Mad Ax

Ever have those days..?

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I managed to save up a few nights off recently and had a long run of 3 nights in a row to do whatever I wanted.  That's something to cherish when you have a young family :o 

Last night I figured I'd spend some time on my 2019 Revival entry, a re-release Fox.  I built it a few weeks back before I had all the electronics, but I thought I'd at least get the chassis together and decide on a colour scheme while I saved up the cash for the motor, speedo and servo.

I've hankered after a Fox since the early 90s, when I was given a box of junk including a Fox body, but no other Fox parts.  I could only dream about what the rest of the car was like.  I suppose it's a bit like meeting your heroes.  I attacked that chassis for nearly two hours before I got the ESC, servo and receiver fitted.  I don't think it's ever taken so long to do such a simple job.  I sure hope I don't have to replace a servo or receiver on race day...

The steering servo wasn't too bad a job, but there's not a lot of space inside so I cut down the lead.  It would have been nice to shorten the ESC leads also, but I haven't decided for sure that I'll stick with that system.  A Probe WP and a Super Stock BZ might be just right, but then again I might prefer a budget mid-power brushless setup for racing.  So there's a mess of wires under that plastic cover.

Then there's the switch hassle. The Probe WP doesn't have a conventional size switch, which is always annoying when fitting into Tamiya chassis.  But on the Fox it's even worse, because the switch lead isn't long enough to reach the stock switch location.  I ended up drilling a new switch location at the side of the chassis.  Taking a drill to my never-used Fox chassis - that hurt a bit.  I'm not even sure I'm going to stick with that ESC, but you can't even test run the car without reassembling everything.

I had to make up an extension cable for the receiver aux channel so that I can mount my transponder outside the tub.  I'll be racing two cars over the weekend and don't want to have to strip the car down to its base components to swap the transponder out.

And after all that I still couldn't test it.  The motor and ESC leads aren't long enough to meet in the middle.  I'll have to get some more motor wire as I'm all out.

 

Figuring things couldn't possibly go as badly as they did last night, today I decided I was going to fix up my Budget Bruiser for the G6 scale trial at the end of the month.  I needed to fit new XT60 connectors for the 3S LiPos that I acquired recently, modify the home-made battery tray to accept said LiPos, replace the Turnigy receiver switch that lets me turn the lights on and off from the handset, and generally tidy up all the wiring and waterproof it as well as possible.  I also had to replace the Maverick motor, which seized up solid last time out, although I'd already got it mounted in the chassis and just had to change the motor plugs.  That should have been a fairly simple mission for a Friday evening.

Except I couldn't find my replacement receiver switch that I bought off ebay just a week ago.  Took me best part of an hour of turning the workshop over and tidying the bench before I found it, right where I had thought it would be, and was sure I'd already looked 3 times.

Switch found, it should have been a simple case of hooking it up and testing it.  Except it didn't work.  Zip, zilch, nada.  It might have cost less than £10 but to arrive DOA isn't a great start.  A shame too, as it is a powered switch, so requires no additional wiring to run LEDs.  The old broken Turnigy unit which only acts as a switch in an unpowered wire, so it needs to be wired into the power system, making for a slightly annoying amount of extra wiring under an already cramped scale rig.  Especially one that will get fully submerged in two weeks time.

So I set to trying to fix the Turnigy switch instead.  It's a tiny PCB wrapped in plastic, and I figured it had probably got something in it when it last went out in very heavy rain.  It had previously survived being fully submerged but I guess there's only so much a piece of circuitry can take...  Well I did find some dirt under the plastic, but no amount of cleaning would fix it.  I tried tracing pins with the multimeter but to no avail - it's fully on all the time and can't be made to work as a switch at all.  Oh wells...

On that note - and having spent nearly 2 hours playing with electronics and being no closer to finishing than when I started - I figured I'd give up and do something else for the night, so I turned all the lights off and washed my hands.  Almost on a whim I decided I'd hook the new receiver switch into a servo channel to see if I could make it to anything at all, and guess what?  It only went and worked.

