RE: Motor and Gearbox Testing
[quote]With one of these: Digital Photo Tachometer [/quote] There good for the cost. I'm designing a small motor dynamometer to get more meaningful torque measurements, but with a load of other stuff using up my time, and sorting out my Dads funeral, don't expect it to happen to soon! Yours Simon M.
Posted on: 6/3/2008 4:17 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7573717

RE: Motor and Gearbox Testing
Interesting results, how did you measure the RPM? Yours Simon M.
Posted on: 6/2/2008 5:05 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7571705

RE: hl tiger running problem
Only thing is though, you have set a trend. Now all the busted / unrepairable / other kids duff castoffs will come your way, to be fixed NOW![:D] Yours Simon M.
Posted on: 5/16/2008 2:30 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7503850

RE: electronics hook up questions.
To get a little technical here, they are white LED's and as such are rated at 20mA. I know that this is a fat lot of use to most users, however it works out at around 3.2v, and yes they are polarity sensitive. On HL they are wired in parallel so you need to double the current required. If you want to connect them up to the battery you can either wire them in series, and add a 39ohm resistor, wire them in parallel and put a 100ohm resistor in series with them. If you want to connect the the TK-RX13# or TK-RX14 5v then you will need to connect them in parallel and put an 81ohm in series. I know that this is a little geeky but you did ask! Yours Simon M. P.S. One method to tell which way to connect an LED up is to look very closely in to the package. One connector is smaller than the other. In the vast majority of cases this is the +. In over 25years of using the things I can only think of one package where this was not the case.
Posted on: 5/16/2008 8:39 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7502779

RE: hl tiger running problem
Don't bin them, I'm sure some one can make a working one from two dead ones. Yours Simon M.
Posted on: 5/16/2008 8:09 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7502694

RE: hl tiger running problem
It does sound like one side has a duff output transistor. With out burning your fingers can yo check to see if any of the black chips on the riser board near the motor plugs are getting hot. Be careful, they can burn! Yours Simon M.
Posted on: 5/15/2008 5:32 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7500410

RE: Comunication problem in HL Tiger I S&S upgraded
Interesting wackywheelz, When I looked at the HL receiver board (TK-YL101) it has a MC3361BP chip on it which is a FM decoder, and the transmitter uses a classic FM oscillator circuit, hence my assumption. Now you have me confused! Yours Simon M.
Posted on: 5/15/2008 11:58 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7499328

TK RX14 Circuit
I've added the TK RX14 Circuit to the FAQ section if any one is interested. Yours Simon M.
Posted on: 5/15/2008 11:52 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7499315

RE: RC Tank F.A.Q.
TK RX14 Circuit Its basically a RX-13# with a MOSFET output stage. This gives ups it to at least 10A, but only 2W. I cannot identify the 'LL6' SMD, if anyone is aware of what it is I'd be grateful. Yours Simon M. Download the attached and dump the .TXT
Posted on: 5/15/2008 11:50 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7499303

RE: Comunication problem in HL Tiger I S&S upgraded
Hi Jeferson, I must admit that I've not tried that experiment. Some time ago I decided that HL crystals are at best weak, and replaced them all for HPI FM ones. They did cost a bit, but then the reliability went up! What I was wondering is if some 'AM' crystals had got in to the mix, and these will definitely NOT work. HL electronics is FM only, and I don't know of an easy way to spot an FM crystal. Yours Simon M. I will try your experiment sometime & report back.
Posted on: 5/15/2008 11:34 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7499264

RE: Comunication problem in HL Tiger I S&S upgraded
When you say [quote]All Heng Long things[/quote] do you mean 1/16 Tanks?
Posted on: 5/15/2008 10:52 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7499131

RE: Comunication problem in HL Tiger I S&S upgraded
Hi Jeferson when you say [quote]from one spare radio and inserted it in a tank[/quote] What is the spare radio is controlling? Is it a working HL, or some other RC model? Yours Simon M.
Posted on: 5/15/2008 9:16 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7498855

