New Extruder Drive Gear

[Slipshine]

Running the new gear. I like the larger set screw compaired to the original. It is much more sensative to adjustment. I have had the most sucess feeding filament in until you see it in the gap above the hot end. Then back it out and measure the widest area on the filament. If it has smashed it to more than 1.85 you will need to back off the screw some more, trim the smashed area off and try again.

I have tried with petg and pla. Trying a long petg overnight.

[Tim]

I ran into a problem. . . The set screw on the old drive gear won't come out. The allen wrench is tiny; first, the wrench wanted to bend, and when I applied torque closer in, all I managed to do was to strip the set screw. So now what's the best approach? Drill it out?

[jimc]

Yeah on the older gear that tiny set screw is a pia. Just drill it

[jimc]

tested the gear out tonight with ninjaflex. seems to work as well or maybe a hair better than the old gear. i honestly didnt see too much of a difference. it had enough grip to buckle over the filament if you extruded too fast so there is plenty of grip there. i was able to do that with the old gear as well. for tpu it seems to work just fine. i still want to try with the bridge nylon. maybe tomorrow night ill get to that.

[ErikAkia]

I have a variation of Tim's twin extruders with E3D V6 hot ends. I installed the new gear on one extruder and ran some extrusion calibration cubes, It did not appear to change it much. I ran a dimpled ring calibration test with normal settings in black PETg http://www.thingiverse.com/thing:247162. I then ran the same test on the extruder with the old gear. Then I switched the gears on the extruders and ran the test again. To my eye there is no difference in ringing between the new and old gear. I have been using the same tension setting and the new gear has performed fine with both PLA and PETg. So far I have seen no evidence of the teeth clogging.
I will try and play around with the flex filaments this coming week.

[Slipshine]

After a weekend of printing with the new gear it performed better than expected. When I first saw those tiny teeth I did not expect much.

As stated earlier the nut securing the gear to the shaft is larger. This is a big plus as the other one was sketchy at best.

The added slot and brush for cleaning the gear is a nice touch.

With the fine teeth getting the tension set just right is more difficult than with the coarse gear. This may be more difficult for new users.

I have had the most sucess feeding filament in until you see it in the gap above the hot end. Then back it out and measure the widest area on the filament. If it has smashed it to more than 1.85 you will need to back off the screw some more, trim the smashed area off and try again.

After getting it set I was able to switch between Pet-G and Pla without additional adjustment.

The amount of pressure on the adjustment screw is minimal. It is so light I will suggest that if you are using the new gear you may want to consider a lock nut so when under heavy vibration or filament change it doesn't move.

metric-bzp-nylon-lock-nuts.jpg (15.56 KiB) Viewed 11692 times

So far I have printed 1lb of Esun White Pet G and 1/4 lb of generic natural PLA that I have had for 3 years. There have been no issues. I see no reason abs wont work but I have not had a chance to print with it. I will try ABS this week unless someone has already got to it.

Jim has done the ninja flex which I am grateful for as I don't really like using it.

Long term I am concerned that the grip will diminish due to wear but only time will tell.

Hope this helps.

[zemlin]

So far I'm finding the new gear to be touchier about the pressure adjustment - needing attention when changing materials - and I haven't seen any real benefit.

[ErikAkia]

I printed the 3DBenchy boat last night in Ninjaflex on the new gear at 20 mm/s. I am not sure if I have finally dialed in the Ninjaflex settings or if it is the new gear but that was the best one I have printed. I will switch out to the old gear tomorrow and print it on the old gear with the same settings (after calibration) to see if it performs as well. Then I will speed it up until it breaks.

My extruder does not use the bolt to create tension as I have designed it to use a 3D printed spring clip. which means that I am using the same tension that I did for the old gear and between filaments. I have not had any issues with the tension so far.

[zemlin]

Tried running Taulman PCTPE tonight. Gave up on the new gear and went back to the old. Filament kept slipping. Diameter varies quite a lot on this stuff. I drilled out the extruder drive housing to 2mm just to be sure the filament wasn't just getting stuck.

[ednisley]

Diameter varies quite a lot on this stuff.

From what I saw, that will be the main problem with the new gear: it depends on the springiness of the plastic lever arm to maintain pressure as the filament diameter varies. Unfortunately, the plastic isn't a good spring, doesn't have a lot of compliance, and deforms slowly under continuous pressure.

I think the smaller teeth on that gear will require a real metal spring between the lever arm and the screw head to apply a constant force. A coil spring around a longer bolt would be a quick-n-easy fix, if you have a really stiff spring.

If somebody wants to design a plastic drive body carrying a spring-loaded metal lever arm, I'm in ...