Safarir
(Charles)
I decided that I wanted to fix the power feed on my Excello 602. The 602 have a power feed mounted on the knee which is basically a DC servo motor and a speed controller. The servo is constantly turning and when the lever on the saddle is engaged, a spline shaft is engaged that connect to the lead screw via a gear near the hand wheel.
On my machine, the electronic seem functional but I am missing some hardware:
- Spline shaft
- Spline shaft gear
- Feed coupler
- 2x Trust washers
I have yet to figure out how I will make the spline shaft or the feed coupler, so I decided to start with the gear.
This picture show the gear attached to the lead screw. The hole on the right is the bronze bearing for the spline shaft. I need to make the matching gear, so first step is to identify the gear I already have.
Some quick math reveal that it is a 30 teeth gear ;p
Also, with it diameter of 2", it seem to be a 16DP. After measuring the distance between the axis of the leadscrew and spline shaft, I calculated that the matching gear should be 14 teeth.
The last question is what is the contact angle ? I did not find any good reference on how to measure that, so I started by scanning the gear with a document scanner.
I then generated a 14.5° and 20° contact angle gear in fusion360 and compared the profile:
14.5°
20°
From those picture, the 20° contact angle seem a better fit, which is quite surprising to me as 14.5° seem more common. Does someone have a better way to identify the contact angle ? Those gear cutter are pretty expensive, so I don't want to end up buying the wrong one.
On my machine, the electronic seem functional but I am missing some hardware:
- Spline shaft
- Spline shaft gear
- Feed coupler
- 2x Trust washers
I have yet to figure out how I will make the spline shaft or the feed coupler, so I decided to start with the gear.
This picture show the gear attached to the lead screw. The hole on the right is the bronze bearing for the spline shaft. I need to make the matching gear, so first step is to identify the gear I already have.
Some quick math reveal that it is a 30 teeth gear ;p
Also, with it diameter of 2", it seem to be a 16DP. After measuring the distance between the axis of the leadscrew and spline shaft, I calculated that the matching gear should be 14 teeth.
The last question is what is the contact angle ? I did not find any good reference on how to measure that, so I started by scanning the gear with a document scanner.
I then generated a 14.5° and 20° contact angle gear in fusion360 and compared the profile:
14.5°
20°
From those picture, the 20° contact angle seem a better fit, which is quite surprising to me as 14.5° seem more common. Does someone have a better way to identify the contact angle ? Those gear cutter are pretty expensive, so I don't want to end up buying the wrong one.