Modifying prebuilt junk, in stages, to be less junk like.

[SternWake]

Still feels like cheating rolling solo to the parks without Fiona in tow.

Pulled enclosure to put a straight edge on baseplates and aligned them, and got the rubber risers hot and stopped twice to retorque in a 12 mile solo roll.

Definitely want to dewedge rear and drill new holes further up for front truck and just subtract riser height until wheelbite can only happen at easy step off speed when standing on heels or toes.

The mini is quicker than the midsize, but i can ride the midsize faster with a lot more comfort and it has 360wh instead of 144

I’m taking too long on the guppy’s deck so I figured get the midsize aligned since it was crabbing and go for longer rolls

I am liking it with the airless rubber 107’s more and more., but when ibget home and take out the mini I appreciate the nimble silence.

Its good to ride different boards.

Its nice having two ready to roll and work on the third.

[glyphiks]

Yeah its definitely nice having a working board at all times.

Going back to the thin epoxy, have you tried fused silica as a thickener? Milled fibers suck, but fused silica gets a much smoother, easier to sand finish and does a good job of thickening if you use enough of it

[SternWake]

I do have some cab-o-sil, which is a brand name of fumed silica

I used the milled fibers in the overdrilled hourglass shaped hardware holes for added strength, and since it doesn’t thicken the epoxy it was still able to wick deeply into the wood fibers, but i did use a cotton swab to presaturate un modified epoxy into the bare wood first.

The truss head bolts will not be able to sink, and the wood wont be able to absorb water should any get past the heads.

I generally use wood flour as a thickener, and add milled glass fiber(first) to it for added strength.

[SternWake]

Below is a 5.5x2.5 connector that came from Ebay. Claimed a 10 amp rating. Has a right angle clamshell housing. I have stuffed 14awg into that clamshell housing, and have passed 10 amps continuously with no issues and no excessive heating.

I am surprised it worked as well as it did/does.

The longer ground contact is attracted strongly to a magnet, but the rest of it is not

Below is a Switchcraft 760 5.5x2.5

not attracted to a magnet.

The Fit into a Generic ‘10 amp’ 5.5x2.5 receptacle is very tight.

Both measure 2.56mm at the very opening of the plug

The back of the .94 gram plug is open and also measures 2.56, and 2.58mm if I really torque the caliper thumbwheel

The back of the Switchcraft 760 is closed, but looking down into it I think I can see it taper, So it can grasp the pin firmly.

I have another switchcraft 5.5x2.5mm, but this comes with a theaded locking collar, Which I cut off with a dremel, so the body is longer.

I wanted a lowest possible profile connector for the portacharger so I can run wires at 90 degrees tucked in tightly against enclosure, so the larger heavier one sort of defeated that desire

Inside this Mouser order was 18 Panasonic LOW ESR 63v 100uv capacitors.

I want to add at least 4 and hopefully 6 in parallel to my ESC with a cap bank.

A different design than this, but the same general idea.

How to make your own cap pack step by step

[glyphiks]

How long are your battery leads?

[SternWake]

Not long enough to blow up my ESC after 2400miles.

I do have significant ‘loop area’ and uneven length wires between battery and ESC, both which increase inductance.

[glyphiks]

Have you done any calculations around estimated inductance and capacitance required or are you just winging it with the 400-600uf cap bank?

I read more about my fear of ‘over-capacitance’ and it seems like i was probably a bit over the top. It seems the only real issue would be if there was even a small short on the esc side that may be inconsequential without a cap bank, could be exacerbated by a cap bank dumping energy into the esc… i don’t see how any esc side short could be inconsequential, so over capacitance may just make a blown esc even more spectacular

[SternWake]

Glad you chimed in with a good question.

I have not calculated the extra inductance caused by my battery cabling’s ‘loop area’ or the unequal lengths of that and my loopkey harness.

Perhaps it is inconsequential, but Ideal would be equal length wires run as close as possible to the ESC from where thely leave the battery. My next battery build will be with this in mind, but for now My batteries are healthy AF and I am not going to change their wiring.

“As much Capacitance as I can fit and still keep 10S from frying the resistor in an XT90s loopkey”

Is my current mindset.

