15th-Jan-21, 06:12 PM
Black Arrow - Black Bull
Given that Black Arrow is not a homologated manufacturer at my home club, what possessed me to engage in this notoriously difficult kit build?
"What do you want for Christmas dad?"
Hmm....
Which kit is going to challenge me during CoViD lockdown-2?
Which kit would be a useful weapon at other clubs and venues? Maybe wood tracks?
Which kit has presented BIG problems for other builder/racers?
Black Arrow are not typically available from UK suppliers.
SlotCarUnion supplied the kit
The car is a 1/32 scale representation of a Laborghini Murcielago.
The kit arrives in a cardboard box, no crystal display case or instructions included.
In the box are several zip lock bags containing all of the parts.
The component count is above 60 of which about 40 constitute the body components. A simple build this is not.
Very small parts are part of this build. There are even front and rear tow hoops which are indeed very small.
Job 1. Find the build instructions and lay the components out.
PDF available from black arrow's website for the build of the body only.
Split the components into "chassis" and "body" and began construction.
I immediately hit a known issue with the motor mount.
(Noted by an experienced builder, Alexis "in Greece" Gaitanis on another forum)
The sioux motor will not fit into the mount without bending the lower motor connector through 90 degrees.
I entertained the idea of drilling the motor mount but this is would have left its strength dangerously compromised.
A tip here is to use needle nose pliers to hold the connector in place while it is being bent. With pliers in place, no stress is put on the connector and a good 1mm radius can be achieved. The motor mount is chamfered at the point where the connector exists the motor end can so its not too hard to get this fitment right.
The motor mount is untypical in that the motor can move and be locked into position to optimise the gear mesh.
It might even be possible to use slightly differently sized crowns and pinions in this mount.
Suspension on a factory fit kit!
The blackbull is supplied with a 4 point suspension and black arrow Red springs.
For all other manufacturers , suspension is a post factory upgrade option.
The motor mount 4-point is not rectangular (not like a slot.IT mount) but is arranged as a front centre pivot, a rear centre pivot and a pair of outer pivots, left and right.
Apart from the motor issue, the chassis build was a pleasure.
Everything fitted. The guide is the best precision fit i have ever seen yet it swivels cleanly and self centres perfectly.
The factory fit braids look really good. No need to retrofit my usual NSR 0.2mm race braid
Building the body would only be a pleasure for a masochist.
I had made a decision to build the kit as per factory spec. No upgrades, no lightweight interior, no lexan crystalwork replacements etc so I diligently followed the PDF instructions.
Slavishly following the instructions left me with a roll cage in the (inevitable) small collection of small pieces left over.
The roll cage is not shown in the instructions. Pulling the interior out to to fit the roll cage invites refit problems.
The most challenging part of the build came from the small parts, especially the small photo etched grille work.
None of the etchwork fitted properly. The rear centre grille is shown as a complex 3d shape (in the instructions) but the actual item is dead flat. The instructions state "use flat plate to adapt photo etched parts" but there is no way to achieve this so the grille was installed as a flat piece.
The decalwork was somewhat problematic with some of the decals fracturing while being wetted for fitting.
The wind screen black surround decal fractured and had to be cut into a single sun strip.
The lightning strike decals are very skinny and required a lot of care to stop them breaking during fitment.
The "black arrow" decal for the rear wing is white which will not work on the white wing.
I painted the window wiper black because I found the white plastic didn't look right.
The car would look better if the white parts were all cast in black.
The wheel trims fitted without fettling.
The mirrors fitted easily.
The front winglets were difficult to fit (2 each side) because they are so small.
Crystalwork fitted well apart from the rear motor view triple hexagon window (supplied as 3 separate parts, not the single unit shown in the instructions) and required glue because the fitting pegs did not align to the windows.
On the rolling Road, the black bull pulls 8.4 metres per second at 12v, higher than factory fitted kits from other manufacturers.
The gearing is quite long for a factory fitted car.
Crown 30 teeth, 16 mm diameter
Pinion 13 teeth, 7.5 mm diameter
Wheel diameter in factory fitted tyres. 20mm
Ratio 2.3
Rollout is 27mm per rev.
The completed model (in factory trim) weighs in at 79g.