So it seems that the cheap receiver switches from ebay (or at least the one I have) don't actually work at 100% deflection.  I had to turn my EP down to 70% on the toggle switch to get it to operate.

So - there you have it.  My rig is still in a pile of bits with all its wires hanging out on the workbench, but at least a) the workbench is tidy now and 2) I have all the bits I need to put it back together again.

 

Now let's hope I get another few clear evenings before the G6 to get it all back in one piece...

 

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10 hours ago, Mad Ax said:

I attacked that chassis for nearly two hours before I got the ESC, servo and receiver fitted.  I don't think it's ever taken so long to do such a simple job.

Yep, me neither! 

I kept it brushed, with a 1060 esc, but ended up unsoldering the motor wires off the silver can, and soldering them onto the firebolt. The esc is switched on permanently, I just couldn't be bothered mounting it somewhere accessible.

PT wise, i got fed up swapping it from my 2wd to 4wd, and that was easy to get to! I've bought another from MRT, as they where doing a promotion on Facebook, (they've since done a buy one, get one half price, if someone else you know wanted one), and got a cloned number (both transponders have the same number). You'd need to check with the track as to check if the MRT transponders work though.

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Well I managed to spend some time early yesterday morning and during toddler's nap yesterday afternoon getting the Budget Bruiser up to spec.  All the wiring tidied, shorter cables made, motor soldered.  I sure hope I don't break any important electrics at the event though, as that Bruiser is a really tight rig to work on.

I even got the cheap ebay remote switch working, although it stopped working once I fitted the 3S battery.  The Crawler ESC is configured to provide 7.4v BEC, but I discovered that under 2S they rarely manage 6v.  I wondered if 7.4V had killed it outright, but with a bit of testing on a servo channel it came back to life, this time only at 50% travel.  So I reset my switch EP and went for a test drive.

That's when it started turning on and off more or less when it felt like it.  Eventually the polarity seemed to reverse, so now it's switched on when the switch is in the off position and off when it's in the on position.

The mind boggles.  It's possible that I'll fit an extra servo extension lead from a spare radio channel so I can plug the lights in permanently on for the night crawl.  I might even have a radio switch here somewhere so I can turn them on manually like I do with my SCX10.

This is very much one of those "meh" moments, I think... :p 

Still - wife and child are going out today, so I'm charging up some lipos now to take a few of my favourite toys out to the fields alone.  Give the Budget Bruiser and SCX10 a pre-run, at least, maybe the Fox too if the wire I found yesterday is long enough for the motor :)

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yeah it’s PITA how servo travel is differently defined :(

BiTD full servo travel was 100% and your fancy TX with EPA dual would reduce that accordingly 

then computer TXes appeared and some smartalec bogging decides to program “100%” travel as default/normal (when it’s only 50-70% of real full travel) then confuse matters by allowing EPA of “200%” :blink:

Not just those pico switches but often some ESCs won’t accept full 100% travel when programming. 

Old TXes without EPA I’ve had to make physical throw limiters to get them accepted by ESCs :( 

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Well the dilemmas continued, when I got the motor connected in the Fox and then discovered the steering servo was real slow.  I mean real slow.  It was a brand new Alturn high speed servo, and while they're not as fast or precise as a Savox they're not bad for the budget, IMO.  I use them in almost everything I have.

So I had to strip the front end down again to work out what was wrong with it.  I'm guessing it was the foam pad that goes over the servo aperture, interfering with the servo operation.  Everything was freer once I took the horn off and relocated it, although it still doesn't seem as fast as other servos.  Oh well, it works for now.

On a positive note, I took a bunch of cars out to a local gravel road while the sun was shining.  The Fox ran well enough until the brushes died in the Super Stock BZ, but that was fine because I knew they were beyond good and had a spare set with me.  So that's one very fast Fox ready for racing.  Just need to get some new pinions.