RE: Comunication problem in HL Tiger I S&S upgraded
I wonder if its AM crystals instead of FM crystal problem. I don't know of any way to inspect crystals to find out what type it is. Can any one shed some light on this? Yours Simon M
Posted on: 5/14/2008 8:30 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7494383

RE: Comunication problem in HL Tiger I S&S upgraded
I think that somewhere deep in the manual it says [quote]If both headlight flash slowly, it mean that tank lacks power and the batteries need to be replaced.[/quote] Yours Simon M.
Posted on: 5/13/2008 4:09 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7489835

RE: Comunication problem in HL Tiger I S&S upgraded
Hi JIDM Can I ask you to try the following steps 1) Turn tank an TX OFF. 2) wait for 60 seconds 3) Turn Tank on ONLY 4) Do the lights flash? 5) Turn the transmitter ON 6) Do the lights flash? 7) Press ignition 8) Do the lights flash? Can you report back please against steps 4, 6 and 8 Yours Simon M.
Posted on: 5/12/2008 6:03 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7487853

RE: RANGE HAS REDUCED
Hi Pete, 1/8th or 1/16 wavelength is pretty universal for whip aerials. So if memory serves me correctly, the formula is (speed of light)/(radio frequency) = wavelength for 1/16 @ 27Mhz 300e+8 / 27e+6 / 16 = approx 700mm. for 1/16 @ 40Mhz 300e+8 / 40e+6 / 16 = approx 470mm. Don't forget that this is the total length from RX board to tip of antenna. There are components on the RX card to compensate for differing aerial lengths, and these can be easily adjusted (with the correct equipment). Like most things I suppose. Measuring my aerials looks like HL are using 1/32 antenna. Yours Simon M.
Posted on: 5/12/2008 5:40 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7487742

RE: RANGE HAS REDUCED
Hi Pete You said it, you've stuck it inside a metal box. (I bet its a well engineered box). What sort of aerial are you using? Is it the bog standard one, or a loop antenna type? And / Or any pictures please? Yours Simon M.
Posted on: 5/11/2008 6:06 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7483914

RE: Motor and Gearbox Testing
Hi Blitz, Yup your correct, the RX-14 is a rare animal. I've only got one and have yet to reverse engineer it. I've had a few personal issues at this end including a trip to hospital, along with a very dead PC haven't been able to concentrate much else. I hope to be in better shape next week so will restart in earnest Yours Simon M.
Posted on: 5/7/2008 4:48 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7468088

RE: Motor and Gearbox Testing
Hi Jake, I'd love to send you what I've got, but my PC mother board died taking the raid disks with it! At this moment I'm tring to recover the files. Yours Simon M.
Posted on: 5/3/2008 5:10 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7452025

RE: Reciever Boards
If wanting to keep the cost down, I'd suggest HL TK-RX14 s&s setup Yours Simon M
Posted on: 5/2/2008 4:05 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7448604

RE: Motor and Gearbox Testing
Hi Jake, Where did you find the motor manufacturers data? I'd like to check my findings against them. Also I want to see what the final drive shaft torque should be! Yours Simon M.
Posted on: 5/2/2008 4:00 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7448590

RE: Custom Track Vehicle
Hello Brice Arnold. [quote]30-40 lbs. Engine will be a Zenoah 26. Speed will be around 40 mph[/quote] Wow! On a tracked machine, what sort of BHP / torque is required to achieve this performance? If you look at http://www.rctank.jp they have a video of someone riding around in one of there models. Yours Simon M.
Posted on: 5/2/2008 3:52 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7448545

RE: The KING
One of the better tank videos, nice to see you have kept to the 5 sec / clip rule to keep it tight and interesting. Even my eldest managed to watch it with out reaching for his PSP![:D] Yours Simon M.
Posted on: 5/2/2008 2:08 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7448214

