RE: Homemade monster servos
Looks like a project I am yet to start, it looks like you are replacing the quad frame with a better chassis, Correct? Seriously don't bother with the H-bridge, use a commercial product like the Baby Bully servo amp I linked to earlier in the thread, saves a lot of heart ache for non electronically minded builders. I would have ended up spending more on components than what the Baby Bully is worth, the H-bridge needs a control circuit that takes the input from the RC receiver and converts it to signals to operate the H-bridge, the H-bridge is only the high current motor switcher. Cheers Nick
Posted on: 5/19/2013 12:56 AM by Author "nick_75au" in the forum "RC Giant Scale Cars"
http://www.rcuniverse.com/forum/fb.asp?m=11515782

RE: Homemade monster servos
Ive been researching the same thing, I had a circuit working well using an Oatly Electronics kit which is no longer made unfortunatly, I got everything working using some power seat motors, they even had the pot intergrated with the motor so no messy extra arms to drive the pot, only thing is the final test I reverse polaritied....... and [&o] the circuit Vantec now make a plug and play solution now for $79.95 US http://www.vantec.com/servocat.html Worth a shot for those not electronically inclined Nick
Posted on: 12/7/2011 1:45 AM by Author "nick_75au" in the forum "RC Giant Scale Cars"
http://www.rcuniverse.com/forum/fb.asp?m=10847491

RE: Lets hear about your Thunder Tiger Neptune SB-1.
Pool isn't salt water is it? If it is then reception will be very poor to nil when submerged even slightly Nick
Posted on: 9/28/2011 12:12 AM by Author "nick_75au" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=10737921

RE: electric
[quote]ORIGINAL: proanti1 Most of Tesla's inventions were junk and unfeasible. His ''wireless'' electricity? A gimmick. I hate our dependance on oil as much as the next person, but oil is cheap. The government is not ''snuffing out'' inventions in favor of the stuff. There is not some super secret high efficiency engine that government has covered up. Stop reading between the lines. Our schools and universities are far more powerful than oil companies. Do your homework, but dont read too far into it. [/quote] Wireless electricity transfer happens every day, reading the forum on a wireless router, electricity transferred wirelessly[:)] http://en.wikipedia.org/wiki/Wireless_energy_transfer Nick
Posted on: 6/16/2011 2:37 AM by Author "nick_75au" in the forum "RC Car General Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=10576588

RE: electric
[quote]It actually is just a theory to have perpetual motion you have to have a frictionless setup and as we all know friction it everywhere ESP when creating electricity so until some on can get rid of friction it's is just a theory [/quote] [quote] im not trying to get perpetual motion just an extra boost of power and perpetual motion isnt a complete theroy its just incredibly hard to get right [/quote] All you people talking about perpetual motion as a theory theory don't have a clue. A theory is based on scientific evidence that can be repeated and peer reviewed. It has higher truth than facts, and is where calling something just a theory is where a lot of people (Religion) get it wrong when trying to state a case. Perpetual motion is NOT a Theory or even a Hypothesis Anyway the answer to the OPs question is a series/parallel switch, 2 batteries of the same voltage and capacity wired through a switch that can swap the batteries from parallel to series connection Nick
Posted on: 6/16/2011 2:28 AM by Author "nick_75au" in the forum "RC Car General Discussions"
http://www.rcuniverse.com/forum/fb.asp?m=10576585

RE: Lets hear about your Thunder Tiger Neptune SB-1.
SB_1 is my first sub, I think its fantastic, I purchased mine second hand for $400 (I saw it in a LHS for $799), so that's a good price new. My camera experience is minimal but I fitted a helmet cam and a wired "FPV" First Person View cheap B&W board camera. Unfortunately the water hasn't played well and every time I go to a lake its murky, The other problem is weed, I got my sub tangled in about 5Kgs of weed, I was lucky to get it back heaving on the very thin Co-ax (3mm) I brought the SMA co-ax connectors online for a fraction of the price of the Thunder Tiger parts, the camera just uses a 3.5 mm stereo jack to plug into a small LCD monitor. If at all possible try and make the cable slightly buoyant, as mine was not it gets tangled easily on bottom features. Mine came with a basic 4 ch transmitter as part of the package. I havn't had any control issues re dive planes, the only modification I made was a larger brass prop that fits closer to the shroud, just a 55 mm with the outside of the blades sanded off with a disk sander. You will need to find a monitor with built in recording, i dont know of any wired cameras that have self contained recording capability, my plan was to eventualy stream to a laptop via usb tv in device but I haven't got there yet. Cheers Nick
Posted on: 10/28/2010 2:57 AM by Author "nick_75au" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=10099345

