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Azkuma

Hotshot Re Issue

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Just a question to all the speed kings out there as I'm just curious how much a Hotshot can actually handle. I know a Super Stock BZ should be sufficient but I've seen Hotshots with brushless setups so I'm wondering how low (number of turns) can you go for a motor in a re issue Hotshot?

Is a Dynatech 01R/02H too much to handle?

What about a Super Modified 11T?

Who is running with a 10T brushless, or even lower?

How long before the gears melt and you need to rebuild the whole car?

Of course using any of these motors is precluded by the fact that full ball races are being used all round. :)

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The key to getting long life from the Tamiya gearboxes is to throw the kit supplied butter soft aluminium pinion in the nearest bin and fit a steel pinion.

As for what the Hotshot can handle is down to the FDR. Matching the Kv of the motor to the gearing available is the key to a brushless system that runs at comfortable temperatures and is 'gentle' on the battery packs. I wouldn't go much higher Kv than 4600Kv in it myself, but I've seen more and I've seen less.

Brushless is more about trouble and maintainence free running than it is about speed. Brushless will continue to perform without any drop off in power run after run after run, unlike a brushed motor which needs it's brushes replaced and coms cut to maintain the 'out of the box' performance.

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With all my shots i have found the best brushed motor to be a 19t Trinity komondo or chamelon. After lots of testing with all winds down to 11t found the gearing was more suited for the 19t. Funny as the Super Shot Technipower was close to a 19t was using a 13 and 15t pinion.

As TA Mark said use a steel pinion.

The gearing in the shots is quite tall so will suit a brushles and my Big Wig will soon be fitted with a 10.5 0r 13.5. brushless.. In Testing a 13.5 is very close to a 19t brushed.

Use Tamiya ceramic grease on all the plastic gears just a little and some mollybourne grease on the metal star gears to help wear.

Have seen a Boomerang with a 3cell lipo and Zrun 9t on here some where and was just ballistic.

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Thanks for the replies guys.

I'll definitely fit a steel pinion if running anything more than a 19T and as for grease I've been using Tamiya's Molybdenum grease but not sure if that is widely used by anyone but it is what they recommend on their gears.

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I used to use a 13 double brushed motor in an original boomerang with a 13t pinion, but it did wear out the dogbones and axles pretty quickly. Of course, if you hit anything at full throttle it was extremely painful :o

PS, does anyone know if anyone makes a ball diff or 1 way for the hotshot ????

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I think Thorp made ball diffs for the Hot Shot back in the day, but I'm not sure. In any case it would be rare/expensive nowadays.

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Hi

I have the very similar Tamiya re release Boomerang with an Ezi run 9 turn and coincidently enough I spent yesterday evening pulling apart the front gearbox to find out the source of some vibration in the front wheels. I have replaced the front drive cups but not sure if this has fixed the problem. I also have uni joints on the front from a Thundershot which don't appear to have bent shafts so still trying to figure out what the problem is. Interestingly the front gearboxes gears are still in suprisingly good condition; I was think I would have to replace the gears after 6 months of use but they are Ok for now.

The 9 turn Ezi Run is running a 13 tooth pinion as 15 tooth is too fast for my driving ability. I have also programmed the Ezi run to have the timing retarded and the punch off the line is very soft with hard braking. The hard braking is what is wearing the drive cups on the rear of the slots and I suspect this is what is causing the vibration. These cups are made from black metal, does this wear quicker than the chrome/silver coloured axle drive cups? The Thundershot front uni joints appear not to be sloppy so I don't think this is the problem.

Anyway I find the Ezi run 9 turn is a bit overpowered but you can always gear it down and programme the esc to minimise punishment on the Hotshot drivetrain or try a 13 turn Ezi run. Bear in mind impact speeds are higher with a brushless 9 turn if your Hotshot has an accident so make sure you have a good supply of spare parts or access to spare parts from the web or your local hobby store etc.

Interestingly I have heard the lates Hotshot its are made in the Phillipnes. Is this correct/has anyone seen the non Japanese made rerelease Hotshot kits?

