Hirobo Bearcat SS - Let's start something else...

[silvertriple]

Bormac's midships reshuffled a bit my pipeline of work. In the plan, I wanted to go thru the Samurai model (and still want to go thru it), but since I need to tear down the number two to restart this, I'll start the car that was planned after the Samurai...

I located last year a shop (not exactly nearby), with a guy passionate about vintage. Each time I get there, we can talk for hours... While I was there in September last year, he talked to me about a car that may be of interest for me... I got it in December. It's almost complete, I'm just missing a driver figure.

It's an Hirobo, and it's one of the 2WD models they made. There was 3 variants based on the same chassis : Bearcat SS, Bearcat and Tomcat...

I got a Bearcat SS. ABS bodyshell (the front bonnet), monoshock for the front, shock cylinders in plastic, roll cage and no wing.


The differences for the variants were as follows:
Bearcat - Lexan body shell (there was the roll cage under that one), wing, and metal shock cylinders, with a monoshock at front.
Tomcat - Lexan body shell (the front bonnet), wing and roll cage, metal shock cylinder - one per wheel. The position of the shocks at the front left many people thinking that it was the same as the bearcat, as the second shock was relatively hidden under the bonnet.

The chassis and arms are the same.

I packed the Midships, and therefore, I have a box empty waiting for a car to get down to parts . The Bearcat SS found a new home .

Work plan : get the car to parts, cad it, clean and restore.

I decided to remove the wheels today. I started by the front right wheel, and it did not start well: I can turn the nut, but the axle goes with it. No issues for the 3 other wheels, but I will need to find a solution...

[silvertriple]

Got the car almost tore down to parts today... Some bad surprises, it seems that the car was not stored properly and rust made some bad things...

It started yesterday with the right front wheel. Today, I decided to retry differently, and it did not happen well.


I guess I will have to find a new pair of knuckles or to adapt some of a Kyosho Scorpion re-release (the first one that came to my mind, as I have a Turbo Scorpion on the shelf next to the box where i store the in progress project).

Once this was done, I started to take the roll cage to parts. A few screws and I know already that I will need to go to metric screws everywhere to replace the screws being used and the threads slightly damaged in some areas...



A few screws later, the top deck is removed. I removed the MSC (seems it won't be of use as the tracks are dead). The servo saver is mounted on top of a standard horn, and I thought initially it was not the standar way, but the manual shows it this way



Both chassis parts will require a good cleaning. That being said, the bottom chassis is clearly no plane anymore on the rear side (the motor is going down on the left side).... I follow the manual in inverse sequence and did start to put down the front train first...


While the bumper is still in one single parts, the screws are bended. Seems this car was a lot of fun for someone...




Once the front train is done, it is time to take care of the rear... The belt is here and in good state


The gearbox is fixed by 7 screws...


And once that is done, you can remove the arms from the chassis


I removed the motor, I have no clue if it is a good motor or not, I will do some search at some point...


Then I had to take care of the gearbox



Outdiff and spur gear are not moving from the axles.. I will need to use a WD40 bath for some time to deal with this...

For now, everything is back in the box. I'll start to model this within the next days/weeks.

[silvertriple]

Opened a new CAD project today... Took the rims out and started to defined them...

Few minutes later, that was fairly quick, I get both front and rear rims in.



I'll probably set some version with inner rings at some point, as well with easier to find bearings... And maybe hex drivers instead of friction (although friction works well with printed wheels)....

That was fairly quick for today, but don't expect this to move as quick as Bormac's Nichimo, as I do not have to send this one back to somebody

[Dadio]

Id put good money on the diff and red pulley being the same parts as the Zerda .

[silvertriple]

Likely, very likely!

[silvertriple]

Some issue with an expected delivery, and I can't do what was planned today...

Therefore, took at suspension components from the Hirobo, and check for the symmetries...


I focus on plastic part first, which explain why there is no tie rods.

I started by the rear...

Arm first...


Arm support then...


And then the carrier.


Which give me this at the end...


I did not look at other Hirobo manuals but I would not be surprised if those parts are common to the 44B chassis. I've look at the diff, and it is likely the same on other Hirobo cars...

Globally, this car should be easy to model. I'm not sure the chassis will be printable as it might be too long for MJF, which means it would require some adaptation for printing eventually...

NB: spot the mistake in my pics

[Dadio]

None of those suspension parts look like 44B , Zerda or Alien Mid so far .

[silvertriple]

None of those suspension parts look like 44B , Zerda or Alien Mid so far .

I checked after posting, and you are right. For the diff, though, I believe we can say it's the same...

[Dadio]

If you want a nice model of the big red pulley you can have the one I did or at least you can compare the parts to see if they are the same .

[silvertriple]

If you want a nice model of the big red pulley you can have the one I did or at least you can compare the parts to see if they are the same .

Let me model it first, and we compare, then

[Dadio]

If you want a nice model of the big red pulley you can have the one I did or at least you can compare the parts to see if they are the same .

Let me model it first, and we compare, then

Ok

[silvertriple]

For the mistake, I actually put the arm upside down when I did the joints... This is corrected.


This afternoon, I applied liquid mask on the Fantom bodyshell, and while each layer was drying, I was doing some CAD activity...

Pursue on the front side, now... I started by the Arm support this time.


Then the right arm...


A small curiosity : the front arms are not symmetrical, although the non symmetrical is of no use on the Bearcat SS and the Bearcat. Both were ready for the optional shocks of the Tomcat (2 instead of the monoshock).
I did a mirror before applying the non symmetrical part, and that is basically the reason why I started by the right side.


And I just applied the joints at the end...

[silvertriple]

Still working on the front train...

King Pins are very easy to model...


Then comes the knuckles, and let's be clear, this is likely the most complex car to model on this car

The part holding the pivot ball is angled, but while the angle is easy to define (same as the chassis kick up, 20°), the work to put it in CAD involves multiple bodies to get it right.


I got up to 11 bodies for this small and unique part, to finish with just one at the end by combining all of them...


And it remains to add the axle component (which is an issue somehow, and a frequent one, apparently, as the axle is out of the knuckle for the right one. Fortunately, I found a cheap set of brand new knuckles in France and it arrived yesterday).


Last, I added the joints and get the front train components I add on my table when starting the arms parts

[silvertriple]

I opted to pursue the tasks with the gearbox...


One asked me why not starting by the pulley and differential... I have an issue with both : no way to remove outdiffs from the differential shafts, and no way to remove the shaft from the pulley. I'm not really sure what happens here : the grub screw have been removed, the pulley turns freely around the shaft, but no way to get it sliding off the shaft...


Any case, for the time being, I'm going to work on the gearbox parts...
I defined first one single sketch with my main dimensions


On this one, I won't use the shell command : it's super simple first, and secondly all the wall don't have the same thickness...

It was quite quick to get in (3 sketchs). There is a subtility, as you actually need to do the mirror before applying the last sketch to get the right side quicker...


Here is the reason : the wall end is subdivided in two parts to make the gearbox watertight...


I took the mirror I created before last step to work out the right side. There is a difference as the bearing cage is reinforced. Funny, the bearing was broken inside


And we have the gearbox case...

[Dadio]

I don't know if it helps but all the shafts on the Zerda have machined flat areas for set screws to locate , maybe a burr is catching on the flat area stopping the shafts coming out .
As an old mechanic I had to give this advice to my apprentice's many times " Use More Force Luke"