RE: esc selection help
With Apologies to the OP for a minor hijack [quote]ORIGINAL: NobodyFamous  Does this mean brushed motors (1 phase) and brushless (3 phase) because I have some monster 800 brushed motors I'd like to use (maybe even as a power wheel upgrade) but no one makes a decent brushed ESC with big amp output. [/quote] Hi I have a power wheels as well, I have 2, 700 motors on 24 volts and Ive driven both on one of these with 2 kids on board[:D], it will handle 4 (I've done it in a big model boat) http://www.robotcombat.com/products/IFI-V885.html Nick
Posted on: 10/22/2010 6:48 PM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10087209

RE: 46
A 65 mm prop is a big load, as rpm increases amps go up at an exponential rate, Ive got a little pancake brushless that is quite happy to spin a 65 mm prop at 3500 rpm (at 6 volts) if I double the volts to the same set up the motor draws double the current, but the power goes up 4 times, this makes that particular motor very unhappy. To spin a 65mm prop at 10K rpm is going to draw around 40 amps regardless of powerplant, the MFA motor is not going to spin the prop at 10K, maybe 60-75% of that so 7500 RPM. I would consider dropping the prop size, 50 mm or so is big enough, a low KV 42 series brush-less would easily drive that prop or a 3:1 -4:1 geared 700 series brushed motor on 3 cell Lipo or 10 cell Nimh. If you decide more performance is required then you can increase the cell count, but run times will reduce. Look at ACTion electronics http://www.action-electronics.co.uk/wd.php Lots of single twin and triple set-up diagrams Brushless , you will need 2 ESCs if you run 2 motors, brushed motors can get away with one ESC but you loose the prop steering capability Hope this helps Nick
Posted on: 10/22/2010 4:14 AM by Author "nick_75au" in the forum "RC Boats General Discussion"
http://www.rcuniverse.com/forum/fb.asp?m=10085626

RE: sealing holes without useing rubber boot
Some of the guys over hear are using the disposable ear defenders (little foam plugs) push the rod through the centre and then squash the plug into the exit hole. Nick
Posted on: 10/2/2010 11:22 PM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=10043685

RE: What is fiberglass composite??
Generally it just means the completed lay-up, its a composite of resin and fibreglass fibres .Fibreglass refers to the fibres used, most people just shorten the name to fiberglass. Nick
Posted on: 8/28/2010 12:21 AM by Author "nick_75au" in the forum "RC Boats General Discussion"
http://www.rcuniverse.com/forum/fb.asp?m=9964693

RE: Henry martin- Nooh.
Woah, sorry to hear this, I went to see Henry down at his lake when I thinking about getting a gas boat running again, great guy, entertaining day. Condolences to his family and friends. Nick
Posted on: 8/20/2010 5:41 PM by Author "nick_75au" in the forum "RC Boats General Discussion"
http://www.rcuniverse.com/forum/fb.asp?m=9948153

RE: Bondo glass spraying
The proper thinner for polyester based resins is styrene monomer, acetone can be used at a pinch. Nick
Posted on: 8/20/2010 12:41 AM by Author "nick_75au" in the forum "RC Boats General Discussion"
http://www.rcuniverse.com/forum/fb.asp?m=9946668

RE: Lets hear about your Thunder Tiger Neptune SB-1.
My apologies, it was 1800 RPM out of the water and 1500 in the water, its been a while since I ran the boat, Is that the hole you were looking for? I would like to know Your kidding about the 10 amps aren't you, we have the smallest Minn Kota trolling motor and it draws 44 amps at full throttle, obviously less at part throttle. The motor I have is the 24 volt version, the 12 volt version has the higher amp draw, in fact its around double for the same power output which is basic Ohms Law. Nick
Posted on: 8/9/2010 3:25 AM by Author "nick_75au" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9920373

