Solved Hot end fan-questions

After much troubleshooting of stuck filament in my R1+ and reading many of the comments posted, I have determined that my Hot End Fan is not doing it's job. So I am going to replace it. But before I do, I have some questions:

1. After laying doing two really crappy layers, the inside hub of the fan is really hot. Does anyone know if this is normal or maybe the bearings are shot?

2. Does the fan blow against the hot end or draw air from the hot end?

3. What is the cfm of the fan?

4. What is the part number of the fan they, Robo3D uses?

5. Where do you get those connectors? Part Number?

6. From the posts it appears that it is a 25mm x 25mm x 10mm 12VDC fan. Is this correct?

 

Yeah, the problem here it appears as if they did not leave any service loop in the cable bundle. I doubt that I will be able to change the connector unless I remove the cable assembly and make a new one.

 

Just got through spending an hour looking at the JST web site for wire to wire connectors and did not find anything.

 

Thanks. The JST web site would not allow me to search for JST-SM. I had to look it up by alpha's....found it. Thanks.

 

OK, the fan is bad. Took it out and ran it on the bench. Draws 0.2A, specification is 0.1A. However, if I lay the fan flat, it runs faster and draws only 0.1A. After running in the vertical position, the hub of the fan, where I think the bearings are got REALLY hot to the touch. Clearly the bearings are bad. The part number for the fan is YY2510H12S. You want the fan to blow onto the hot end, not draw heat away from it. Looks like Amazon has some. Too bad Robo3D doesn't have any R1+ in stock at their facility. I was going to drive down there and pick up two for the Valley Center San Diego County Library. Looks like that is not going to happen.

 

Fan connectors: Part number SMR-O2V-B (Black) or SMR-02V-N (Natural). The socket contact appears to be SHF-OO1T-0.8BS. You will need a special crimper to crimp the socket on to the wire. All are readily available at Digi-Key for just pennies; then comes the shipping costs!

 

Thanks everyone for the input. I have ordered three fans since they seem to be a weak point. I have also ordered connectors but they will not be here until next week.

 

The fan has been replaced. Just spliced in the old connector since the new ones have not arrived yet. The first print, while small is OK. The whole unit is MUCH quieter now causing me to think that the original fan had bad bearings from the start. Another point is I had to lower the extruder temperature by 5 degrees C. It seems that the extruder is working really good and was originally designed. I had a lot of excessive material coming out of the extruder while it was warming up and the first two layers had excessive material. The only thing left to do is secure all the wires back to where they were. Not looking forward to that.