MakerFarm 8" i3v Prusa build by Printbus

[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.

[Roxy]

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.

I tried this and the heat sink grease I used ended up drying out and getting crumbly. Did I just use the wrong grease?

[printbus]

I tried this and the heat sink grease I used ended up drying out and getting crumbly. Did I just use the wrong grease?

It's hard to say. If the compound was metallic in color, I believe drying out is what is intended - improving the bond of the remaining silver-laden part. The problem with that is any mechanical movement breaks the bond and the compound has to be cleaned off and reapplied. I used the old school white grease that seems to never dry out. Just a bit along the edge that the set screw will push against the block.

[usarmyaircav]

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.

What I found out is that the wire I used from the PS to the relay is not the right gage. It was way hot, so I shut it down. I will make a run to Lowes tonight to get some 12gage wire. It was after I had posted this that I decided to check for loose wires and when I grab the wires coming in to the relay it was like "wow is that hot" Thankful nothing seems to have melted down.

[printbus]

What I found out is that the wire I used from the PS to the relay is not the right gage. It was way hot, so I shut it down. I will make a run to Lowes tonight to get some 12gage wire. It was after I had posted this that I decided to check for loose wires and when I grab the wires coming in to the relay it was like "wow is that hot" Thankful nothing seems to have melted down.

Another option for you would be to double up on smaller gauge wires.