RE: Lets hear about your Thunder Tiger Neptune SB-1.
Its 2500 RPM in the water actually its not much more out of the water, Its Direct Drive, 4 blades, A Raboesch type 1, the motor is a Johnson WPS 5.2water pump motor designed for 24 volts, its rated current in its original application is 5 amps WPS 5.2 Pressure Flow Amp. draw 12V 24V 3.9 A 1.6 A 4.9 A 2.1 A 6 A 2.5 A 7.1 A 3.1 A 8 A 3.6 A 9.2 A 4.1 A 10.3 A 4.7 A 11.2 A 5.1 A Fuse required 15A 8A Data from Johnson website listing current draw at various (pressures removed as not relevant to discussion) Nick
Posted on: 8/6/2010 11:22 PM by Author "nick_75au" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9916069

RE: Johnson HC970
What size props and do you know the RPM of the motors? They will run fine on either voltage, its the prop and how fast you want to spin it that affects current draw. Nick
Posted on: 8/6/2010 10:46 PM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9916022

RE: Lets hear about your Thunder Tiger Neptune SB-1.
[quote]That's over SIX AMPS current draw! It's no wonder that you've resorted to water cooling. Too much load on the motor.[/quote] On a 3 1/2" prop that's quite reasonable, what RPM is it turning, and what volts, Drill motors can handle 30 amps for short periods in a drill and easily sustain 10-15 for a full charge. Ive got a 4 inch prop in a boat that draws 5 amps on 24 volts at 2500 RPM, a Motor and gearbox set up for same RPM and run it on 12 volts it draws 10 amps no matter what motor I use. My SB-1 runs fine on a 55 mm prop cu8t down to fit inside the shroud and no other changes, I did replace the ESC because the stock ESC did not like 12 volts and the BEC kept cutting out. Nick
Posted on: 8/6/2010 10:36 PM by Author "nick_75au" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9916008

RE: Scratch build help needed, please
For a displacement boat 4 Mph might be somewhat optimistic, I run a Springer (truck-able tow-boat, a square box essentially) which weighs 8Lbs and a 40 mm prop, I gps'ed it at 2.9 Kph. To get a 60 mm prop working you need about 3000-5000 RPM under load so you either need a largish designed for this RPM at 6 volts or a somewhat smaller but faster motor with gear reduction. 60 mm prop is too big to be direct driven by most hobby brushed motors, A graupner speed 720 torque will work but at 6 volt it may not have enough rpm. A higher volt battery with the correct setup will have lower amps than a 6 volt setup and still have the same or better power As long as the prop is far enough under the water that it doesn't suck air then its deep enough. Nick
Posted on: 7/1/2010 7:36 AM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=9837953

RE: 85 ft Harbor Tug/Angels Gate
What about a bigger gear reduction, I know a big coast guard Comanche that uses a 700 geared 11:1, turns at 2500 RPM and spins a 100 mm prop , no cooling and very low current draw, uses a 15 amp Electronize speed control. They cost about $120 Au dollars, there is an 11:1, 12:1 and 16:1 ratio , 16:1 at 24 volts spins at 1750 RPM. The company that sells these does ship to the US. If your interested Ill send you the contact details. Nick
Posted on: 7/1/2010 5:04 AM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9837872

RE: Help - New to brushless
Definitely a FE type set-up, Ill leave it for the FE guys to help with the setup, there are quite a few of these NQD conversions done a search through these and RC groups will reveal what others have achieved. Nick
Posted on: 6/25/2010 8:00 AM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=9825853

RE: Help - New to brushless
Im not an FE guy but they do run at 30-35000 RPM on surface drive, If your boat is not surface drive I would drop that figure down somewhat. Your figures are spot on. Some more details of the boat would help in sorting out a good set-up. Props would be around the 35-45mm size, but some experimenting with the inexpensive plastic carbon props will help to find best one. Nick
Posted on: 6/25/2010 3:51 AM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=9825730

RE: Help - New to brushless
Kv is RPM per volt, so a 1000 Kv motor will spin at 1000 RPM at 1 volt, 12000 Rpm at 12 volt, in general higher Kv means more power hungry the motor is as well. A rough guide ~28mm diameter in or outrunner is fairly close to equivalent in power, a ~36 mm will be a better choice as it will run cooler. You can see in the table the Watts (power each motor can handle) http://www.alibaba.com/product-gs/217697595/DC_Permanent_Magnet_Motor_RS_750SH_.html link has some specs on 750 motors top one has a Kv of 415 bottom one has Kv of 1250 so that gives you an equivalent to look for. you have a couple of ways top approach the selection of a motor as well, you could get a lower Kv motor and feed it with lots of voltage ie 2 to 3 8.4 volt batteries in series which is efficient. or high Kv which will need a number of batteries in parallel to give reasonable runtime. Nick
Posted on: 6/25/2010 1:53 AM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=9825641

