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HSP 1/10 Storm 2WD Short Course Truck - Spur gear upgrade

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RC MAN

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Hi everyone

I have this HSP 1/10 Storm 2wd SCT that i am trying to upgrade and i am trying to find a spur gear that has less teeth and will fit it.
I do not have much knowledge on how you find a smaller spur gear that will fit your RC car, so it would be great if anyone could link a smaller spur gear or tell me what i need to know to look for one my self. 😀

Cheers
 
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WickedFog

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Hi everyone

I have this HSP 1/10 Storm 2wd SCT that i am trying to upgrade and i am trying to find a spur gear that has less teeth and will fit it.
I do not have much knowledge on how you find a smaller pinion gear that will fit your RC car, so it would be great if anyone could link a smaller pinion gear or tell me what i need to know to look for one my self. 😀

Cheers
You said spur gear then later said pinion. The pinion is on the motor shaft. The spur is the bigger one driven by the pinion. Which one are you looking for bud?

If it is the pinion, this should be the gear specs you need:
48dp pitch
Your motor shaft diameter should be 1/8" or 3.175mm.

Without knowing what size pinion you have, we can't recommend a smaller one. But you can count the teeth on yours and look here...
https://hobbiesdirect.com.au/parts/hsp/94607pro
 
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RC MAN

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You said spur gear then later said pinion. The pinion is on the motor shaft. The spur is the bigger one driven by the pinion. Which one are you looking for bud?

If it is the pinion, this should be the gear specs you need:
48dp pitch
Your motor shaft diameter should be 1/8" or 3.175mm.

Without knowing what size pinion you have, we can't recommend a smaller one. But you can count the teeth on yours and look here...
https://hobbiesdirect.com.au/parts/hsp/94607pro
Thanks for the response.
Sorry about the confusion when i said pinion gear i meant spur gear. I am too used to saying pinion gear, lol 😂
 

Greywolf74

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you're going to have to look up part numbers of other HSP, exceed, redcat, (whatever other brands are made by HSP) kits that have smaller tooth count spur gears and see if any of them match up with what yours looks like. For example if you compare a Traxxas Rustler spur gear with a revo spur gear the outter part of the gear looks a little different but the center part where it mounts looks exactly the same with the same 3 mounting holes. Once you find one that looks like it could work then all you can do is order it and pray it fits. If not rinse and repeat.

Rustler spur gear

41oz6Oz6pVL._AC_SX466_.jpg


REVO spur gear (different but same)

TRA3955__50456.1567111723.jpg
 

RC MAN

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you're going to have to look up part numbers of other HSP, exceed, redcat, (whatever other brands are made by HSP) kits that have smaller tooth count spur gears and see if any of them match up with what yours looks like. For example if you compare a Traxxas Rustler spur gear with a revo spur gear the outter part of the gear looks a little different but the center part where it mounts looks exactly the same with the same 3 mounting holes. Once you find one that looks like it could work then all you can do is order it and pray it fits. If not rinse and repeat.

Rustler spur gear

View attachment 132298

REVO spur gear (different but same)

View attachment 132299
you're going to have to look up part numbers of other HSP, exceed, redcat, (whatever other brands are made by HSP) kits that have smaller tooth count spur gears and see if any of them match up with what yours looks like. For example if you compare a Traxxas Rustler spur gear with a revo spur gear the outter part of the gear looks a little different but the center part where it mounts looks exactly the same with the same 3 mounting holes. Once you find one that looks like it could work then all you can do is order it and pray it fits. If not rinse and repeat.

Rustler spur gear

View attachment 132298

REVO spur gear (different but same)

View attachment 132299
Thanks so much for the advice 😀[Very helpful!]
I was unable to find something that would fit it so would you or anyone else know of a pinion gear that has more teeth than 45, is 48p and has a 5mm shaft diameter because i have been unsuccessful in finding one.

cheers,
 

Greywolf74

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Thanks so much for the advice 😀[Very helpful!]
I was unable to find something that would fit it so would you or anyone else know of a pinion gear that has more teeth than 45, is 48p and has a 5mm shaft diameter because i have been unsuccessful in finding one.

cheers,
If you're looking for a 48p 5mm bore pinion with more than 45T then good luck because IDK anyone who makes one that big. Theres only a couple of companies than even make 5mm bore 48P pinions and the biggest one I know of it 45T from Robinson Racing.
 

