Jump to content

horatio

Members
 View Profile  See their activity

  • Posts

    182

  • Joined

  • Last visited

  • Days Won

    6

 Content Type 

Posts posted by horatio

    Futaba MC112B vintage esc popped

    in General - Electric

    Posted

    To test a MOSFET with a multimeter, first, check for a diode reading between the drain and source with the gate shorted to ground. If the MOSFET is good, there should be a diode reading in one direction only, depending on whether it's an N-channel or P-channel MOSFET. Then, with the gate charged, check for continuity between the drain and source; a good MOSFET will show a low resistance (on state) when the gate is charged. 
     
    Detailed Steps:
    1. 1. Identify the MOSFET type (N-channel or P-channel):
      This is crucial for setting the correct polarity on the multimeter. 
       
    2. 2. Short the Gate to Source:
      This discharges the gate's internal capacitance and ensures the MOSFET is in the off state. 
       
    3. 3. Diode Test (Drain to Source):
      • Set the multimeter to the diode test mode. 
         
      • For an N-channel MOSFET, the red probe should be on the source and the black probe on the drain, and you should see a diode reading (e.g., 0.4V to 0.9V). If you reverse the probes, you should not get a diode reading. 
         
      • For a P-channel MOSFET, the red probe should be on the drain and the black probe on the source, and you should see a diode reading. Reversing the probes should not give a reading. 
         
    4. 4. Gate Charge and Continuity Test:
      • Briefly touch the red probe to the gate, then quickly move it to the drain (while the black probe is on the source). 
         
      • You should see a low resistance or continuity between the drain and source, indicating the MOSFET is in the on state. 
         
    5. 5. Gate Shorting (Off State):
      • Short the gate to the source again to discharge it and return the MOSFET to the off state. 
         
      • Repeat the diode test from step 3 to verify that the MOSFET returns to its initial off state. 
         
    What to Look For:
    • Good MOSFET:
      Should show a diode reading in one direction only (Drain to Source for N-channel, Source to Drain for P-channel) with the gate shorted. With the gate charged, it should show continuity between the drain and source (on state). 
       
    • Defective MOSFET:
      If you get a reading in both directions (Drain to Source and Source to Drain) with the gate shorted, or if there is no continuity between the drain and source with the gate charged, the MOSFET is likely defective. 
       
    • Note:
      Some MOSFETs have a body diode that can affect the readings, so be aware of the MOSFET's type and datasheet. 
    • Like 1

    Futaba MC112B vintage esc popped

    in General - Electric

    Posted

    Was there anything glued onto those blue caps - or are their insides now on the outside? 😅

     

    If it is the caps that have gone, you could replace them with quality Panasonic ones for a very modest sum - less than £15.

     

    If it isn't the Caps (they always smell when they go) it could be one of the actual MOSFETs.

     

    Still repairable either way, but if you're not competent at soldering, it would be worth taking it to an electronic repair place. Be prepared to explain what it's for! 😅

    This old age question!!

    in Large Scale RC's

    Posted

    5 hours ago, Dun2504 said:

    You want a carbon roll cage on that car.

     

    I want one, but I worry that it wouldn't be very forgiving?

     

    The Baja is no slouch - it's nice and light.

     

    Screenshot_20240714-174628.thumb.png.96cc7d7572ecaffa1643965c0c8069a9.pngScreenshot_20240714-174211.thumb.png.f526fc1a59b441a58d16a88f687ea5f1.png

     

    This is on the 16 year old 26cc Fuelie engine on 17/57 gearing. 🤣

    This old age question!!

    in Large Scale RC's

    Posted · Edited by horatio
    Adding a photo

    On 19/11/2023 at 12:52, Dun2504 said:

    Finished building my Modified Rovan Baja with 30DN 38 engine on high speed gearing , to be honest I enjoy it more than my 30DN Buggy , but not as much as my shorty Q with a Rovan 36 fitted.

    piccy.jpg

    metal.jpg

    pic.jpg

    By far - one of the nicest looking Bajas. Great colour coordination!

     

    Do you do interior design by any chance? 😝

     

    In my totally unbiased opinion - it's far prettier than a Marder. 😎Screenshot_20250220-210428.thumb.png.a069669f8dab88faa168b9b2e08edca1.png

    Post up a random picture and keep it clean please

    in The Lounge

    Posted

    Screenshot_20241229-1343372.thumb.png.bb7e41f241d935b8f82b1935bcd21d44.png

    Screenshot taken from a video I took of a 'Black' helicopter. You know - the ones they tell you that don't exist.

     

    Screenshot_20241229-1631102.thumb.png.868eebe4580ac3699e435ecd3b3288ba.png

    The crew were disturbed by a tractor entering the land, so they took off just a few seconds after landing.

     

    They then circled around behind the woods that you can see in the background, below treetop height and headed North.

     

    The Helicopter was a Puma HC2.

    • Like 1

    Post up a random picture and keep it clean please

    in The Lounge

    Posted

    Yeah, the eye for a keyhole is pretty creepy! May as well be a camera I suppose by today's standards. 🫣😅

     

    Walls have ears, beds have bugs, wardrobes have skeletons (although I note the hand had meat on the bone!). What I thought was a salt cellar is more likely a decanter and glass - either way I wouldn't be drinking the water! 🤣

     

    It's just like going abroad. Or an Airbnb. 😝

    • Like 1
    • Haha 1

    What happened to Tenth Technology?

    in General RC

    Posted

    5 minutes ago, wolfie1 said:

    Apex models, i wonder whatever happened to them

    Good question. They were a company I dealt with a lot at one point. 

