Baja 5B Electric roller for $345 should I do it?

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Horatio said:
They seem very reasonably priced. If they work well enough, quite a bargain. No worries if you rag them around at that price.
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Could you measure the thickness of the springs on your Baja? The Rovan springs are 2.4mm front and 2.7mm rear, medium Baja springs are 2.2 front and 2.4 rear. So the Rovan comes with hard springs that sound like a creaky mattress by default.
 
Atomic Skull said:
Could you measure the thickness of the springs on your Baja? The Rovan springs are 2.4mm front and 2.7mm rear, medium Baja springs are 2.2 front and 2.4 rear. So the Rovan comes with hard springs that sound like a creaky mattress by default.
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Will do. I'm using IRC Shocks and their lightest spring rate. They tend to be really, really hard.

I'll measure them on new year's day! 👍

Have a happy New year. 👍
 
Horatio said:
Just checked my front and rear IRC progressive springs are 2.5mm, both front and rear.

https://www.innovative-rc.com/product_info.php?keywords=Rear progressive&sort=1a&products_id=773
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Maybe it's the steel they're made from, whatever the case the Rovan springs are really hard, like if you drop the car from 3 feet on asphalt the suspension barely moves.

So after wracking my brain to come up with a solution for the radio box I finally realized there's room for it near the ESC at the other end of the car, you know right next to where most of the the things that need to be connected to the receiver are. That way I only need to run the steering and brake servo leads through the chassis.

As a test I ran it through puddles and as expected water pooled in the radio compartment, also had some water retained in the battery tray so I may add some drainage holes to that as well. As the windows protect the batteries as well as a lexan body I might also ditch the battery tray cover and just use nylon straps to retain them.

This skid plate is not compatible with the lexan lower body pods:

https://www.aliexpress.us/item/3256807251424509.html

But on the other hand it also completely encloses the lower rear chassis preventing it from becoming a grass collector. As well with this installed you only need to remove 3 clevis pins to get the body off.

This bumper is made from a very thick durable nylon I highly recommend it. It is objectively better than stock.

https://www.aliexpress.us/item/2255800304234101.html
 
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Atomic Skull said:
Maybe it's the steel they're made from, whatever the case the Rovan springs are really hard, like if you drop the car from 3 feet on asphalt the suspension barely moves.

So after wracking my brain to come up with a solution for the radio box I finally realized there's room for it near the ESC at the other end of the car, you know right next to where most of the the things that need to be connected to the receiver are. That way I only need to run the steering and brake servo leads through the chassis.

As a test I ran it through puddles and as expected water pooled in the radio compartment, also had some water retained in the battery tray so I may add some drainage holes to that as well. As the windows protect the batteries as well as a lexan body I might also ditch the battery tray cover and just use nylon straps to retain them.

This skid plate is not compatible with the lexan lower body pods:

https://www.aliexpress.us/item/3256807251424509.html

But on the other hand it also completely encloses the lower rear chassis preventing it from becoming a grass collector. As well with this installed you only need to remove 3 clevis pins to get the body off.

This bumper is made from a very thick durable nylon I highly recommend it. It is objectively better than stock.

https://www.aliexpress.us/item/2255800304234101.html
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And so it begins! 😁

The radio box is splash proof at best. Just use waterproof servos and keep your receiver in a balloon if you intend on going through puddles.

Side pods are a PITA. 🤣 Grass collectors we call them here in the UK.

Perhaps you fancy something like this?

31076.webp


https://www.boneheadrc.co.uk/product/bonehead-sym-steering-kit
 
Horatio said:
And so it begins! 😁

The radio box is splash proof at best. Just use waterproof servos and keep your receiver in a balloon if you intend on going through puddles.

Side pods are a PITA. 🤣 Grass collectors we call them here in the UK.

Perhaps you fancy something like this?

View attachment 11388

https://www.boneheadrc.co.uk/product/bonehead-sym-steering-kit
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Not compatible with the battery tray. The E-baja has the servo tray and battery tray combined into one unit.

s-l1600.webp



Did a speed test today, 58.2mph with an 18T pinion on asphalt. Battery was a just a bit below fully charged. Also this thing does not wheelie on road the wheels will slip but the nose never comes off the ground.
 
Atomic Skull said:
Not compatible with the battery tray. The E-baja has the servo tray and battery tray combined into one unit.

