單體船狂熱／MONO MANIA 3/3（船姿調整及硬件安裝，並非指電船）

leo_home · 发表于 2013-6-20 02:21

本帖最后由 leo_home 于 2013-6-21 00:20 编辑

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June 1998 Roostertail
MONO MANIA BY JOHN FINCH
1998年6月Roostertail
單體船狂熱
作者：John Finch

We talked about trim tabs in the first issue of the newsletter and then struts in the second issue. Now lets get into prop walk and add all three issues together for a smooth running Mono.
我們在第一期討論了壓水板，在第二期討論了軸支架，現在來討論槳步行，及把這三個課題加在一起，以獲得順暢航行的單體船。

Prop Walk
槳步行

Prop walk is the action that causes the model to veer to the right when at full speed. This is caused by the propeller dragging the transom to the left. The transom is dragged to the left because the prop, rotating in counter clockwise direction, tends to walk like a paddle wheel in that direction.
槳步行是船在極速航行時，使船轉向右的動作，這是因為螺旋槳把船尾拖拉向左邊所至，因為螺旋槳以反時針方向轉，有如一個腳踏車輪，把船尾拖拉向左邊。

As a visual aid to understanding propwalk, visualize the propeller spinning counter clockwise as viewed from the rear of the boat. Draw a line from the left to right through the middle of the prop. The line divides the propeller into two halves; an upper half and a lower half. Blade movement on the upper half goes right to left. Prop blades on the lower half travel left to right. On a surface drive model the lower half of propeller rotation has a strong bite in solid water. The upper half, however, is partially above the water and has less bite in the water, so the prop paddle wheels to the left. With a subsurface setup, the strut blade can cause a stream of air bubbles to interfere with good prop bite in the upper half of rotation, which allows propwalk to run wild.
以一個可視工具幫助理解槳步行，從船尾方向看，從左至右畫一條線，經過螺旋槳軸心，把槳分為上下兩部份，槳以反時針方向旋轉，線把槳分為兩半，上半部和下半部，上半部的葉片從右移向左，下半部的葉片從左移向右，在表面推進（半浸槳）的船，槳下半部能咬緊實體水，但槳上半部是部份在水面以上，較難咬緊實體水，所以槳腳踏車輪轉向左，在水下推進（全浸槳）的船，軸支架引起氣泡串流，使槳上半部較難咬緊實體水，做成槳步行。

Compensating for Prop Walk
補償槳步行

One way to compensate for prop walk is to bend the strut to the left, much like an outboard engine that is turned to the left to make the boat turn left. This method can cause other problems, though, so pay attention to detail. If your strut exits the boat dead center out of the transom, twisting the strut to the left will put the prop left of the centerline of the boat. The prop being to the left of the center of the boat may cause the boat to chine walks badly after the adjustment. Reason being, the prop lifts the left side of the boat more than the right side. With torque lifting the left side of the boat along with the prop being off center, the left side of the boat is lifted easily and can cause the boat to rock violently.
其中一個補償槳步行的方法是，把軸支架（STRUT/STINGER/俗稱老鼠尾）向左彎曲，正如掛舷外機的船把發動機調至向左，使船轉向左，雖然這樣，這個方法會引起另一個問題，所以需要注意細節。如果軸支架位於船的中心線，把軸支架彎曲向左，會把槳置於船中心線的左邊，調整後，槳位於船中線的左邊，可能使船CHINE WALK，即使槳位於船的中線，發動機的扭力都是提升船的左邊，與此同時，加上槳提升船的左邊多於右邊，船左邊很容易被提升，船會嚴重搖擺。

A Better Solution
更佳方法

The biggest cause of propwalk in a Mono is the strut blade. When water hits the strut blade, it is separated and runs on both sides of the strut blade. The problem is that it doesn't immediately blend back together after it passes the trailing edge of the strut blade. A trail of broken water leaves the strut blade but does not become a solid water mass for some distance. As I said earlier, the upper half of the prop rotation is located directly behind the strut blade and rides in the disturbed water flow.
單體船槳步行的最大成因，是軸支架的片狀結構，當水經過軸支架時，被分為兩半，流過軸支架，問題是流過軸支架片後緣後，並非馬上接合成實體水，斷開的水流尾隨軸支架，在一段距離內，沒接合成實體水，早前我已經說過，螺旋槳的上半步，正位於軸支架片之後，工作於受干擾的水流。

