Problems with stock gear with no screw on Ender 3 pro
I am very new in the 3D printing scene.
After a lot of searching for my specific problem (and didn't find any answers, of course) I decided to reach out.
I bought a Creality Ender 3 Pro in November and after a few days of lovely prints
I decided to upgrade the printer with a glass bed and "Aluminum Dual Gear Pulley Dual Drive Extruder Kit".
The Problem, as you might expected already, is with the installation of the dual gear extruder. I have watched a dozen of YouTube videos, and all of them have something I don't – a screw in the stock gold gear on the extruder motor.
How can I install the Aluminum Dual Gear Pulley Dual Drive Extruder Kit if I take the gear out? Should I try remove it with force?
Please if someone has come across the same situation, that there isn’t a screw In the stock gear on the extruder motor and mange to take it out, please tell me.
I'm adding a picture so you understand what I mean.
Welcome to the 3D Printing Stack Exchange! I'm having trouble understanding what the problem is, does the instruction manual that the printer came with (likely on the included SD card or USB flash drive) mention the grub screw there?
no. the problem is to remove the stock golden gear that sit on the extruder motor, so i could installl the "Aluminum Dual Gear Pulley Dual Drive Extruder Kit" ...
Could you add a picture of that kit and the part you need to replace the stock gear with?
this is the kit: https://www.banggood.com/Upgraded-Aluminum-Dual-Gear-Pulley-Dual-Drive-Extruder-Kit-For-Creality-CR-10-or-CR-10S-or-CR-10S-Pro-or-Ender-3-or-Ender-3-Pro-3D-Printer-p-1469345.html?rmmds=myorder&cur_warehouse=CN, and the part is the golden gear in the 3 1st pics i have added...
I had the same problem with the pressed on gear. With WD40 and een center punch the gear came off allright. The next problem was the shaft that is to short and perfectly round. With a small grinder (Dremel) I created a flat spot. I carefully tapped the shaft from the bottom of the motor until it was sticking out enough on the top side. Now is works perfectly with my dual extruder.
Heating it proved futile in my case (I didn't have a blowtorch either), I was able to get the gear off by using a Dremel, I also flattened a small side for the screw.
However, to my extreme frustration, I found out that the actual height of the shaft is not long enough to reach the dual extruder's filament hole and thus had to order another motor.
I had exactly the same problem with an Ender 3 Pro I bought a couple of weeks ago (Mar 2021) and I was able to remove the gear easily with a small gear/bearing puller... take a look at Amazon and you will find plenty of selection.
The 3-arm puller works better as it's much more stable when pulling the gear (this is the one I have). Both work in the same way; the arms/jaws attache to the bottom of the gear and the tip of the top screw pushes the motor shaft down.
Do you have a photo of the tool and/or a diagram or description of the process? It would improve your answer.
Thanks for your comment @Greenonline ! Sure, I'm attaching a couple of pictures for the 2 most common options you can find. The 3-arm puller works better as it's much more stable when pulling the gear (this is the one I have). Both work in the same way; the arms/jaws attache to the bottom of the gear and the tip of the top screw pushes the motor shaft down.
If you cant see any grub-screw on the extruder gear, it's likely that it has been permanently press-fit onto the motor shaft. It is possible to remove the gear if you have something like a Dremel to cut it off, however, do note that it would be a permanent modification, and that your warranty (if you had any) would be void. If you do go this route, be careful not to Dremel into the shaft of the motor, as this would likely cause the new gear to not fit properly.
If this is a new printer, I would recommend assembling it with the stock extruder assembly first, and ordering a secondary extruder motor without the gear press-fit onto its shaft. Then you could swap them out and not need to worry about damaging the existing motor.
This brass extruder gear is either press fitted (see other answer) or hot crimped onto the shaft. Brass has about twice the thermal expansion rate as stainless steel, so you could heat the gear while cooling the shaft (e.g. stepper upside down with the shaft in water, heating the gear with a small torch lighter, a makeshift aluminium foil shield could be used to protect the stepper base) to get the gear off.
Grinding it off would be easier (or even more easy is to buy a new stepper motor) as when you get the gear off, the shaft is round, so you need to grind a flat spot on the shaft anyway to make sure the dual extruder gear can be screwed on tightly.