RE: RC Channels
I like your thinking Dave[:D] Yours Simon M.
Posted on: 4/30/2008 4:36 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7440465

RE: Heng Long Gearbox's
OK I've got a bit further with this, but as 971wright pointed out it is going to cost. The gears alone for this project, and I hope you are sitting down, is around £220. I hope to work on this price some what, but it will give me a set of gears that is 128:1 and has a 14kg for 15mins / hour service life. Now if only I can make sense of this. Yours Simon M.
Posted on: 4/30/2008 3:56 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7440288

RE: HL crystall replacement
HPI FM crystals work a treat, so can steal from one from your truck. Yours Simon M.
Posted on: 4/30/2008 3:20 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7440132

RE: Hen long speeds
Now wouldn't that be super cool, could also be used to simulate correct recoil action dependent upon which way the canon was facing, or even which side hit from! Yours Simon M
Posted on: 4/30/2008 3:16 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7440118

RE: WOW..Nice Tiger...and Panther
Hi if look here http://www.rctank.jp/machine/tiger-e.htm, this is the 'extra channel feature' i wanted, and if you look here http://www.rctank.jp/machine/tiger-e.htm this is who makes them. I can't take credit for finding these people, as there URL came up on the 'who sell what' link before mr.moderator tokk it away! Yours Simon M.
Posted on: 4/30/2008 6:02 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7438507

RE: Motor and Gearbox Testing
Hi Jake, Sorry for the slow reply, my machine went down soon after I wrote my last piece. [quote]If Torque 0, Amps/Watts also 0 ? [/quote] No if this is so then efficiency of motor would be 100%. (true the motor Must be producing some torque, but this is only what is required to overcome any resistance, air or frictional, and thus unusable, so ignored) For a DC motor and a fixed voltage it works like this Max RPM = No Load = 0Nm 0 RPM = Max Load = Max Torque. Since motor power is a function of torque and RPM it follows that the motor is producing no power at these points, BUT is using power, thus the efficiency is 0. Referring to the link, http://www.mabuchi-motor.co.jp/en_US/technic/t_0201.html , if you click the About Performance Chart link in the left, it explains quite clearly the different bits of the graph. What you have produced in you chart is useful, but I think needs a little more work. I tested my motors out of the gearboxes, as I wanted to remove as many vairabls as possible. Then stepping the voltage up at 0.5v steps to 10v noting with a strobe the RPM. From this I was able to find the motors ‘K’ value, (Volts / RPM). Regards stall current. Again a bit of physics. When a motor is stationary it produces no back EMF, that is to say the source only ‘sees’ the DC resistance of the motor. Thus current can be found using ohms law. And since torque is a function of current, along with a ‘motor factor’, we can deduce what torque can be produced for a given current flow. So I again I measured the pull the motor gave at differing current limits, in 0.5A steps to 3A. I used a simple spring scale attached to the shaft of the motor via steel cable. Measured the diameter of the shaft and calculated is equivalent Nm. This is where the repeatiabity failed, and I ran out of time to make a clutch type Dynamometer, hence not been published. I chose not to included the gearboxes in my testing as I find all of them such poor engineering quality, there results will vary wildly from gearbox to gearbox. Interesting that El-Mod choose to limit the voltage at 5.5v. I would of limited the RPM, especially since they seem to use quite a clever microcontroller setup. Yours Simon M.
Posted on: 4/30/2008 5:51 AM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7438499

RE: Antenna Mod Re-Post
No, in a word. By the way I have seen this type of aerial made using 'ribbon' cable, the sort you find in PC's connecting IDE devices. The trick is to make sure that the cable connects to its neighbour at the far end. eg, the red cable is the start, far end is connected to its neighbour start. Yours Simon M.
Posted on: 4/28/2008 5:29 PM by Author "samarkh" in the forum "RC Tanks"
http://www.rcuniverse.com/forum/fb.asp?m=7431631