------------------
Was this car "Designed for a job" ?
This model is unique and contradictory in many respects.
The main contradiction is that this kit does not know whether it is a shelf queen display car or a "race it like you stole it" car.
There are sooooo many small and fragile components.
The rear wing supports will certainly not survive impact, making those on the Racer Sideways Huracan look very sturdy in comparison.
The Sioux motor is listed as zero downforce leading to the conclusion that this car was designed for a series where flux leakage is forbidden.
So, my best guess is that this car was designed to race in a Spanish "no downforce" formula, possibly against sports cars like the NSR Mosler (fitted with Spanish King motors?)
On paper, the black arrow would be a match for a Mosler of this specification.
--------------------
Did I get this car for "a job" ? Yes.
LSC Wood Green club has separate classes for "Sports Car" and "GT".
Sportscar class is dominated by powerful "spec A" angle winder motors.
GT is dominated by powerful long can "spec A" inline motors because use of angle winders is restricted to "spec B" motors of 23k rpm and 280 gcm.
By fluke maybe, the Sioux motor (22krpm 280gcm) comes closer to the max spec-B permitted than any other motor I've found.
The GT lap record at LSC ( London Wood Green ) is held by the late John Secchi with an anglewinder black arrow ferrari GT italia so that is a formula I feel that I have to pursue.
I will write more on this model once we are all back up and racing.
Tool Tips
Tweezers are very useful for the small parts in this build.
1.5mm Allen Key (hex driver) is required.
In summary
As a racer, the car is yet to be tested but shows lots of promise.
For the home toy market, this car should be avoided because the build is too complex.
For shelf queen builders, a nice addition to your collection (if you have the time and patience to build the car to a high standard).
The build did take a lot of time but I enjoyed the challenge.
I'm hopeful that this car will be able to hold its own against other GT class cars at LSC but if it doesn't, upgrades will be coming to move it from GT class to SportsCar class. Lightweight interior, NSR King30 motor probably.
I can see the black bull needing new wing supports after its first impact so rubberised wing and supports will also be on the shopping list or fabrication list depending on availability.
Comments welcome :)
Alan
Given that Black Arrow is not a homologated manufacturer at my home club, what possessed me to engage in this notoriously difficult kit build?
"What do you want for Christmas dad?"
Hmm....
Which kit is going to challenge me during CoViD lockdown-2?
Which kit would be a useful weapon at other clubs and venues? Maybe wood tracks?
Which kit has presented BIG problems for other builder/racers?
Black Arrow are not typically available from UK suppliers.
SlotCarUnion supplied the kit
The car is a 1/32 scale representation of a Laborghini Murcielago.
The kit arrives in a cardboard box, no crystal display case or instructions included.
In the box are several zip lock bags containing all of the parts.
The component count is above 60 of which about 40 constitute the body components. A simple build this is not.
Very small parts are part of this build. There are even front and rear tow hoops which are indeed very small.
Job 1. Find the build instructions and lay the components out.
PDF available from black arrow's website for the build of the body only.
Split the components into "chassis" and "body" and began construction.
I immediately hit a known issue with the motor mount.
(Noted by an experienced builder, Alexis "in Greece" Gaitanis on another forum)
The sioux motor will not fit into the mount without bending the lower motor connector through 90 degrees.
I entertained the idea of drilling the motor mount but this is would have left its strength dangerously compromised.
A tip here is to use needle nose pliers to hold the connector in place while it is being bent. With pliers in place, no stress is put on the connector and a good 1mm radius can be achieved. The motor mount is chamfered at the point where the connector exists the motor end can so its not too hard to get this fitment right.
The motor mount is untypical in that the motor can move and be locked into position to optimise the gear mesh.
It might even be possible to use slightly differently sized crowns and pinions in this mount.
Suspension on a factory fit kit!
The blackbull is supplied with a 4 point suspension and black arrow Red springs.
For all other manufacturers , suspension is a post factory upgrade option.
The motor mount 4-point is not rectangular (not like a slot.IT mount) but is arranged as a front centre pivot, a rear centre pivot and a pair of outer pivots, left and right.
Apart from the motor issue, the chassis build was a pleasure.