A situation AI described where too much capacitance might cause an issue with High end ESC’s boot up procedure, seemed unlikely to be an issue with my relatively low power ESC.

A eye told me three different times asking it slightly differently ways from 3 different angles that ~1700uF of total capacitance at 10S voltages before the resistor in an XT90s connector Is in danger..

I know the risks of trusting Aeye, and am taking them anyway.

My ESC comes with dual 470F 63v caps, So 940uF. So adding 6 100uF caps brings me to 1540uF.

The more caps in parallel the lower the ESR.

The closer the Cap bank is wired to the ESC’s included Capacitors, the better. No long pigtails, not only’ for best results’ but apparently ANY results.

The shorter the capacitor’s legs and that wire run to the ESC input, the better.

I looked at some photos of my enclosure and estimated I could fit at least 4 and perhaps 6 of these side by side on the side of the ESC as close as possible to where the battery wires enter.

I have 3 ESCs, 2 in use, So I ordered 18 of these caps.

This is my Original 10S Hub motor Puaida branded /Lingyi made ESC I bought in late 2023

This one had issues with remote disconnects when I used it with a power button, and then a new power button too. With No power button, use push to start, auto off, loopkey backup. No more remote disconnect issues in 1800+ miles, but sometimes roll to start requires a loopkey cycling.

It is the same size aluminum bathtub, and power and phase wire layout as the Newer Puaida ESC that currently inhabits both the Mini’s, and the Guppy/Midsize’s kicktail shared enclosure.

it looks like 6 should Fit.

I am going to build a 1P 6s flat pak cap bank and treat it as a skinny long wart whose heatshrink can be adhered properly to the side of the esc.

I don’t have immediate plans for this older ESC, but CAP BANK, number 1, will help #2 an #3 come out way better

The mileage I have accumulated on these ESC’s with my current levels of induction, would point to ‘Aint broke, dont fix it’

But most of My mileage is without the additional range extender battery, which more than doubles the inductance and resulting voltage spikes my ESC’s capacitors have to deal with.

I do dream of loading up with all my 10S batteries to run in parallel and all my 7s batteries to power my portacharge and roller , and All my 5s and 6S batteries which can power my other free floating CCCV boosters, and carry some 60-80 miles of range.

If the booster and additional paralleled batteries, cause the inductance and the voltage spikes and ripple to get out of hand, …If then my ESC Shits the hallway……

Perhaps this cap bank will reduce and delay or eliminate the chance of a loose turd in the hallway.

[glyphiks]

Yeah i think I will try and do all the calculations for my setup, mostly out of curiosity, and then follow suit with just putting whatever caps will fit nicely in there.

I also am unsure of how necessary all of this stuff is, but it’s fun science

[b264]

@SternWake

[It’s] nice having two ready to roll and work on the third.

This is the way.

[SternWake]

I view excessive ripple as cumulatively damaging to the CAps and mosfets

Voltage spikes caused from that electrical water hammer, how many ESCs are blowed up because of it?

Excessive loop area, where power wires do not run in close parallel cause more inductance and inductance is basically electrical inertia.

So when at half throttle the PWM is 50% on 50% off and the voltage ripple is at its highest, and then one slams the brakes and one of those electrical water hammer pulses causes voltage to spike 20% higher than the rating of the Capacitor.

Perhaps wire inductance and under capacitance can be the primary cause, or a significant contributor to ESC failure.

I dont know, but I dont think I will cause any damage, and perhaps it will mean a happier ESC, especially when i am running parallel packs and or portachargers

I see some smaller 50V rated capacitors on my ESC.

[b264]

Unequal lengths shouldn’t matter for battery wires, but total length does. If they’re long, make them bigger and/or figure out how to put the extra length on the motor phase wires instead, which can be very long.

[b264]

What are you using for power switching? Generally, adding capacitance will be rough on the power circuit.

[SternWake]

I use XT90s on my batteries and a loopkey.

I quit using a power button and just use push to start and auto off.

I have never used a power button on my 2400+ mile ESC, and i dont pull my loopkey very often.

My battery cabling and loopkey harness is 10AWG.

not worried about resistance, but inductance, and supposedly, unequal wire lengths from battery to ESC and when they do not run in physical parallel, both increase inductance, and that inductance increases ripple and voltage spikes.

