| ??? 09/13/10 06:55 Read: times |
#178534 - Head has constant speed w/o steps even with stepper motors Responding to: ???'s previous message |
Step motors are great. But the mechanics isn't perfect, which means that everything must be run at a perfect constant speed or the jitter will be noticeable in the printed output. The stepper motor allows you to know where you are, but the head will move in a continuous motion without any steps because of the mass. Hence the need for careful timing. Especially if using a staggered head, where the needles/nozzles are mounted like:
x x x x x x x x What isn't visible in the ASCII drawing is that in a staggered head, there is significant overlap in vertical direction which is the reason the needles/nozzles can't be mounted directly above each other. It's interesting that the animated image shows an 'a' that is missing dots. It looks more like a character printed in draft mode, but the feature with draft high-speed mode normally only exists on 24-pin printers where the draft mode only fires every second time to instead allow twice as high head movement speed. |
| Topic | Author | Date |
| I/O pin extension | 01/01/70 00:00 | |
| Start by specify your need | 01/01/70 00:00 | |
| you really have to list down the full requirements | 01/01/70 00:00 | |
| A suggestion | 01/01/70 00:00 | |
| Specefic Requirements | 01/01/70 00:00 | |
| Why relays? | 01/01/70 00:00 | |
| But dot matrix printers normally don't have X*Y array head | 01/01/70 00:00 | |
| Only need *one* column of dots! [ED] | 01/01/70 00:00 | |
| Head has constant speed w/o steps even with stepper motors | 01/01/70 00:00 | |
| reply | 01/01/70 00:00 | |
| not helpful! | 01/01/70 00:00 | |
| Necessity of relays | 01/01/70 00:00 | |
| Relays are not necessary | 01/01/70 00:00 | |
| What's a "design"? | 01/01/70 00:00 | |
| Discrete or integrated | 01/01/70 00:00 | |
| So what's the reason for a slow ctar-at-a-time head? | 01/01/70 00:00 | |
| Printer Purpose | 01/01/70 00:00 | |
| Still no specific reason for a matrix! [Ed] | 01/01/70 00:00 | |
| More care while finding solution | 01/01/70 00:00 | |
| RE: "many others" | 01/01/70 00:00 | |
| Smaller than a relay | 01/01/70 00:00 | |
Relays Take Drivers Too | 01/01/70 00:00 |