Everything fitted. The guide is the best precision fit i have ever seen yet it swivels cleanly and self centres perfectly.
The factory fit braids look really good. No need to retrofit my usual NSR 0.2mm race braid
Building the body would only be a pleasure for a masochist.
I had made a decision to build the kit as per factory spec. No upgrades, no lightweight interior, no lexan crystalwork replacements etc so I diligently followed the PDF instructions.
Slavishly following the instructions left me with a roll cage in the (inevitable) small collection of small pieces left over.
The roll cage is not shown in the instructions. Pulling the interior out to to fit the roll cage invites refit problems.
The most challenging part of the build came from the small parts, especially the small photo etched grille work.
None of the etchwork fitted properly. The rear centre grille is shown as a complex 3d shape (in the instructions) but the actual item is dead flat. The instructions state "use flat plate to adapt photo etched parts" but there is no way to achieve this so the grille was installed as a flat piece.
The decalwork was somewhat problematic with some of the decals fracturing while being wetted for fitting.
The wind screen black surround decal fractured and had to be cut into a single sun strip.
The lightning strike decals are very skinny and required a lot of care to stop them breaking during fitment.
The "black arrow" decal for the rear wing is white which will not work on the white wing.
I painted the window wiper black because I found the white plastic didn't look right.
The car would look better if the white parts were all cast in black.
The wheel trims fitted without fettling.
The mirrors fitted easily.
The front winglets were difficult to fit (2 each side) because they are so small.
Crystalwork fitted well apart from the rear motor view triple hexagon window (supplied as 3 separate parts, not the single unit shown in the instructions) and required glue because the fitting pegs did not align to the windows.
On the rolling Road, the black bull pulls 8.4 metres per second at 12v, higher than factory fitted kits from other manufacturers.
The gearing is quite long for a factory fitted car.
Crown 30 teeth, 16 mm diameter
Pinion 13 teeth, 7.5 mm diameter
Wheel diameter in factory fitted tyres. 20mm
Ratio 2.3
Rollout is 27mm per rev.
The completed model (in factory trim) weighs in at 79g.
------------------
Was this car "Designed for a job" ?
This model is unique and contradictory in many respects.
The main contradiction is that this kit does not know whether it is a shelf queen display car or a "race it like you stole it" car.
There are sooooo many small and fragile components.
The rear wing supports will certainly not survive impact, making those on the Racer Sideways Huracan look very sturdy in comparison.
The Sioux motor is listed as zero downforce leading to the conclusion that this car was designed for a series where flux leakage is forbidden.
So, my best guess is that this car was designed to race in a Spanish "no downforce" formula, possibly against sports cars like the NSR Mosler (fitted with Spanish King motors?)
On paper, the black arrow would be a match for a Mosler of this specification.
--------------------
Did I get this car for "a job" ? Yes.
LSC Wood Green club has separate classes for "Sports Car" and "GT".
Sportscar class is dominated by powerful "spec A" angle winder motors.
GT is dominated by powerful long can "spec A" inline motors because use of angle winders is restricted to "spec B" motors of 23k rpm and 280 gcm.
By fluke maybe, the Sioux motor (22krpm 280gcm) comes closer to the max spec-B permitted than any other motor I've found.
The GT lap record at LSC ( London Wood Green ) is held by the late John Secchi with an anglewinder black arrow ferrari GT italia so that is a formula I feel that I have to pursue.
I will write more on this model once we are all back up and racing.
Tool Tips
Tweezers are very useful for the small parts in this build.
1.5mm Allen Key (hex driver) is required.
In summary
As a racer, the car is yet to be tested but shows lots of promise.
For the home toy market, this car should be avoided because the build is too complex.
For shelf queen builders, a nice addition to your collection (if you have the time and patience to build the car to a high standard).
The build did take a lot of time but I enjoyed the challenge.
I'm hopeful that this car will be able to hold its own against other GT class cars at LSC but if it doesn't, upgrades will be coming to move it from GT class to SportsCar class. Lightweight interior, NSR King30 motor probably.
I can see the black bull needing new wing supports after its first impact so rubberised wing and supports will also be on the shopping list or fabrication list depending on availability.
Comments welcome :)
Alan
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