[SternWake]

I downloaded Pics from my Phone onto desktop last night.

The last time I did so was march 8. When I took Fiona back from the emergency room and called the at home Euthanasia vet, and she protested so loudly I called it off.

This is a screenshot pic from the Next day, rolling our favorite traffic circle at 20mph:

[SternWake]

I found this video pretty interesting, where the guy measures ripple voltage at the ESC, and his maximum is measured right around 50% throttle.

Why I Don't use a Cap Pack in a Speed Run RC Car - Castle 1721 2400Kv on 8s

[SternWake]

The 9 degree Bubinga Splayed foot wedge risers have caused the 10-32 baseplate hardware to take on some 9 degree bends with 1800 miles and several re-torquings.

I have decided to redrill 6 new hardware holes Perpindicular to the baseplate and at 81 degrees through the Guppy itself.

This will leave the new 10-32 Truss head hardware at 81 degrees too, but I can remedy that so they sit flat, nestled in Epoxy ‘washers’ spreading the load evenly. The white sheet below the truck is 1mm thick clear silicone sheeting.

I put it there along with s piece of the teak Chariot handle so the Clamp could spread the load and Not slip during drilling. This worked amazingly well without having to really crank the clamp super tight

A dab of hot glue kept the sliding square base attached so I could drill perpendicular to baseplate through the Wedge riser and Guppy together

The 1mm thick silicone sheeting provides incredible traction. I am going to use it on both sides of wedge riser instead of Innertube tire rubber below and a regular rubber shock pad under the baseplate. This is the rear truck baseplate^

The front truck is getting moved forward by about 12mm and will get new 81 degree holes drilled through wedge risers and the guppy.

This will allow me more turn before wheelbite, and I can roll the board carryng the kicktail, either right side up or Upside down. The holes in the guppy are fingerholes for walking the board

With the hardware torqued on the grippy silicone, I believe they cannot slide forward and cause the hardware to loosen. If the wedges Do migrate backwards, I will epoxy them in place, But I would like to not have to go so permanent.

I was making decent progress sweating balls in the garage Aligning the baseplates and prepping for drilling, when I was swarmed by mosquitoes.

I will be further shaping the Bubinga wedge risers to make them a little more Ferrari and a little less 1980’s Lotus Esprit before sealing them with more epoxy.

More Diagonal FG roving will Go below the Wedges to help reduce flex and Spread the baseplate loading more evenly.

[SternWake]

‘While it is apart’ is as bad as ‘ analysis paralysis’ as it combines the former with the latter.

When I last added Roving to the deck I guess i said ‘f’ it and did not complete the full diagonals before just literally sugar coating the deck for grip.

The road side is mo better, but still incomplete.

The deck is not too flexy, but flexy enough that reducing it further is not a concern.

Quick recap on this deck, I made it in summer 2003 with Finnish Baltic Birch aircraft grade plywood. 3 Mahogany stringers and I used Biscuits and wood glue, and the seams split in some parts after a few dozen miles. Wish I used epoxy instead, but listened to bad advice. I put this deck away and made another with same wheelbase, without stringers and used that for a decade before breaking it.

I then pulled this deck out of storage , made some White Oak butterflies to join the split seams, and chiseled and routed the deck to accept them. The seams stayed together but the Deck started getting more and more flexy, bottoming out when Pumping.

More roving got added at least 3 different times and twice since I electrified this deck.

The perimeter I carved a cove and laid in a lot of roving unidirectional fiberglass rope extending the width at least 3mm on each side.

While not fully cured I painted the deck with epoxy, Sprinkled raw brown coarse’ turbinado’ sugar, all over it, then promptly knocked it off the Elevating stands, and it landed upside down on the floor cardboard and left a perfect imprint of the outline and diagonals, and ruined the Sugar grip on the edges and roving diagonals

Next day I redrilled the hardware holes, and hunted for sharp edges and just reassembled it, despite not being satisfied. It was more important to roll with Fiona, as that was such a reward for us both.

I was expecting the board to lose more flexibility than it did, and put another 1800 miles on it.

Now that Fiona has passed, I have begun to work on it again, with the drivetrain transferred to my Midsize kicktail for longer distance higher speed solo park runs, and my Mini lightweight carve machine is also fully operational.

