ERCF V2 Gear Box Back mod for common type CNC metal 80T pulley

Gear Box Back to use common type 80T CNC pulley

Let ERCF V2 use common type CNC metal 80T pulley

There is nothing wrong with 3D printed plastic 80T pulley, instead, I think it's one of the most useful invention of the year, because 80T metal pulley is quite expensive, now that we can print it, it makes our projects cost less. also we can print it using different colors.

For ERCF V2 kit for sale, some seller provides a speical made 80T CNC metal pulley, which is very special, 
not to be confused that it's the same as a common 80T pulley, it's not.
* it has smaller screw mounting body, 
* it has a smaller main body diameter comparing to normal 80T pulley, also the gear has no wall to block the belt from moving out.
therefore it can fit in the original "gear box back" part.
It can be bought with higher price than normal type 80T CNC pulley.
The cheapest 80T CNC common type pulley is only about 4-5$.

If you want to use a common type 80T pulley, it has 20CM diameter screw mount body, and 55mm main body diameter, both are too big to fit in the ERCF V2's gear box back part.

This modded part change below things:
1 it has a larger room scrwe mounting body (20mm size)
2 it has room for 55mm main body.
3 the back of the part now has a larger room and thicker back, so it must have some cut out, so it can fit with the 2020 aluminum extrusion.

to make the gear works with the NEMA arm part, make sure the gear doesn't move toward the NEMA arm part and touch and grind, a 5.4mm 3D printed washer is also needed.

note, there is a different type of 80T pulley which has a much much larger screw mount body diameter (30mm), that won't fit, not a chance, too large.

The cheapest 80T CNC common type pulley is only about 4-5$.
so this upgrade is a good option in case you want a metal 80 pulley, and not want to make a 3D printed one ( some work is required to make a 3D printed 80T pulley).

parts needed:

M5 0.5mm thick nylon washer - or 3d printed, but I think nylon is better, inside gear box back, between 80T pulley and MR85ZZ bearing. to make sure 80T pulley doesn't touch the gear box back part.
80T CNC pulley common type, 20mm diameter screw mount body.

Print Setting
please use support for better result.
petg abs
40% infill
4 parameter
 

ERCF V2 Gear Box Back mod to use common type 80T CNC pulley

In ERCF V2 Original design, 3D printed 80T pulley

There is nothing wrong with 3D printed plastic 80T pulley, instead, I think it's one of the best and most useful invention of the year(from ERCF V1 ), because 80T metal pulley was quite expensive at that time,  now that we can print it with plastic, it makes our projects cost much less. Also we can print it using different colors to make project looks better. 

just need to destroy a 20T pulley and some work is required to make a 3D printed 80T pulley, and it may not be perfectly straight if not made with care and skills.

Special CNC 80T pulley for ERCF from some sellers

For some ERCF V2 kit for sale, some seller provides a specially made 80T CNC metal pulley, which is very special, and not to be confused that it's the same as a common 80T pulley, it's not.
* it has smaller screw mounting body, 
* it has a smaller main body diameter comparing to normal 80T pulley, also the gear has no wall to block the belt from moving out.
therefore it can fit in the original ERCF_V2 "gear box back" part.
It can be bought with higher price than normal type 80T CNC pulley ( about 1.5X to 2X of the cost)

 

Normal type 80T CNC metal pulley

Similar to the 80T metal pulley we use in Voron 2.4 Z motion system ( but maybe smaller screw mount body – only 20mm diameter)

The good about this part:

• no need to build your own 3D printed 80T plastic pulley, save some work
• error free, it's CNC made so naturally straight and perpendicular in every way.
• It has teeth wall or belt block or belt guard, the belt won't fall of the pulley
• metal, should last forever
• now it's much cheaper than 3 years ago, and much cheaper than the special type cnc pulley

If you want to use a normal type 80T pulley, it has 20mm diameter screw mount body, and 55mm main body diameter, both are too big to fit in the original ERCF V2's gear box back part.

If you want to buy some, make sure to buy the one with 5mm bore/middle hole, and smaller screw mount body  (20mm Diameter).

This modded part changed below things:

1. it has a larger room for screw mounting body (20mm diameter size)
2. it has room for 55mm main pulley body.
3. the back of the part now has a larger room and thicker back, so it must have some cut out, so it can fit with the 2020 aluminum extrusion.

to make the gear works with the NEMA arm part, make sure the gear doesn't move toward the NEMA arm part and touch and grind, a 5.4mm long 3D printed washer is also needed.

note, there is a different type of 80T pulley which has a much much larger screw mount body diameter (30mm), that won't fit, not a chance, too large.

The cheapest 80T CNC common type pulley is only about 4-5$. I think it's due to it's longer history and larger scale of market. a lot cheaper than the special one mentioned above.

so this upgrade is a good option in case you want a metal 80 pulley, and not want to make a 3D printed one ( some work is required to make a 3D printed 80T pulley, assembly etc).

Files:

stl files are provided

stp file is also provided

f3d provided but missing external reference ( pulley, gear box front part etc)

cannot export to f3z 

Parts needed:

M5 0.5mm thick nylon washer - or 3d printed, but I think nylon is better, inside gear box back, between 80T pulley and MR85ZZ bearing. to make sure 80T pulley doesn't touch the gear box back part or bearing.
common type 80T CNC metal pulley , 20mm diameter screw mount body. M5 bore/middle hole.

Print Setting

please use support for better result.
petg abs
40% infill
4 parameter
 

Assembly

•  see picture
• as original design, insesrt bearing in the gear box back part, insert 0.5mm thick washer (nylon or print)
•  insert 80T common type CNC pulley, make sure pulley couldn't move and touch the gear box back part.
• when need to install or adjust the 80T pulley's mounting scrub screws, there is a cut off to do so in the gear box back body, just rotate the pulley a bit.
•  insert 5.4mm tall 3D print washer.
•  install the original ERCF 2 NEMA motor arm as the original design.
• rotate, push , move , make sure the pulley doesn't touch the NEMA arm part.
•