View attachment 11401


Did a speed test today, 58.2mph with an 18T pinion on asphalt. Battery was a just a bit below fully charged. Also this thing does not wheelie on road the wheels will slip but the nose never comes off the ground.
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58.2 mph is an impressive speed! Well done. Now try some 0-40 mph runs. 👍
 
Horatio said:
58.2 mph is an impressive speed! Well done. Now try some 0-40 mph runs. 👍
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It was sphincter tightening but not unstable at that speed, I may eventually try a 19t or 20t pinion temporarily just to see how fast it will go but for general driving I think the 18T is better.

EDIT: The RC talk calculator was pretty on the money it said 62mph at 50.4v and accounting for the slightly less that fully charged battery and voltage sag 58mph is about right.
 
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Ok I'm pretty sure the center chassis and rear chassis plate are steel not aluminum, no wonder it's so heavy.
 
Horatio said:
Really? Have you confirmed this with a magnet? I think they're just stamped aluminium alloy.
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Ok I was wrong it's aluminum. The rear chassis plate appears to be stamped and painted rather than milled and anodized which is what confused me.

The first version of the HPI Baja 5B in 2006 used a steel chassis , the aluminum chassis was introduced in the next revision in 2008 I believe.

Are these polymer chassis worth it?

https://www.ddmracing.com/Kraken-RC-X3-Polymer-Chassis-with-Steel-Insert-for-HPI-Baja-5b-5T-5SC
 
Was thinking that this combined with the polymer front chassis would help reduce the weight while allowing some flexibility that could prevent it from cracking at the overlap.

https://fearlessrc.com/product/rv65002-1/

My first thought about the CF rear plate was that having a rigid lever attached to it (the front U channel chassis) could cause eventual cracking where the front and rear overlap. The plastic chassis is very tough but also more ductile than aluminum which could prevent that.
 
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Atomic Skull said:
Ok I was wrong it's aluminum. The rear chassis plate appears to be stamped and painted rather than milled and anodized which is what confused me.

The first version of the HPI Baja 5B in 2006 used a steel chassis , the aluminum chassis was introduced in the next revision in 2008 I believe.

Are these polymer chassis worth it?

https://www.ddmracing.com/Kraken-RC-X3-Polymer-Chassis-with-Steel-Insert-for-HPI-Baja-5b-5T-5SC
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6883.webp

Here's my original chassis from my SS that I received from Stormer Hobbies in July 2009. It's definitely anodised aluminium.

6882.webp

And the Woven Carbon Fibre composite chassis.

The only positives with the 'polymer' (plastic) chassis is that it's cheaper than an alloy chassis and slightly lighter.

Obviously, if you want light and stuff - Carbon is the way to go.
 
Atomic Skull said:
Was thinking that this combined with the polymer front chassis would help reduce the weight while allowing some flexibility that could prevent it from cracking at the overlap.

https://fearlessrc.com/product/rv65002-1/

My first thought about the CF rear plate was that having a rigid lever attached to it (the front U channel chassis) could cause eventual cracking where the front and rear overlap. The plastic chassis is very tough but also more ductile than aluminum which could prevent that.
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https://www.boneheadrc.co.uk/product/bonehead-chassis-plate

31679.webp


I have one of these on my shopping list. Bonehead stuff is top tier. Comes with carbon washers.

My rig still has the original SS orange motor plate!

It was fairly common to bend these - mine is alright though, so never had enough motivation to change it.
 
Horatio said:
The only positives with the 'polymer' (plastic) chassis is that it's cheaper than an alloy chassis and slightly lighter.

Obviously, if you want light and stuff - Carbon is the way to go.
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I would think that it would be tougher as well. Where aluminum would bend and stay bent (plastic deformation) engineering plastics like nylon and delrin will flex and return to their original shape.

In my experience with plastic vs CF parts in large helicopters CF is stiffer and lighter but doesn't handle crashes as well. CF will splinter where plastic survives undamaged. Or put it another way, throw an injection molded nylon milk crate down a mountainside along with a box made from CF plate and aluminum bosses, which is more likely to make it to the bottom in one piece?
 
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Atomic Skull said:
I would think that it would be tougher as well. Where aluminum would bend and stay bent (plastic deformation) engineering plastics like nylon and delrin will flex and return to their original shape.

In my experience with plastic vs CF parts in large helicopters CF is stiffer and lighter but doesn't handle crashes as well. CF will splinter where plastic survives undamaged. Or put it another way, throw an injection molded nylon milk crate down a mountainside along with a box made from CF plate and aluminum bosses, which is more likely to make it to the bottom on one piece?
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🤔

Erm. I'll bear that in mind the next time I consider chucking my 16 year old Baja down the side of a mountain. 🤣 So far this hasn't happened, so I'll live with it.