RC MAN

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If you're looking for a 48p 5mm bore pinion with more than 45T then good luck because IDK anyone who makes one that big. Theres only a couple of companies than even make 5mm bore 48P pinions and the biggest one I know of it 45T from Robinson Racing.
Thanks for the response.

I was looking for a smaller spur great because i couldn’t find any bigger pinions out there and you saying that YOU have never come across one your self probably conforms my theory about there isn’t a bigger pinion🤔. But would you or anybody else know of a spur gear that has less teeth 81 and looks to have a hexagonal slipper clutch groove on the side of it😀. Any help would be great!
 

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Are you just trying to get more speed out of it? Can you not just upgrade the motor? Going with a taller tire would have the same effect as well.
 
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Greywolf74

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You can also try and find a 32P or Mod1 spur that will work too and then you'll have more options for pinions. Like Fog said too if your just looking for more speed try a higher KV motor. What motor are you running now cuz 45T pinion and 81T spur is already a really short 1.8:1 gear ratio. What is the kv of your current motor and what kind of temps is it running at?
 

RC MAN

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Thanks for the Info. I think i will scrap the idea of trying to go any faster but on a totally unrelated note, what do you guys think is the best gear ratio for just general bashing on a 1/10th scale rig. [general bashing=offroad and on road]
 

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Thanks for the Info. I think i will scrap the idea of trying to go any faster but on a totally unrelated note, what do you guys think is the best gear ratio for just general bashing on a 1/10th scale rig. [general bashing=offroad and on road]
As short of a ratio as you can make it without overheating the motor unless you like doing a lot of wheelies then you may need to gear taller
 

RC MAN

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As short of a ratio as you can make it without overheating the motor unless you like doing a lot of wheelies then you may need to gear taller
Thanks for the great advise!
Very helpful!
Would another good way to determine your best gear ratio to be that to get your vehicle to go as fast as it can go without parachuting or anything else like that and then keep gearing down until its maximum speed goes down. Because if you have geared your car to go IN THEORY 130mph for example, it might never reach that top speed because of wind resistance, parachuting and so on. So if you measure its top speed, say 70mph when you have geared it to go to 130mph, would you just gear it down so you get the benefits of more run time, less strain on things, less heat, less ripple voltage and so on and still get that top speed of 70mph?🤔
 

Greywolf74

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Thanks for the great advise!
Very helpful!
Would another good way to determine your best gear ratio to be that to get your vehicle to go as fast as it can go without parachuting or anything else like that and then keep gearing down until its maximum speed goes down. Because if you have geared your car to go IN THEORY 130mph for example, it might never reach that top speed because of wind resistance, parachuting and so on. So if you measure its top speed, say 70mph when you have geared it to go to 130mph, would you just gear it down so you get the benefits of more run time, less strain on things, less heat, less ripple voltage and so on and still get that top speed of 70mph?🤔
You can gear it however you want to, the important thing is not to overheat the motor and burn it up. I dont like to see my motors going above about 170-175F
 

RC MAN

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You can gear it however you want to, the important thing is not to overheat the motor and burn it up. I dont like to see my motors going above about 170-175F
Yeah i don't like mine going above 170F as well. 😀

Also completely unrelated to this but...

Would you use that mobil 1 synthetic grease in the diff for general bashing? Have you tried LUCAS OIL white lithium grease before because that is supposed to be really good as well but do you think it is better than the mobil 1 synthetic grease and would it be safe on a plastic diff? Also would you put that grease or really heavy diff oil in a 2wd 1/10th scale set up to increase traction and if so what cst of oil? Also what is the thickness of grease in cst? 😀


[Sorry for asking a lot of questions]
 

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WickedFog

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Yeah i don't like mine going above 170F as well. 😀

Also completely unrelated to this but...

Would you use that mobil 1 synthetic grease in the diff for general bashing? Have you tried LUCAS OIL white lithium grease before because that is supposed to be really good as well but do you think it is better than the mobil 1 synthetic grease and would it be safe on a plastic diff? Also would you put that grease or really heavy diff oil in a 2wd 1/10th scale set up to increase traction and if so what cst of oil? Also what is the thickness of grease in cst? 😀


[Sorry for asking a lot of questions]
We discussed this the other day. The red Mobil1 grease is what a few people here are using. The Lucas white lithium is actually not safe for plastics, but I have seen people using it in plastic housings. I'd go with the Mobil1.
 