     

    I only ever had one bad experience from them, but it was a rogue member of staff over the phone. Otherwise, they had been consistently excellent to deal with. At some point in 2018 'poof' - gone. I think the last time I ordered anything from them was back in 2009. Parts for a Jammin X1 CRT. 😎 Great Truggy! 

    Storing lipos outside

    in General - Electric

    Posted

    I think all of the videos force the boxes to fail, it's kinda the point, but I hear you with regards to piling batteries on top of each other - it's exactly like an accident waiting to happen! 😝

     

    In my estimation, a fairly good example of how real world humans put all their eggs in to one basket.

     

    But there are still those who leave lipos lying around in a cardboard box, under the bed. 

     

    Somebody brought round their 8 year old son's RC car with a 4S lipo in the car, the other in the box. All kept in the child's bedroom. The charger - incorrect. A fire waiting to happen. 😬

     

    Ammo boxes will vent all around the lid - even more videos on the virtues of the humble .50 cal ammo cans because they were around first.

     

    Bat boxes vent above the lid. It all depends on how much lithium polymer is burning. Either way - they shouldn't be left in the living space. 

     

    Ultimately, people can pay their money and make their choice. So long as they do, that's the main thing. 

     

    Burying their heads and storing their lipos in a handbag doesn't count. That's the great thing about this thread - people are talking about it. 👍

     

     

    Storing lipos outside

    in General - Electric

    Posted · Edited by horatio
    Magic smoke

    Having experienced a lipo fire indoors, through no fault of my own - on the lipo's first charge - I highly recommend keeping lipos outside, in a metal box, in the naughty corner. Because all lipos are knobheads, waiting to get you while you sleep. 🤡😝

     

    image470.jpg.da0eeaf167a925f93c8b6139a27c76be.jpg

    The heat was so severe, that even on a glass mat, it burnt the table underneath.

    image469.jpg.2ee20618344bc912a8ef0af0e7bc09d1.jpg

    Sadly, a little 6 channel Heli was destroyed on its first ever charge. 

    image471.jpg.2a7931993f74424a12c1a7602b28fda1.jpg

     

    However - nobody died, and I learnt that even tiny, 2S 1000mah lipos can pose a significant risk.

     

    I use .50 Cal ammo boxes. The seal keeps moisture out and if you're worried about an explosion, a small vent hole can be put into seal.

     

    Bat Box XL:

    0008981_bat-safe-xl-silver-lipo-charging-box.thumb.jpeg.1819b937a607ffe2c3ffcdc9196b282e.jpeg

     

    My interest in Bat boxes dwindled following this video:

     

     

    If you have multiple batteries inside a box, you want the box to be made from steel. The bat box is steel, but ☝️ - holy mother of God! 😬

     

    Nobody needs this kind of event happening in their garage, let alone home. So be advised. 

     

    Ideally, lipos should be separated from one another inside your chosen container, preferably with cement board.

     

     

    If you use an ammo box, put holes in the seal to allow it to vent. You don't necessarily need to perforate the box. In fact, in my estimation, it's better not to perforate the box to prevent moisture ingress.

     

    Whatever you choose needs to be somewhere - or on something - that isn't flammable. Ie, a concrete floor, or inside a steel work bench, well away from other flammable things.

     

    PXL_20240615_132130203.thumb.jpg.0466ad5d26ecaaf9ad7ea9812ba97192.jpg

     

    I don't doubt that Bat boxes are safer than lipo bags, but I'll take 5 x .50 cal ammo cans at less than £20 each over a large bat box at £100. Facts!

     

    Screenshot_20241112-224734.thumb.png.92035f9c894142acb22a63a767749f4f.png

     

    Lipos should be balance charged at sensible rates in accordance with the manufacturer's recommendations. They should be stored in storage mode (ie - about 30 - 50% charge) and internal resistance should be checked every few months.

     

    PXL_20241011_153802746_MP.thumb.jpg.11c9d3948cef9e408d596cd6a2e890ab.jpg

     

    Lipos prefer to be stored in a cool, dry environment. Whilst cooler temperatures below 15°C inhibit their discharge performance, this is a temporary artifact and performance improves as the temperature rises.

     

    However over 30°C, battery chemistry degrades and leads to reduced capacity and permanent degradation.

     

    Joshua Bardwell is the world leading authority on FPV drones.

    Here's his take on lipo retirement.

     

    When it's time to retire your battery - take it to a dedicated battery recycling centre - advising them that it's a lipo battery. Make sure they understand what a lipo is. "It's not just an AA battery mate - capeesh?"

     

    Otherwise, this happens:

     

    Ezw8hTiXMAQH84b-1.jpg.d66b5f9fac276e797bc613ea7464e84e.jpg

     

    Somebody disposed of a lipo in a blue recycling bag and this local recycling centre burned for 2 days. I roasted a whole bag of marshmallows. 

     

    After this event, I didn't feel so bad about my burnt helicopter. 🙊

     

    Lipos are an essential part of the hobby, but the risks they pose are very real. Perhaps the most overlooked danger from lipo fire are the fumes. They produce enough deadly fumes to readily kill you.

     

     

    In this instance, the householder makes a hasty retreat with their pet and child. Good move. Spoiler: the E bike didn't make it out. 😝

     

     

    Sadly, in this instance, 6 people where asleep when this lithium ion fire started. 4 died. 😱

     

    RC car enthusiasts generally don't want to hear or accept that our lipos are potentially hazardous, but simply ignoring the risks they pose is not fair to the other people that may live with you, who are likely blissfully unaware of your growing collection of lipos. You owe it to them. To do otherwise is willfully irresponsible and negligent.

     

    Our batteries require safe storage, away from living spaces and away from escape routes. Mitigate the risks and enjoy your hobby. Don't put yourself or your loved ones at unnecessary risk. Oh - and sleep easy. 👍

     

×
×
  • Create New...