here is the 2nd part of what I am proposing. What I will do is work on a rough draft of a reference chart then as the data is compiled I can fill it in . Or another thought would be have the chart setup on your site and say I had info on my Yamato's drive system to the data board, I click on it and viola there's the chart and I just type in my info in the blank spaces. I say under Yamato class input under the blank spaces for Motor type - Shaft Size - Gear type/ratio - pinion size - Universal type - Prop Diam /# of Props - Type PROP - Blade # - Pitch A separate small chart could be for Rudders and Drive Battery System as there are a lot of people getting in are confused over the battery types and sizes.A subsection for things like cooling coils or other drive system accessories. OOOKAYY now I am getting another Coffee. Curt
First off, as I said before... I like your idea. However, I'm a little confused. For clarity, the purpose of this exercise is to calculate required propulsion specifications? So a person would come to your calculator.. & say: 1. I'm joining IRCWCC 2. I'm building a Yamato --the calculator would then say alright you need four, three bladed, 2" prop (or whatever it would wind up being) 3. You go out and see what 2" props are available. And write down the available pitches. 4. You would return to the the calculator & say I would prefer a 2" pitch. 5. --The calculator would then have to compute the required rpm & transmission ratios-- it would use an eq similar to: RPM X PITCH X [ 1 - (SLIP/100) ] (----------------------------------) = RATIO SPEED x C Where: RPM a positive number; the crankcase speed in revolutions-per-minute. RATIO a positive number; lower unit gear reduction ratio; the number of revolutions of the crankshaft to produce one revolution of the prop shaft. PITCH a positive number; blade pitch of prop in inches. SLIP a percentage, 0-100; index of propeller performance. SPEED a positive number; the boat speed. C a constant to convert inches-per-minute of revolution to boat speed; for miles-per-hour, 1056; for nautical-miles-per-hour, 1215.2; for kilometers-per-hour, 656. (See below for derivation.) (Reference: Visit this site) 6. The calculator would then say you need to buy M motor & create a transmission with R overall transmission ratio. I'm a little hazy on how we would find a motor RPM... Just have a look up table of motors @ rated battery Voltage? I'm not sure how to calculate prop slip. This would have to do with boat weight, speed, water temp, boat drag... VERY COMPLICATED!? What about drag disks?
Ok Scott you must be an engineer. Ahh actually not looking for a calculator just a reference chart based on member information of thier ships. Personal expereinece.Basically this is what I used in my drive to system and this is the result I got. Somebody goes to the chart sees 3 Yamatos and sees that one is using direct drive, another is using Gears and another is using a combo with an ESC.2 of the ships appear to be close in speed, or I want my ship to go a certain speed and Yamato#3 is using this set up to get this result. HE'S using 2 6V j600s on a traxxis gear 3:1 reduction -12 tooth pinion and I see hes using 2 4blade brass, 2.5 dia 25 pitch props. This is not exactly scientific but based on acedotes of people's experinece with their ships and what works for them As time goes on people contribute more data as they build more ships. The chart has to be readable on laymens terms to be understood. ie ONE SHIP uses 2 drive motors inboard while the another ship of the same class is using 4 motors and smaller props however both ships are running the same spee.This is basically what I am looking for.
Ok, outta the three of us... That made my head hurt. OUCH! *eyes go wide* As Ghostbusters you guys would be Ray and Egon, I'm Peter and that was too much for my brain. Did you get it figured out though? But Seriously, If you both can figure something out, don't try to explain it to me. Unless I have a hammer and a bottle of Tylenol. Keep up the good work! LOL And yes Curt, I believe Justin is an engine guy.
Back to serious discussion.. I just thought intermission was needed. Damn a 1/144 zero just crashed in my room. Just my opinion, but, wouldn't trial and error or what you already know, give you a good basis to draw from? My nickel less a dime.
trial and error "works" because you spend time forcing it to. It also has a tendency for errors or to provide "not the best" solution. What about the ships that no one has tried before? I'm really not sure what the best way of doing this is; but as an engineer, I am always inclined to find the "model" for why something happens... not just collect a bunch facts just in case one of them is needed. But on the other hand, finding an algorithm for this might not be possible (or at least possible at our level of fluid dynamics); in which case the only way to go is to create a "table". Even if we find an algorithm, we would have to test it. What I would rather do is start collecting data, and work on the mathematical model at the same time. That way at the end we could compare the calculated result to the actual result & see how acurate we were. Who knows, if we get it right; we might be able to calculate the drive system for any boat even if no one has ever created it yet. It should also be realized, this system will take time. I need a clear design before I move forward. Mockup screenshots would be nice, even if they were just make in MS Paint.