The Budget Bruiser ran well enough although the terrain was all wrong for testing it out properly.  The lights continued to do whatever they fancied.  I need a second option for the night crawl - don't want to be stranded mid-trail with no lights.  But that's easy - now I have tools to make my own servo leads I can just make an extension for it off a spare channel.

My King Blackfoot ran like a complete fool as usual - it's an epicly entertaining truck to drive - but my new favourite runner is the G6-01 Truck of Many Wheels, which with a Turnigy Trackstar Turbo combo has just enough speed to be fun without being totally crazy.  For a rig that has friction shocks and plastic steering arms it runs straight and true on bumpy ground.  I was running it up and down a deep 4x4 wheel rut that wasn't much wider than the trucks' tyre width, but it kept on track and handled everything I threw at it.  In fact it only went upside down once.  I absolutely love that truck.

:)

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Been there.... When things don't quite to plan and problems and issues end up taking waaaaaay longer than expected to solve. My simple quick swap of a prop shaft on one car ended up as a 6 hour strip down and rebuild of 3 cars just to eliminate one issue I had.

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Can you say Gulf?

Dilemma comes in two colors, light blue and orange:lol::lol::lol:

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Honestly, the "worst" day tinkering at my workbench is still better than most boring days at work...

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Well I had another odd one this morning.

I woke up early, and the sun was shining, so at 5:30 am I headed up to the workshop to make some more progress on a super-quick project that I started Tuesday night.  (I'm calling it Project Fortnite, on the basis that it started life as a pile of parts that haven't seen light in 10+ years and mostly haven't ever been used except for the odd test-run around the old flat, and I want it finished in time for the UK G6 in just over a week's time).

So I needed to make up some new 4-links.  I use M4 allthread from B&Q and previously used Junfac plastic rod ends until Traxxas became a cheaper and more robust alternative.  Well, this particular bunch of parts already included 6 links made up from Junfac ends, all I had to do was cut the allthread to the right length and re-fit the ends.  However for the final 2 links I needed 4 new rod ends, and I didn't have any Junfac ends left.  I went to my trusty stash of Traxxas ends, counted out 4, and made up one link.  I remarked to myself how much better the Traxxas ends were, because they felt so much stiffer going into the plastic.  Much less chance of pulling out, I thought.

When I came to make the second link, the allthread went straight into the rod end.  I figured it was one bad part in a pack of 40 so I tossed it aside and tried another. Nope, that one's loose too.  And another, and another, and...  Wait, none of them fit!

I got an M4 nut out of my nut stash to check for definite sure that it was an M4 thread, and yep, it is.  OK, the nut is a little bit loose, but it's the right thread.  A UK high street stockist like B&Q wouldn't have anything but metric on the shelf and I've never bought any allthread from elsewhere.  The only other allthread I have is stainless M3 which in the UK is an internet special order item unless you have a handy local specialist steel stockist.

I tried a few other M4 threads that I had lying around and, no, none of them fit snugly in the Traxxas ends.  They're all loose.  The only ones that aren't are the two that I picked out blindly to make up the first link.

What are the chances?

I'm assuming that those two, by pure luck, happen to have come out of the factory slightly tighter than the others, and that particular bit of allthread (from a much older batch) is a slightly fatter cut, but otherwise I have a tub full of Traxxas ends that are useless on metric allthread.  I can only guess that the Traxxas ends are actually made for an imperial thread.

I also incorrectly remembered my old Junfac ends as RC4WD ends, so about 10 minutes ago I placed an order for 40 RC4WD rod ends.  Now what's the bet they'll be the exact same ID as the Traxxas ones, and won't fit any of my allthread either..?

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Experience a few instances of this myself recently.

