location as the original belt clamps. The idler I've got is what is in the parts list.

Thanks

A.
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Re: Dibloff's Build Log

Postby dibloff » Fri Nov 02, 2012 1:52 am

Taraaaaaaaaaaaam!!! The QU-BD extruder arrived today!!! It was in a nice small box. Everything was packaged well, meant to survive the USPS roller coaster ride.
I think my package received a special touch
2012_1101_QU_BD_001.jpg

Here is what was in the package:
2012_1101_QU_BD 004.JPG
Last edited by dibloff on Fri Nov 02, 2012 12:59 pm, edited 1 time in total.
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Re: Dibloff's Build Log

Postby dibloff » Fri Nov 02, 2012 2:16 am

I got down to assemble the extruder. Nathan put the assembly instructions videos here: http://www.youtube.com/watch?v=84sZuvFrwmg&feature=plcp
Everything is pretty straightforward, and I hope you can too tailor the insulator to wrap around the hot end without a flat pattern showing the cutout locations.
I’ve ran into three issues dirung the assembly:
1. The threaded section on the small screw that holds the thermistor is too long (4.55 mm). If you drive the little screw in until hard stop there will be a gap of ~1.35 mm. Since the thermistor legs with the insulation are only 0.75 mm the screw will not clamp the thermistor leads down. I ended up using a shorter screw.
2012_1101_QU_BD 005.JPG

2. The filament block is not symmetric. See my drawing below. If you put it together in the wrong way it’ll hit the stepper motor register and the mounting bolt holes will not line up. Make sure the thinner section of the block (3,95 mm) is towards the motor shaft
2012_1101_QU_BD 023.JPG

3. Finally. The heater element does not fit into the hole on the hot end. The heater element diameter is 5.55-5.57 mm while the hole diameter is 5.28-5.30. I can grind down the heater element case or drill up the hole. I have not decided yet which one I’m going to do, but I’m not going to force it in with a press just yet...
Still debating with myself how I’m going to mount the extruder on the bracket. I want to make sure it is solidly mounted on the bracket.
2012_1101_QU_BD 024.JPG

Otherwise I'm impressed with the design. It is simple and looks professional. Hope it'll run nicely.
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Re: Dibloff's Build Log

Postby chelseat » Fri Nov 02, 2012 4:49 am

Ummm I don't know where the lipstick came from!!!

Try a little more hand torque on the small socket cap screw that holds on the thermistor. We have assembled over 900 extruders at this point and we haven't had one yet that couldn't go in all the way, although some of them required a little more ooomph!

Sorry about the hole for the power resistor. We use a 5.3mm drill bit to enlarge the milled 5mm hole that is for the heater cartridge version. Obviously there is some variation in the diameter of the power resistors...it looks like you got an extra big one. I suppose its better to be a bit tight than too loose.

E-mail me at chelseat@qu-bd.com and I can send you a coupon code for our store for your trouble!

Chelsea - QU-BD
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Re: Dibloff's Build Log

Postby dibloff » Sat Nov 03, 2012 3:02 am

Here is the build log for Friday night. I decided to mount the extruder directly on the bracket, without additional plates, brackets etc. The majority of the mass is the stepper motor, so I need to make sure I constrain it to the bracket properly, otherwise during high accelerations it’ll live its own life and will wobble around.
So I did the unthinkable. Those Chinese designers who put the casting marks inside the bracket will curse my name. I removed the non-drive end bracket from the stepper and recreated it in 3D. Later I tried to find a place for two M4 holes that will not intrude into the mounting holes, and the screws will still have 3-4 threads engaged. Since the M4 pitch is 0.8 this meant 2.4-3.2 mm wall thickness. It was tough but I managed to design it properly. The holes are 9.4 mm from the edge. Here is a drawing.
ArcSoft_Image8.jpg

And here is a view of the holes on the bracket. I drilled and tapped the holes, and I’m using two 8 mm long M4 screws. 3.2 mm of that is the hadron bracket thickness, the rest goes inside the motor bracket. I made sure the screws will not touch the insulator or field coils inside the motor.
2012_1102_Hadron 002.JPG

