MakerFarm 8" i3v Prusa build by Printbus

[printbus]

Hi Printbus, I totally forgot about your comment about needing the ball driver, I will pick one of those up tonight. do you think having 4 springs is better than 3 and a spacer? As to the end stops, I put them where Colin said to without really looking at the board itself. could my less than stellar sodering jobs be related?

If you have the endstop connectors where Colin shows them, and the mins work OK, maybe the right answer is to not worry about the maxs. The configuration.h file has the #defines for the pullups on the input pins for the max endstops commented out; this likely prevents the internal pullup being activated for those pins on the MEGA2560 processor. That would lead to the input being randomly read in as high or low depending on how the unconnected pin tends to float. With the #defines for the max inputs commented out, firmware likely doesn't do anything with the inputs for the max switches. Your soldering is likely fine, since the min and max endstop switches would be on separate connectors on the RAMPS board.

I prefer the four springs approach. It allows me to just get the Z endstop anywhere close, and then all fine adjustments are done in the four corners of the bed. Of course, I have thumbwheels on the corners now too. Leveling the bed takes me about two or three minutes. The stock makerfarm approach can easily take 20-30 minutes because of the crude approach for mounting the Z endstop switch, the complexity caused by the fixed corner that requires a near-impossible fine adjustment of the Z endstop, and the multitude of tools required to adjust the other corners.

[usarmyaircav]

If you have the endstop connectors where Colin shows them, and the mins work OK, maybe the right answer is to not worry about the maxs. configuration.h as the #defines for the pullups on the input pins for the max endstops commented out; this likely prevents the internal pullup being activated for those pins on the MEGA2560 processor. That would lead to the input being randomly read in as high or low. With the #defines for the max inputs commented out, firmware likely doesn't do anything with the inputs for the max switches. Your soldering is likely fine, since the min and max endstop switches would be on separate connectors on the RAMPS board.

I prefer the four springs approach. It allows me just get the Z endstop anywhere close, and then all fine adjustments are done in the four corners of the bed. Of course, I have thumbwheels on the corners now too. Leveling the bed takes me about two or three minutes. The stock makerfarm approach can easily take 20-30 minutes because of the complexity caused by the fixed corner and the multitude of tools required to adjust the other corners.

Trying to remember all your changes, did you print those thumb wheels out?

[printbus]

Trying to remember all your changes, did you print those thumb wheels out?

Yes. The ones I have now are http://www.thingiverse.com/thing:29782. On the 8-inch printer, I did have to file the diameter down a bit for the one at the left rear to clear the frame. Other thumbwheels may not have that problem.

The BED LEVELING post describes how the screws are locked to the heat bed, leading to a tool-less approach to the bed leveling. Note that I did replace the corner bolts with longer ones too, mainly since the silicone trivet I use for bed insulator is pretty thick. The thumbwheels originally used in that post didn't have much knurl, so they were later replaced.

EDIT: Of course, if you plan to implement ABL pretty quickly on your printer, the concerns on how hard it is to level the bed won't be as important to you.

[usarmyaircav]

My current status:
On a Lets try it and see note, I moved the z end stop to the side of the extrusion, and then tilted it forward to make sure that the endstop switch would hit the frame of the x idler, which it did!!!!! YES!!!!! So I was able to adjust it to get it down maybe 1 or 2 mm, and then attempt to level the bed. I did it fairly quickly and I think it is level. I need to get it down to the paper thickness level, and I agree moving that whole end stop is not accurate. So I will get it adjusted closer.
Do I then attempt to print the test cube, or calibrate the e-steps? So looking forward to actually printing something!!!

[usarmyaircav]

Somewhere I thought I had seen printbus say that the hot end should be tightened again while hot, but I can't find that. My i3v10 came with a shroud for the fan like that looks like the current E3d6 shroud (but in ABS), so access to all except the nozzle is blocked. Do I take the shroud off and just have the fan there to have access to tighten the hotend?

Could someone recommend starting hotend and bed temps for ABS?

What screw sizes are used to mount the haswell type power supply, the M3's are too loose so I am suspecting they are not metric.

[printbus]

1. Somewhere I thought I had seen printbus say that the hot end should be tightened again while hot, but I can't find that. My i3v10 came with a shroud for the fan like that looks like the current E3d6 shroud (but in ABS), so access to all except the nozzle is blocked. Do I take the shroud off and just have the fan there to have access to tighten the hotend?

2. Could someone recommend starting hotend and bed temps for ABS?

3. What screw sizes are used to mount the haswell type power supply, the M3's are too loose so I am suspecting they are not metric.

1. Yes, any all metal hot end should be tightened up while hot. This will help ensure that joints remain tight (and leak free) as the different metals (brass nozzle, aluminum block and stainless steel barrel) heat up. So yes, take off the shroud for the bit of time needed. On my latest rebuild, I tightened things with the hot end loose on the heat bed.

2. The few things I've done in ABS have been at around 235 degrees.

3. I'm not familiar with Haswell, but most of these supplies are clones of Mean Well, which use M4 mounting screws.

[usarmyaircav]

Thanks Printbus, I meant Mean Well. LOL

What about bed temp?

[printbus]

...What about bed temp?

For ABS, I have varied between 90 and 110, but I didn't spend enough time with ABS to figure out the magic settings for the filament I have. What you're battling is figuring out what works best to hold the print to the print bed. Since ABS shrinks quite a bit when it cools, larger flat things will have a tendency for the corners to curl up and lift off the bed. The more airflow you have flowing around the print and the cooler your room temperature is, the more of a challenge you'll have with this. What you're using to cover the print surface (kapton tape, ABS slurry, etc.) is also a factor in how well the print holds. I think everyone has to figure these details out for their particular situation.

[usarmyaircav]

how long should it take the bed to get up to 110 temp using the relay, seems really slow. so far 27 minutes to heat the hotend and then get the bed to 78 degrees.

[printbus]

how long should it take the bed to get up to 110 temp using the relay, seems really slow. so far 27 minutes to heat the hotend and then get the bed to 78 degrees.

That's a long time. For comparison, my hex hot end goes from room temp to 215 degrees in about 90 seconds and the 8-inch heat bed goes from room temp to 110 degrees in about eight minutes. Some suggestions on things to check -

• Make sure the power supply output stays at 12V when the heat bed turns on
• Make sure any screw terminals at the power supply and heat bed relay are tight
• Make sure the heat bed thermistor is secured well to the bottom of the heat bed (no gap)
• I'd try to make sure cardboard or other insulator you're using between the Y-bed and heat bed isn't pressing against the heat bed thermistor. If the insulator is touching the thermistor, the thermistor won't be properly reading the heat bed temperature. Cut a clearance hole in the insulator if required.

Beyond that, I'd suspect the gauge of the wiring used with the heat bed is on the small side, and you're not applying the power you could be to the heat bed. You could verify this by measuring what voltage is actually applied at the heat bed itself. Do you feel any of the heat bed wiring getting warm? That would be another sign of power being lost in the wiring. As I understand it, the 10-inch heat bed can draw as much as 18 amps. As heavy as 12-gauge wiring might be appropriate for that much current. Can you read the markings on the wires that came pre-attached to the heat bed? One thought would be to use at least the next larger size for the fixed wiring between the power supply and the heat bed relay where flexibility isn't important.

EDIT: I should probably note that my hex hot end is not running the original cartridge heater, aluminum block or thermistor. I use silicone heatsink compound on the cartridge, and my hot end aluminum block is insulated on all sides with kapton tape. My hot end warm up time may not be comparable to the usual config.