Scott my friend can assist me in setting up a table/chart. Once I get that completed I will send it to you and you can get a better idea what I am looking for here. Right now lets collect the data and once we feel we have enought to a start we can move forward on it. I have some data already collected but we need time to collect enough data. The chart needs to be set up and just a matter of people filliing in the blank spaces on the chart. Craig you should deactivate the AAA guns on NC so that no more Zeros attempting to land on your Shinano get shot down. Lol Darth Yoda IJNS YAMATO USS TENNESSEE
Curt I can't help it.... I'm in a fire fight here! Japan has the north part of the apartment ... Yanks have the south. This is not good, you should see what NC did to the pots and pans in the kitchen! There are Zero parts everywhere! Hope you chuckled! Table/chart good ... pleas send when completed... I hope you are doing it electronically and backing it up!
I just remembered that the professor who sponsored my underwater ROV team last year gave some of the guys a crash course in propulsor design, including the thrust propellors put out. I'll see if I can get him to help.
Craig if you leave what I think you do at the Bottom of your Timmi cup I don't want to know what you have done to your pots and pans lol.
Oy vei! You just can't play nice Curt! *shakes his head* *groans* *streches* *sticks another pin in the Stokomoto doll* Now that that display is over with... Quickly Carl post! Before Curt has another brain fart! I also await the information.
Sorry for the delay but I am waiting for the spread sheet from my friend. Be patient guys I will get it to you. Meanwhile have a corndog.
Drive motor / propeller data of my ships: WWII Scharnhorst, 31 LBS, small gun, 24 sec speed Single drive motor, .125” dia shaft, 550 size. High power version, 1.3 amps no load when powered from 6v SLA Motor draws 8.5 amps in the water with two drag disks. Motor drives a Traxxas gear box #1521R. 28 tooth driven gear (Traxxas #1508 ), 14 tooth pinion. Propeller shaft is 5/32 brass rod. Direct coupled to the 28 tooth gear. Propeller is 2.0” dia 3 blade cast bronze prop. This is the older style prop sold by Dumas that is no longer available. Convoy ship, 8.5 LBS, small gun, 34 sec speed Single drive motor, .125” dia shaft, 540 size. Very low power version, 0.3 amps no load when powered from 6v SLA. Motor is no longer available. Motor draws 1.5 amps in the water with one drag disk. Propeller shaft is 1/8 brass rod. direct drive prop shaft via Dumas dog bones. Propeller is 1.38” dia 2 blade plastic Octura #1435 prop. WWI von der Tann, 17 LBS, small gun, 26 sec speed Dual drive motors, .125” dia shaft, 540 size. low power version, 0.7 amps no load when powered from 6v SLA. Total motor draw is 6.2 amps in the water with two drag disks. Motors drive Traxxas gear boxes #1521R. 28 tooth driven gear (Traxxas #1508 ), 13 tooth pinion. Propeller shaft is 5/32 brass rod. Direct coupled to the 28 tooth gear. Propeller is 1.50” dia 3 blade brazed brass Dumas prop. Right & left hand props. This is the newer style prop sold by Dumas with the cupped blades. WWII HMS Nelson, 25 LBS, big gun, 45 sec speed two drive motors, .125” dia shaft, 540 size. low power version, 0.7 amps no load when powered from 6v SLA. Motors are modified. Added extra windings. 0.3 amps no load when powered from 6v SLA Total motor draw is 2.5 amps in the water with no drag disks. Propeller shafts are 1/8 brass rods. direct drive prop shaft via Dumas dog bones. Propeller is 1.50” dia 3 blade brazed brass Dumas prop. Right & left hand props. This is the newer style prop sold by Dumas with the cupped blades. Mark