I will be adding more to the roving perimeter, as the deck is a bit narrow to exert the leverage I want for low speed turning radius, and I want to fill in the missing roving diagonals top and bottom. I am intending on making a stomp pad from roving for my Back foot, and also incorporating perimeter roving bridges so my velcro cinch straps do not need to cross over the deck, unless I am carrying my Range extension methods.

The 107mm airless rubber hub sleeves have made this board pretty dang comfortable, and while I can get going as fast as I want, and I love the silence of the hubs, I would like more torque, but Hub motors of course limit that.

So for now i will accept it, but will be thinking of a more powerful drivetrain to swap onto this deck at some point in the future, and probably design and build a segmented enclosure that can flex with the board.

I am more or less relying on the velcro cinch straps to give right now, but The enclosure I made is so stiff it can reduce board flex if I strap it really tightly. But then the velcro rearmost cinch strap only lasts 100-200 miles before it rips, or Just one big bump without unweighting the back foot.

[SternWake]

This was the midsize kicktail’s new Semi Squat Stance with an 8° dewedging rear teak riser, and the front truck baseplate moved forward about 10mm and enclosure by 5mm.

Wheelbite at hard angles at walking speeds still possible, but acceptable.

The dewedging of rear truck only, really helped the board perform more towards my desires, especially at speed, but I wanted more front truck steer per lean.

I wanted to wedge the front teak riser pad in same dust making session, but the Mosquitoes found me.

The Pic below is with the quick and dirty no wedge front teak riser shock pad sandwich.

I need to cut its 10-32 hardware to length, later.

Below shows the front RKP truck which came with this deck. This was a 279$ 7s2p JKing hb2 that came with 83mm hub motors in October 2023. The wobbly stock splined 3/8” kingpin has been replaced with an M10 grade 10.9 bolt. No more wobble.

The masking tape holding my full size enclosure gasket is torn right where wheelbite occurs right on the edge of the flange. I will attend to this later on. The flange is thick with a much thicker than needed perimeter gasket.

The Shockpad under the teak can be eliminated once I clearance that flange.

The 8° wedge riser on front and 8 ° dewedge riser in rear made this board feel far better underfoot than it ever has performed before. I was able to carve my racetrack with far more confidence and far less thinking. It just felt so right. The 107mm airless rubber freeroll is poor in comparison to urethane, and significantly louder, but way more comfortable and traction on wet roads is impressive.

The lighter colored diagonals below were first carved through the epoxy sugar grip with a carbide burr. I will lay a glass fiber roving strand into each one of these, not pulled super tightly as this side is under compression when loaded. The perimeter will get a lot more roving too. I want there to be a little bit of a lip, and more width, but the width will come after the diagonals and Lip are laid and the hardware holes are filled with epoxy and milled glass fibers

I decided the easiest and most precise way to turn my flat teak risers into wedge risers was by hot gluing the riser to a square 2x4 and using my Sliding Mitre saw. I have a new Ridgid/AEG 18v hot glue gun, that has 3 heat settings. The Black hot glue will not flow on level 2, it needs level 3. 400+°F / 204.5 °C.

The Claimed 90 second heat up time only applies to level 1, but level 3 is under 4 minutes.

Removing the teak riser from the treated 2x4” was not too difficult, Didnt need the IPA.

I am very happy with how this board feels underfoot now, even though I still need to loosen the hardware and run a straight edge between the baseplates to align them perfectly. I only eyeballed it for the test ride.

IF I clearance the enclosure flange lip, I can then replace the 4mm thick rubber shockpads with 1mm Sheet silicone, and the lower ride height should only help it feel even better.

That will not happen anytime soon though. It’s very ridable as is, and my efforts will go towards the Guppy and keep this as is for the Daily head clearing roll to the park and far hood..

Next time I remove the Full size neoprene gasket from this enclosure, I hope to add the new CAP bank to help protect the ESC from ripple. I did a little bit of wire rerouting to reduce the Inductance increasing ‘loop area’ from battery wires to loopkey harness.

[b264]

That’s a LOT of extra capacitance. Are you sure you need that much? More isn’t always better. Maybe you could try like a sixth of that, and located as close to the ESC as practical.