Obviously, catastrophic failure will result if an impact or damage causes delamination to occur.

Again, I'll keep that in mind when designing an RC milk crate.

On the other hand, if I want an RC racing buggy that is exciting to drive and handles and responds like a racing car (rather than a boat), I'll attach the front and rear ends to the stiffest, lightest material I can. I'll leave the suspension arms and dampers smooth out the rough stuff and in return, I will make every effort NOT to crash and keep my rig on it's wheels, rather than it's lid.

Horses for courses. If I wanted an entirely plastic car, I'd have bought an Xmaxx. 🤣

Or strapped a brushless motor and wheels to a milk crate if I was feeling strapped for cash. 😝
 
Atomic Skull said:
I would think that it would be tougher as well. Where aluminum would bend and stay bent (plastic deformation) engineering plastics like nylon and delrin will flex and return to their original shape.

In my experience with plastic vs CF parts in large helicopters CF is stiffer and lighter but doesn't handle crashes as well.
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It never ends well when people dink their RC helis.

FPV racing drones are generally made out of carbon fibre, because it's light, stiff and durable enough if the design is right.

There's a compelling case for Woven Carbon Fibre for simple chassis designs over alloy. If a chassis is laid-up right, the combination of lightness, stiffness and durability can be honed to perfection.

In the case of the Baja 5B, the chassis being a bathtub design means it is inherently stiff, so to delaminate a Carbon chassis, you'd have to have done something ridiculous.

The 5B isn't really a jump rig or extreme Kevin Talbot basher.

Better stick to milk crates for that, or 4WD, M2C laiden machines. Plenty of videos detailing that kind of crazy stuff. Stephane Z here lands his crazy jump rigs perfectly - manages not destroy his machines constantly.

The Baja is a 5th scale, classic 2WD buggy desert dweller, designed by the same person who brought us the Kyosho Ultima. The similarities are quite apparent.

It was always HPI's vision to see these rigs race in a proper, popular series.

https://www.hpiracing.com/en/article/view/2011061702

Large Scale races up to that point had been limited to FG and Yankee, which whilst high quality offerings, were dated and simply weren't as popular as 1/10th and 1/8th scale for racing.

Now we have all the fun of the HPI Baja, with the convenience and torque that brushless systems afford.

Your rig - your rules. Only you can decide what parts you want to change and why.
 
Hard to resist ramping it off parking lot speedbumps when it flies 6 feet into the air and a 15 foot span so effortlessly. The acceleration on this thing is hardly different than my 6S 1/8 cars maybe a little better.
 
Would someone care to help me understand where Losi, Rovan, and HPI all fit together with these rigs? Are they a shared open design? Or did someone copy the other when a patent expired? What are the differences? Who currently makes what?
 
danl said:
Would someone care to help me understand where Losi, Rovan, and HPI all fit together with these rigs? Are they a shared open design? Or did someone copy the other when a patent expired? What are the differences? Who currently makes what?
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What I gather is that HPI discontinued the Baja 5 platform and tried to move on to more modern designs but there was still a demand for the Baja 5 so Rovan stepped in and started making a "compatible" clone which remained popular. HPI was upset about it but eventually they gave up and brought back the original Baja 5.

My understanding is that the plastics in the suspension on the Rovan version are more chunky and less optimal for racing but more optimal for bashing. The battery tray system in the electric version is also somewhat different between HPI and Rovan, neither are good as delivered imo and I milled out the partitions in mine to make more room and ditched the lid in favor of straps.

I have an idea for a better more roomy battery system that would use the sides of the chassis itself as the walls of the battery compartment, I'll circle back to that after I finish this thing and get it tidied up. Right now I still need to figure out how to mount the servo for the front brakes install a radio controlled light switch and tidy up the wiring for the lights. I decided to forgo a radio box entirely and instead waterproofed the receiver by filling it's case with neutral cure electronics silicone leaving only the pins exposed, an idea I got from the Flysky epoxy potted waterproof surface receivers. I used a 3x6 2.54mm pitch female header wrapped in teflon plumber's tape to keep the silicone goop off the pin strip while it cured. The bind button is now entombed so the receiver can now only be bound to a transmitter in wireless mode but that's not really a problem as I've never used the bind button mode anyway.
 
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