First, I'd bought a second hand ESC and hadn't noticed until it arrived that the motor wires had been cut rather short. "No matter" I thought, "I'll just unsolder those and solder some longer one sin their place". Out with the soldering kit, strip the heat shrink that was covering the connection posts on the ESC - just to confirm that I could actually unsolder them. All good to go I look for some blue, orange and yellow 14awg wire - but I haven't got any. Could have sworn that I had but ended up having to pack everything away whilst I waited for some wire to be delivered.

Next was my efforts to refurbish my old Procat racing machine. It had been sitting in a box for the last 25 years or so but should have all been complete.

Whilst stripping it down for a clean, I realise that the plastic bar that is used to help tension the main drive belt is missing. I have no idea where it has gone or even how it has gone. Looked, and appealed, for a replacement. Finally found a chap who had a NIP set of front diff housings available, which include the required bar. So I did a deal for those.

Whilst waiting for those parts to turn up I thought I'd set about reassembling some of the rest of the car. I got as far as step 3 when I noticed that the 2 drive pulleys from the rear transmission are worn and not really usable in anything other than a shelf queen. More searching and appeals for some replacements have so far been unsuccessful.

In fact, I've abandoned the search for the pulleys and gone and ordered the Cat XLS Pro transmission upgrade, which will solve the pulley problem. However, the pro upgrade includes a new front diff that is apparently larger than the original so requires new front diff housings. So I've also had to order some new housings but that means I don't now need the vintage ones I sourced earlier.

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So a few more to add to the list.

First - the Fox.  Again.  The reason I didn't fit the servo when I assembled is because I didn't have one.  I had to wait until the budgets were topped up before I could place the order.  In the mean time the Fox and all its bits went into the original box and got moved from place to place.

When I came to fit the servo, I counted out the necessary parts from the screw bags - and could only find one of those little metal spacers for the servo horn.  The Fox servo horn is different to pretty much everything else I've ever seen and I didn't fancy going away from the Tamiya design, but those metal spacers are a unique part and I didn't have any in my spares pots.  So I had to place an order for another £15 screw bag for one tiny little washer...

Fast-forward to two days ago when I'm in my studio - the studio with the black carpet - the one onto which I drop screws and never, ever find them - and what do I see glinting up at me?  Yes, that's right, the spacer.

 

And this morning I have yet another one, this time down to my own raw stupidity.

Last night I made up some tow cables from this weekend's G6.  There's a No Hand Of God rule, so to recover a fallen or stuck rig you either use your winch or a tow strap on a friend's rig, or you make an extra-long tow cable with a big hook on the end that you pull with your hand as if you were another truck on the ground (you can only pull in one direction, you can't just pick it up by its roll bar and dump it on its wheels).  I used copper earth wire from some heavy-duty mains cable and smaller copper wire around the row eye, then soldered it for strength.  The wire is just tough enough to be bent around a hammer head or fat screwdriver and hold its shape when lifting a fully loaded rig.

So I made two cables - one for me, one for a mate - and was pretty pleased with the results.

This morning, with my List Of Things To Do getting shorter, I figured I'd make up another tow rope, this one to remain hooked onto the rig so I can easily hook it up to other rigs as we go around.  Well, it took me an absolute age to get the knot done right.  I wanted to set the length exactly so it will hook over the roll cage and stay in place while driving (having to clip your tow strap back on every time you roll over gets tiring very quickly, especially when you have back problems like me).  Well, I tied and untied that knot about 11 times before I was finally happy with it.

I was running right out of rope, so I didn't have much of an offcut left, but I like to be tidy, so I got the scissors to cut it off.  And found myself with a lot more rope than I expected.

I cut the wrong side.  I now have two halves of a tow line...   ...and I'm all out of string.

There's a really good hardware store a few mins' walk from me that will sell a variety of nice-looking string.  It's not open yet and I have to leave soon for work, which is in the city, where there are no hardware stores.  I should be back before it closes, but I'm on Daddy Duty tonight as my wife will be out, so I'll be housebound.

Still - so far I've had a lot of successes on this project, so I'm not as angry as I could be :)

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