RE: Springer Tug Build!!!
Hi, Yours looks a lot like my Springer, the classic truck-able towboat Here's the New website for us, just noticed Umi refering to us[:D] http://logancity-marinemodellers.110mb.com/html/home.html There a few other clubs dotted around Brisbane http://triple-s.org.au/ on the north side is a great club as well Cheers Nick
Posted on: 6/22/2010 7:27 AM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9818999

RE: Need help with motors and ESC for a big boat
3- 4 inch , a guy at our club runs two 2 inch geared up slightly on one blower. 3 blade will draw more than 2 blade but give more thrust. Nick
Posted on: 6/20/2010 1:00 AM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9814681

RE: Need help with motors and ESC for a big boat
Blower motors are very good on power, in a car they draw about 5-10 amps, they are usually used in boats with largish batteries will give long runtimes, in saying that its the prop and the RPM that you want to spin it at that determines the current drawn. Nick
Posted on: 6/19/2010 11:36 PM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9814564

RE: Need help with motors and ESC for a big boat
Hi, Straight propshaft will be fine chose one with a M5 thread, this will give you a wide range of brass props to try, you may be limited in prop diameter by the hull For a brushless setup on 12 volts a maximum of 400Kv motor I reckon. http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=5204&Product_Name=TURNIGY_50-65D_270kv_Outrunner_%28eq:_4030AXi%29 will work on 12 volts and up 80 MM props go lower Kv if you use a larger prop. We have a supplier here in Australia that specialises in geared 700 motors, Im not sure about US suppliers , on further reflection a 6:1 reduction is probably closer to the mark, If you can fit a 100 mm prop a 14.4 volt cordless drill and gearbox will work well. Nick
Posted on: 6/18/2010 12:26 AM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9810576

RE: Need help with motors and ESC for a big boat
There are a few options available, brushed motor relatively small say 700 geared down about 10:1( a recycled cordless drill works well ) or large low speed motor such as a blower motor from a car. The another option is a brushless setup, a very low Kv motor direct drive. all of these options are going to have approximately the same runtime for X rpm of the prop, the slower the prop speed the lower the current(higher runtime). Do you know the size of the prop you are going to use? this will help in getting a better idea of setups. Nick
Posted on: 6/17/2010 6:46 AM by Author "nick_75au" in the forum "RC Scale Boating"
http://www.rcuniverse.com/forum/fb.asp?m=9808593

RE: electric conversion kits
What they do is stack the FET boards, its still only one driver board, the 2 ESC idea will probably not work as they may get out of sync. Nick
Posted on: 2/7/2010 4:28 AM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=9483643

RE: electric conversion kits
Little screamers have come up with a big water cooled out-runner that appears to fit the bill http://www.littlescreamers.com/id57.html Don't have one but crunched numbers on it and it will do anything from sport to racing competitively with Gas Its not on the page but has intro price of $149.99 not sure for how long, $179.99 RRP There is a posting on this forum about them. Nick
Posted on: 2/7/2010 2:55 AM by Author "nick_75au" in the forum "Speed - Electric"
http://www.rcuniverse.com/forum/fb.asp?m=9483555

RE: Problem with the TT neptune
I found with mine (exact same problem) its the third fault, low RX battery, the stock ESC was the problem, Its designed for 7.2-8.4 volts, while it works ok on the Higher voltage of the gel Cell the BEC does not. There are 2 solutions, disable the BEC by removing the red wire from the ESC plug and run a separate receiver battery or change the ESC, which is what I did, I used a M-tronics Viper 15 and have not had a problem since. I don't use the stock charger at all. (I have a nice I-charger 208B) Nick
Posted on: 2/7/2010 2:46 AM by Author "nick_75au" in the forum "RC Submarines"
http://www.rcuniverse.com/forum/fb.asp?m=9483548

RE: OS 25 powered Minikaze
From the ashes of the minikaze project this has arisen, something a little more conventional, brushless powered so i can run at our lake[youtube]http://www.youtube.com/watch?v=OcoDsSOjML4[/youtube] Regards Nick
Posted on: 1/10/2010 1:09 AM by Author "nick_75au" in the forum "RC Airboats"
http://www.rcuniverse.com/forum/fb.asp?m=9402951