Hirobo Zerda: from wreck to runner

[threesheds]

Zerda and 44b chassis (rockn city, Vega) spares take a bit of understanding. Suspension arms come in at least 3 lengths, zerda front zr1 40mm , 44b rockn city etc ct1 45mm and part ct2 for rear of both models 50mm
The symbols in the parts list of the manuals aren't explained but a circle apparently that parts fit . A triangle that they might be adaptable and a cross that they don't fit.

[Dadio]

So does that mean the front track on the" Rock n" models is wider than the Zerda or does the different front C hub designs equalise the track ?

[threesheds]

First: I was wrong, it's ct1 that's shorter than zr1.
At first sight the city castor hub doesn't add more width than the zerda hub/knuckle holder, but currently the zerda front wheelbase is about 10mm wider than the city but that might be due to the different wheels and their offset. I'll remove the wheels and measure again to see where any other differences are.
Also I'll put up some pics.

[threesheds]

I'll post a pic later but on the zerda it's 20cm measured from the outside face of the bearings. On the city it's 19cm.
If anything the zerda hub carrier is a bit bigger than the city castor/hub carrier but only 1 or 2 mm .
I wonder if the castor was found to be a weak point as it looks less beefy than the zerda hub carrier and the zerda has castor nose up angle in the chassis base , on my one anyway whether it's a variation in manufacture?
Anyone got a zerda with a flat chassis base or castor hubs?

[threesheds]

Rockn City and Zerda front ends on a grid of 1cm/10mm squares
It looks like 'castor angle' is a science all of its own looking at other posts on RC10talk.
the city manual recommends 8-10 degree angle which I'm guessing is approx the angle of zerda front end.

[threesheds]

Zerda wreck II
from Switzerland to the UK.
set up as a drift I guess with support/chassis protection strips.
Steering servo with a plug I hadn't seen before.

[Dadio]

That's interesting , I'd say the added rails are intended to compensate for the loss of the top deck , the foam tires might mean indoor or carpet track ? The servo plug looks like the early Futaba plug .

[silvertriple]

I'm going to follow this thread, as I'm another Zerda owner

[threesheds]

Got it mostly dismantled with very few nasty surprises. Mostly missing or wrong size screws. Primary drive belt cover had perished rubber boot but I have a spare if I decide to fit it. Drive belt was over tensioner instead of under it. some old glue to remove. Dadio's 3d printed cage rear fender spare (thankyou) will replace missing part but the rest of the cage is ok if a bit scratched. Wheels of unknown parentage, they'll be replaced with something more suitable. Mabuchi motor may be the bog standard that came with the kit. I've got an alien mid deck which has the same outline as zerda but different cut outs. Diffs look good as new but dry so all in all compared to the sum of cost of it as spare parts not too bad. Waiting for drive shaft cups which I hope will fit (non hirobo) and hope dog bones I have as spares are the right length as it was 2wd which is pointless on a zerda unless you do away with the long drive belt somehow. Saving inspection of shocks for another day

[threesheds]

That's interesting , I'd say the added rails are intended to compensate for the loss of the top deck , the foam tires might mean indoor or carpet track ? The servo plug looks like the early Futaba plug .

Nano servo MPX made in Germany. Wonder if it'd work with a changed plug. Plug costs as much as a new servo probably

[juicedcoupe]

Looks a lot like a Futaba G plug, except that the pins look thick.

[threesheds]

Aaargh the mysteries of zerda pulleys again. The 18t 4mm bore secondary drive pulley too worn to use and rare as hens teeth. Anyone used 16 or 20 tooth. I know I can use three sizes on the motor to adjust ratios.
Seems I can get 5mm bore easy enough and bore reduce with something.
Other issues on this rebuild are the old lubricant which turned to baked marmite and bent pins holding suspension arms either straightened or use spares

[threesheds]

Aaargh the mysteries of zerda pulleys again. The 18t 4mm bore secondary drive pulley too worn to use and rare as hens teeth. Anyone used 16 or 20 tooth. I know I can use three sizes on the motor to adjust ratios.
Seems I can get 5mm bore easy enough and bore reduce with something.
Other issues on this rebuild are the old lubricant which turned to baked marmite and bent pins holding suspension arms either straightened or use spares

[Dadio]

Pretty sure I found pulleys with 3mm bore that I drilled out the 3.2 for pinion/pulleys , probably easier than finding the sleeve or at least more economic .

[juicedcoupe]

Lighter fluid will break down old grease and lubricants without damaging the plastic parts. It's also good for removing servo tape and other mild adhesives.

Regular Zippo or Ronsonal fluids are just light hydrocarbon, naphtha blends.