12.5" F5.5 自製牛頓望遠鏡 (08) ---- 幼磨(V)

[豆豸苗]

磨 1200 號時, 全程都用唔洗鏡0既方法.

終於.................

試過兩次癡住左主鏡同工具板!!! ^^||||

磨左半個鐘頭檢查砂眼. 好奇怪, 發覺中間同邊緣0既砂眼比兩者之間0既區域幼...
真係有0的懷疑, 咁0既現象係因為唔洗鏡咁加砂, 搞到0的砂唔係咁平均所致.
於是阿華又用油筆呢招, 幫我0係塊工具板上面畫左個米字.
我再磨0既時候, 發覺個米字0既中間磨走得快0的喎........!!?? 而外面要轉四五個方向咁磨先漸漸磨走. 不過都係唔理咁多住, 繼續先.
磨多個零鐘之後, 0的砂眼又平均番喇.

跟住係 2000 號~

[specsman]

好想睇下妳既製成品

[Chanlunlun]

跟住係 2000 號~

Dear Miss BeanKitty,

There is no need to go through the #2000 stage as polishing will get finished in 4 - 5 hours at #1200 surface. You need at least 2 hours to get over the #2000 stage and that will not save you more than 2 hours for polishing. All in all you spend more time - it is uneconomic to grind #2000.

In addition more fine grinding means more chance to jeopadize your mirror to chip off, sticking, sleeks ....etc.

If you are done in #1200 then go staright to the polishing stage.

Best regards
Chan Yuk Lun