Had my machine for 1 1/2 yrs. I’ve tried tightening all belts. But still have a problem when engraving. Since I’ve had the machine I’ve replaced the carriage plate wheels and tightened that belt with no problems(about 4 months ago)
Then 2 days ago I tried engraving this as a gift. You can see on the word Fun how the lines are not straight. The first photo shows my problem. And the second photo is the same project done 6 months ago where all s fine.
I’ve checked for debris etc. Now I’m wondering how long do the belts last? They don’t appear worn or torn.
Your wiggle looks consistent which suggests that it’s something like debris or perhaps a stepper motor rather than a belt gone bad. Have you also checked all the rails and wheels as well?
My Glowforge is three years old now I think with no wear on the belts. I have 3D printers that use the same belts that are over five years old and heavily used with no wear on the belts. If you have a fire and the belt gets damaged it will have a problem, but a properly tensioned and installed belt should not fail. Sometimes the mounting will fail, but the belt itself should not. They are usually kevlar reinforced and will last a really long time.
There are (very broadly speaking and in this context) two types of motors – continuous motors and stepper motors. A continuous motor is what you probably think of when you think of an electric motor. You apply electricity to it, and it turns. More electricity equals turning faster, and it stops when you stop applying electricity. With a stepper motor, when you apply electricity to it, it takes a single step – i.e. it turns a small fixed amount. To make it keep turning, you have to stop applying electricity, and then start applying it again to make it take another step. To make it turn faster, you send these pulses faster.
Continuous motors are cheaper and are used anywhere that you don’t really care how much it turns, or where you have some other method of measuring how much it’s turned. Toy cars, a sewing machine, a washer & dryer are all examples of where a continuous motor would be used.
Stepper motors are used anywhere you need precise control of the distance moved. 3d printers, laser cutters, CNC machines, all use stepper motors.
At the finest setting, the Glowforge can engrave at 1355 lines per inch, which implies that each step of the motor that moves that axis of the laser head moves it at 1/1355 inches. The only way to get that fine level of control is with a stepper motor, not with a continuous motor.
(*) There are many other ways of classifying motors, and way more than two types, but those distinctions are not relevant to the question of “what is a stepper motor”.
Like the belts, stepper motors generally don’t fail.
With the machine off, slowly roll the gantry forward and back, and the head side to side - they should move smoothly.
My first guess is there is a problem with a wheel or a belt pulley.