Thankyou

Ian

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The black drive cups are hardened ( Heat treated)

The silver ones are just mild steel which are softer.

I balance all my tires/rims and never have any vibration. A bent shaft doesn't add to much in vibration.

Next time you have any vibration take the wheels off and see how much there is under full throttle.

As for ball diffs i have never seen any for hot shots but have seen them adapted from a fox ball diff ( Panoria or Throp.)

All my Hot Shots re re are from Japan and have herd they are now discontuned. I have built a Grasshopper from the Phillipeanse and was not as good in fit as my other Tamiya kits.

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hey mad racer

that cameleon is good motor

i doubt u would want any more on a hotshot

these older small rc cars are so light and at hi speed any bumps and the thing cart wheels

on tar my hotshot goes pretty good but on a track or short grass its ok but dont try to turn sharply

and over jumps it cartwheels eheheh ive bent an axle and its the steel alloy coloured ones o as mad said they r not as strong

i lost an axle the other day whiel friend was driving it and it was in 2wd mode and since less load on motor it cooked the bushes

pulled motor apart and lightly sanded armature and bushes with wifes nail file and buffer so it al works again not sure if it has ful speed again

if nto ill solder new bushes as the armature was spotless

anyway with so much grunt in a small car u need very good driving skill if u ever take it to a proper track

no traction off the mark and oversteer as u slow down coming into corners

i got sick of breaking my two hotshots so bought a revo

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Hi

I have the very similar Tamiya re release Boomerang with an Ezi run 9 turn and coincidently enough I spent yesterday evening pulling apart the front gearbox to find out the source of some vibration in the front wheels. I have replaced the front drive cups but not sure if this has fixed the problem. I also have uni joints on the front from a Thundershot which don't appear to have bent shafts so still trying to figure out what the problem is. Interestingly the front gearboxes gears are still in suprisingly good condition; I was think I would have to replace the gears after 6 months of use but they are Ok for now.

The 9 turn Ezi Run is running a 13 tooth pinion as 15 tooth is too fast for my driving ability. I have also programmed the Ezi run to have the timing retarded and the punch off the line is very soft with hard braking. The hard braking is what is wearing the drive cups on the rear of the slots and I suspect this is what is causing the vibration. These cups are made from black metal, does this wear quicker than the chrome/silver coloured axle drive cups? The Thundershot front uni joints appear not to be sloppy so I don't think this is the problem.

Anyway I find the Ezi run 9 turn is a bit overpowered but you can always gear it down and programme the esc to minimise punishment on the Hotshot drivetrain or try a 13 turn Ezi run. Bear in mind impact speeds are higher with a brushless 9 turn if your Hotshot has an accident so make sure you have a good supply of spare parts or access to spare parts from the web or your local hobby store etc.

Interestingly I have heard the lates Hotshot its are made in the Phillipnes. Is this correct/has anyone seen the non Japanese made rerelease Hotshot kits?

Thankyou

Ian

Hi Ian,

Your problem with the vibration is the thundershot drive shafts. They're too long to fit in the front of the hotshot. Hotshot \ boomerang front drive shafts are shorter than the rear. Tamiya made thundershot shafts the same length front and rear, but standardised on the length of the hotshot rear drive shaft. On the plus side, they fit perfectly in the rear of the boomerang.

Best wishes,

Martin

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Hi Ian,

Your problem with the vibration is the thundershot drive shafts. They're too long to fit in the front of the hotshot. Hotshot \ boomerang front drive shafts are shorter than the rear. Tamiya made thundershot shafts the same length front and rear, but standardised on the length of the hotshot rear drive shaft. On the plus side, they fit perfectly in the rear of the boomerang.

Best wishes,

Martin

Hi Martin

Thanks for you advice. I have swapped the Thundershot uni driveshafts for the Tamiya DF-02 uni driveshafts on the front and it appears to have fixed the vibration. I will put the Thundershot driveshafts in the back of the Boomerang re release when I get time and give it a test run.

Ian

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