I also added a hole to the filament block. This way I’m going to have three bolts mounting the extruder, and a three legged table will never wobble, right? I have to file off the corner of the filament block, this was necessary because the bracket has a larger bend radius than the 3D model. I believe they had issues with the thicker aluminum plate when they bent it.
2012_1102_Hadron 006.JPG

Finally here is how the extruder looks on the bracket. Notice my fortune cookie message for today: Learn Chinese: Electricity, Dian...
2012_1102_Hadron 004.JPG


Chelsea. No problem. I like challenges, and I overcame all of them as you can see. I drilled out the holes tonight for the heater element and it slid in without any issues. I appreciate your offer, but I'm going to kindly decline it.
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Re: Dibloff's Build Log

Postby orcinus » Sat Nov 03, 2012 1:35 pm

The way you've mounted the extruder seems like a nice way to eliminate low frequency oscillations due to high accelerations, but might make it prone to vibration.

You've fixed one end of it and left the other "hanging" freely. Depending on the mass distribution on the left side of the extruder and the stiffness of the long bolts, that might turn out to be a problem or not. Might be a good idea to stuff some double sided foam pads under the "free" end nevertheless, though.
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Re: Dibloff's Build Log

Postby dibloff » Sat Nov 03, 2012 2:44 pm

Hi Orcinus. Thank you for your comments. I was thinking about the same thing what you've outlined, but if I experience any additional vibrations there I can use a longer screw (out of 4 mounting the fan) and a small angle bracket to tie the free end of the fan to the hadron bracket.
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Re: Dibloff's Build Log

Postby orcinus » Sat Nov 03, 2012 3:12 pm

Sounds good. The reason i'm mentioning vibration is because that seems to be my next obstacle in pursuit of better prints.
I'm getting some rather noticeable "shadows" around high frequency detail on the Y axis and less noticeable but still present "shadowing" along X.

Also, sometimes, some rather funky interference patterns that i think are caused by Z axis vibration combined with either X or Y.
I got a few prints with (regular) diagonal banding on the sides. Pretty weird effect.

My next steps are probably to try and dampen all the steppers with silicone padding and then to find a way to dampen the print bed vibrations without giving up the springs (without them, i think i'd have had 4-5 broken hotends by now).
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Re: Dibloff's Build Log

Postby dibloff » Sun Nov 04, 2012 9:34 pm

Not sure why have I decided to go with the plug in connectors on the Azteeg X3 board, but I think the main reason was that it looks more professional, and the connections are more repeatable once it was done properly.
I did all the crimping over the weekend. I managed to borrow an AMP crimping tool, and after I screwed up one terminal it did all the rest beautifully. I’m sure everyone in this community was born with the knowledge how the crimping needs to be done, how to pair the wire with the terminal, and how to orient the terminal in the tool etc. I wasn’t, but I think I managed to do it properly.
Here is the finished crimped terminal. I did not solder the wire before crimping, just twisted it and cut to size. This is the finished terminal:
2012_1104_Hadron 003.JPG

Here is the AMP tool (left) and the one I bought @ Fry’s (right). Notice the amp tool has different size jaw for the bare wire section and for the insulated wire section.
crimping_tools.jpg
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Re: Dibloff's Build Log

Postby dibloff » Sun Nov 04, 2012 9:44 pm

I crimped the wires for the Z axis stepper motor together in parallel – just as the controller’s drawing specifies. When you do that with a stepper motor - magic happens. I can never get enough of this. If you turn one of the motors shafts (slow or fast) the other one will turn in synchrony. You do not need to have to power the motor for this. It is happening because the motor’s rotor is magnetized and when it rotates it’ll generate EMF, this will travel thru the vires to the other motor and make that rotor turn. It’s kind of real magic. I think this will work for all three phase asynchronous motors too.
2012_1104_Hadron 004.JPG
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