Well, now it is time to kick off the Baden's build. Today was productive, I made the rudder servo mount and rudder post alignment critter (the mount does dual duty) and I made the belt box. anyways, I can't speak highly enough of the quality of Stephen's hulls (Strike Models). A nice thick (but not too thick) fiberglass layup. First up are hull pictures, followed by pictures of the servo mount, and finally the pictures of the belt drive mount. anyways, pictures! .
Yeah he does a nice job.. And has promised to show me once I finally have my Cnc mill out of the shipping box it came in. I hate when life gets in the way.
Greg, What speed control did you find for the brushless, that runs both directions, and where did you get it at? I was thinking about trying one in my next ship, but have not had much luck finding one. Thanks
Well, there are two options. Justin has one from Mtroniks that he is going to use in the Tirpitz, but it has not seen any real testing. My ESC is a castle creations Mamba series , similar to this : www.castlecreations.com/products/sidewinder_micro.html that I had to make my own waterproof box for. If the Mtroniks one works as advertised, particularly on current limiting, that will probably be the better ESC, however the mamba has worked for years for me (I even burned up the onboard BEC by overloading it and it still runs like a champ). The big thing I like about the mamba's is with the interface cable, you can run the castle creations software on your computer and set just about anything you would want to set, which makes it easy to get going and set the brake & reverse as one desires it.
thanks Mikey! Alright Folks , a question in need of opinions: For the new one unit pump I am making based on the design of my half unit pump, I have two different options for motors. Unfortunatly, due to the utter stupidity of the folks that build both classes of motors, the mounting patterns for the motors and the shaft sizes are different. That means that the two motors are not interchangable. If it was only the shaft, I could readily fabricate a suitable replacement that matched the sizes, but with both mount and shaft different, I really have to choose one to design and build the pump around, and hence the pump voltage of the ship... both motors should happily run in the design range of the pump impeller of ~13000rpm if run on the right voltage source. Both pumps have same material requirement. I would like to hear opinions on either direction, as I can not see a truly overreaching reason to pick one over the other. I currently lean towards the slower/smaller motor, but for no reason of any substance. Even the extra tooling needed isn't a big deal as it is getting time to replace a bunch of my cutting tools anyways. the picture shows the 1/2 unit pump on the left, the heli motor in the middle, and the plane motor to the right. Basically, I have to The specs and my notes are as follows: Option A: (call it the 6V ship power option, middle motor in the picture) 3500RPM/volt nominal (free RPM of ~21000) Idle current: 1.6A Max Continuous Current 19A Shaft size: 3mm, , 17mm spaced M3 mounting holes, 16mm spaced M2.5 holes Bonuses: 6V primary power for entire ship, 12V suppliment still required for solenoids. More powerful, higher speed allows overcoming losses by cranking up speed. Could use onboard ESC's bec to power servos/reciever/ etc. Negatives: Need additional tooling I don't have to fabricate impeller for 3mm shaft (probably 30$ worth of cutting tools, give or take). Onboard esc's bec may (probably is) insufficient. Option B: (call it the 12V pump, 6V propulsion, right motor in the picture) 1360RPM/volt nominal (free RPM of ~16000) Idle current: 1.0A Max Continuous Current 12A Shaft size: 1/8 in, , 97mm spaced M3 mounting holes, 16mm spaced M3 mounting holes Bonuses: No tertiary 12V supply needed for cannons. Tertiary 4.8V supply almost certainly needed for servo's & RX. Motor top end closer to design point of pump, slower top end speed, not as much overage available on design point of pump. I have basically all the tooling needed to fabricate this pump now. Negatives: Less overage available as far as speed is concerned. No BEC as a viable option, as the bec's are typically linear voltage converters, 12V to 5V tends to get awfully hot if not carefully cooled and can let out the magic smoke.
I like the smaller slower less voltage motor. In a Baden, it would be nice to be able to keep it all 6 volts. There isn't a lot of room for extra power systems and more volts do equal more power drain (usually) and heat. A pump would be running a lot.
Unfortunately, those two are mutually exclusive. the smaller, lower powered motor needs 12V to get to the required RPM... I do like the idea of all 6V with a small boost regulator or battery to run 12V solenoids.... I am still just not sure the best way to go.
I have a baden and in it is the BC pump housing with a Traxxas Stinger motor (specs online). I was running fine at the last battle with full pump stream and what turned out to be 37 belows without for 15-20 minutes with no sign of settling. In my ship the recommended strategy is that my pump needs to keep me afloat long enough to empty my magazines then sink or go on '5'. If I am on the water after very long after that I am racking up fast gun damage points that can easily provide more points than a sink. In this case I want the best motor I can get to push the water out fast as I dont have much hull volume and need to keep what I do have - empty. It already sits so low in the water I call it a surfboard. I guess some of it might be affected by how heavy you build the ship. My ship runs right at max weight, largely due to the way the ship was constructed initially (its used) and I dont want to completely dissamble it (subdecks, shafts, etc.).
Well, thanks for the advice, The moment of decision has not yet arrived, but I have finished designing the complex parts of the impeller as well as the complex parts of the pump housing volute. now I just have to tweak them a bit to make them manufacturable on my equipment. I need to go order some 303 stainless steel for the impeller, I have plenty of plastic for the housing. I also plan on picking up some 6061 just in case 303 stainless machining does not go well.
Greg, not to hijack the thread (great by the way), I just got a mini mill (Micro Mark) and am looking to get cuttters, setup stuff. Any advice (I know about little machine shop), was looking at their basic setup for 300.00 Thanks, Lou
I would highly recommend, prior to buying tooling, that you get yourself a dial test indicator, magnetic base, and a ground hardened shaft that can be chucked into the spindle, along with some number 2 way oil. Use those to set up the mill and measure the backlash & alignment on the axes and the runout on the spindle. The reason I say to do this is because your runout has a large effect on tool life, surface finish, and the precision of your cuts. backlash is not as problematic on a manual machine as CNC unless you don't know what it is, then it can be awful difficult to know exactly how many turns to make on the dials for certain operations. This will also tell you what you need to go in and adjust (if it is adjustable) http://www.mmsonline.com/articles/the-real-cost-of-runout.aspx After that, before buying tooling, figure out what you are going to be making, then how you will make it. That will tell you the tooling you need. I still have a vice that I have never, ever used, that I bought because everyone said "you will use this vice a lot".
A friend of mine made these on his plasma table as a test. the table is new and still needs a little tweaking so the holes are circular, but I can fix that on the mill rather readily, I suspect.
they weigh about the same as the same footprint cut from 1/4" thick plywood, not including the waterproofing sealant weight.