The solution is to extend the strut hub far enough behind the strut blade so that water has time to join back together before entering the prop blades. I find that an inch is usually enough. This works with surface drive models too, because the new prop location far behind the transom of the boat puts the prop deeper into clean water. While the extended prop shaft length does allow more water to hit the top half of prop rotation, and the prop becomes more submerged, propwalk is reduced and increased speed is the result.
解決方法是延長軸支架中樞，至軸支架片後足夠遠的距離，使水在進入螺旋槳前，有足夠時間接合，我發現通常一英寸就足夠，這個方法亦適用於表面推進（半浸槳）的船，因為槳的新位置遠離船尾，槳位於較深而安靜的水中，延長軸支架，讓更多水流到槳的上半部，槳加深浸入深度，槳步行減少了，結果是速度上升。

An advantage is also seen in the extended prop shaft as the prop, when further from the transom, tends to keep the bow positioned without the need for radical trim tab adjustment. As the bow rises, the prop gets deeper in the water and pushes the bow back down into the water. That is top secret info!!!!! If you get the distance just right, it takes less trim tab to keep a fast boat on the water. I have found that three to four inches work best for me, depending on the model. If you get the prop too far behind the transom you will know it, because the boat will hop, especially in the corners.
延長軸軸支架還有另一優點，當槳離船尾較遠時，會趨向使船頭更穩定，可減少調整壓水板的需要，當船頭升高，槳會加深浸入深度，把船推回至原位，這是最高機密！如果你能使長度剛剛好，可以較少依靠壓水板調整，就能穩定快船於水面，我發現3至4英寸最適合我，視乎那一條船，如果槳在船尾以後太遠，你會發現船會跳動，特別是轉彎的時候。

In an earlier issue I said that I prefer a strut angle that is parallel to the keel, and that is a good benchmark for most boats, If however, you have a surface drive model that is really hauling the freight, some negative angle and a long strut hub will give you the control you need to drive in the 55 MPH range with full control.
在早前發表的文章裡，我曾經說過較喜歡出軸與龍骨平衡，對大部份的船，這是個好的基準點，但如果你有一條表面推進（半浸槳）的船，因為要在時速55英里的速度下穩受控制，而很需要把軸支架調至負角度，及有一個長的軸支架。

A combination of slight strut twist and an elongated strut hub used together will sometimes give the best mix in compensation for prop walk. If you plan on twisting the strut, build the stuffing tube so that it exits just to the right of the centerline at the transom, so that when you bend the strut to the left, the prop ends up dead center on the centerline of the boat.
輕微的彎曲軸支架，同時用上加長軸支架中樞，有些時候可最佳補償槳步行，如果你計劃扭曲軸支架，可把軸支架安裝稍微向右偏離中心線，於是當你完成向左彎曲軸支架時，槳剛好位於船的中心線。

Good luck in taming that wild beast we call a Mono!
我們稱這條野獸為“單體船”，祝你在馴服它時有好運！

英文原文網址：
http://www.rumrunnerracing.com/feforums/showpost.php?p=261203&postcount=4

一看便愛上本文，連看數晚，覺得很好，想聯繫原作者John Finch問准翻譯轉載沒成功，再問RumRunnerRacing.com負責人Don Wollard，請求把消息轉給John Finch，Don回覆說，John的文章是公開的，才開始翻轉載。曾經問5imx樓主，是否適合登在動力艇新手掃盲貼裡，沒得到回覆，相信是不適合，才發新貼，所以翻譯本文並非一帆風順。這文章與

RC BOAT HULL ATTITUDE
http://bbs.5imx.com/bbs/forum.php?mod=viewthread&tid=793360&extra=page%3D3

可互補不足，RC BOAT HULL ATTITUDE有圖，也有助明白本文，兩文同看最有幫助。

原文1997年12月起刊登於IMPBA Roostertail期刊，作者John Finch是美國第一個打破時速60英里的運動員，John長期活躍於模型船界，曾經開辦工廠Twin Craft製造模型船殼，至發本貼為止，John都活躍於模型船界，本壇火熱下載的圖紙Wild Thing MONO，乃John Finch所設計供免費下載，著作有Basics of Radio Control Boat Modeling, Advanced R/C Boat Modeling

http://www.amazon.com/Advanced-R-C-Boat-Modeling/dp/0911295216

MAY 27 2009
Don Wollard RumRunnerRacing.com

I know this is long but worth the read. Don can always post this if he wants so it comes up or is a sticky or whatever.

This information was posted with permission from the author John Finch. This is a series of 3 articles that were published in the IMPBA Roosterail. Thank you for helping our hobby!

這些資訊經原作者John Finch授權轉載，那是刊登於IMPBA Roostertail期刊的，一系列共三編的文章，感謝對我們興趣的支持。