Greywolf74

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Would you use that mobil 1 synthetic grease in the diff for general bashing?
Yes, I use it in quite a few of my bashers. I even use it in the transmission case of my 100+MPH Rustler.
Have you tried LUCAS OIL white lithium grease before because that is supposed to be really good as well but do you think it is better than the mobil 1 synthetic grease and would it be safe on a plastic diff?
I would not use white lithium grease, I've read its bad for plastic.
Also would you put that grease or really heavy diff oil in a 2wd 1/10th scale set up to increase traction and if so what cst of oil?
When you say increased traction are you talking about limiting wheel spin? You would do that with the slipper clutch. If you're talking about something like a limited slip differential then it depends on if the transmission has a gear diff or a ball diff inside of it. If its a gear diff you can fill the diff itself with fluid and then use grease in the rest of the transmission. If its a ball diff then I couldnt tell ya cuz I'm not very familiar with ball diffs.
Also what is the thickness of grease in cst? 😀
No clue, but when you use grease you dont fill the diff/transmission completely otherwise theres to much resistance and it will build heat. You fill it up enough so that it fills all the nooks and crannies and has just enough so that the diff gears are constantly picking up a little of it and spreading it around to the rest of the gears so if its filled with grease properly its not really adding much resistance to the gears inside like fliiling it with fluid will.
[Sorry for asking a lot of questions]
No worries. :)
 
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RC MAN

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Yes, I use it in quite a few of my bashers. I even use it in the transmission case of my 100+MPH Rustler.

I would not use white lithium grease, I've read its bad for plastic.

When you say increased traction are you talking about limiting wheel spin? You would do that with the slipper clutch. If you're talking about something like a limited slip differential then it depends on if the transmission has a gear diff or a ball diff inside of it. If its a gear diff you can fill the diff itself with fluid and then use grease in the rest of the transmission. If its a ball diff then I couldnt tell ya cuz I'm not very familiar with ball diffs.

No clue, but when you use grease you dont fill the diff/transmission completely otherwise theres to much resistance and it will build heat. You fill it up enough so that it fills all the nooks and crannies and has just enough so that the diff gears are constantly picking up a little of it and spreading it around to the rest of the gears so if its filled with grease properly its not really adding much resistance to the gears inside like fliiling it with fluid will.

No worries. :)
Thanks for the response, I will defiantly take the advise and go with the Mobil 1 grease. 😀

Would you recommend a certain CST of diff oil for bashing in a 1/10th 2wd sct?

So is this how i should replace my diffs fluid, buy mobil 1 grease, get whatever diff oil i should get, fill up my diff with the oil and then use the grease around the diff or do i put the grease in the diff?

I have never changed a diffs fluid before so i would be very helpful if you could tell me what to do with the oil and the grease. 😀

Thanks
We discussed this the other day. The red Mobil1 grease is what a few people here are using. The Lucas white lithium is actually not safe for plastics, but I have seen people using it in plastic housings. I'd go with the Mobil1.
Thanks for the advise, very helpful 😀
 

Greywolf74

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Thanks for the response, I will defiantly take the advise and go with the Mobil 1 grease. 😀

Would you recommend a certain CST of diff oil for bashing in a 1/10th 2wd sct?

So is this how i should replace my diffs fluid, buy mobil 1 grease, get whatever diff oil i should get, fill up my diff with the oil and then use the grease around the diff or do i put the grease in the diff?

I have never changed a diffs fluid before so i would be very helpful if you could tell me what to do with the oil and the grease. 😀
IDK what kind of kit you have but below is a cutaway pic of a traxxas Rustler/Slash/Stampede 2WD transmission and most 2WD transmissions are pretty similar to this. The largest gear at the top is yopur input shaft which holds your spur gear and slipper clutch on the outside. The smallest gear in the middle is your idler gear and the middle sized gear at the bottom with the white plastic side on it is your differential that sits on your output shaft.

magnum_272_tranny_cutaway.jpg


The diffs in these types of 2wd transmissions can be gear diffs or ball diffs. Typically they are going to be gear diffs like these. Also typically these types of diffs arent sealed so you dont want to put oil in them so use grease unless you want to mod the diff to make it sealed so you can run oil. I've never done it myself but there are videos out there like THIS one that show you how to mod it. So once you get the diff squared away with either grease or oil then put all the gears and shafts back into the transmission case and then use grease inside the transmission case itself.

As I stated above, when you use grease you dont fill the diff/transmission completely otherwise theres to much resistance and it will build heat. You fill it up enough so that it fills all the nooks and crannies and has just enough so that the diff gears are constantly picking up a little of it and spreading it around to the rest of the gears so if its filled with grease properly its not really adding much resistance to the gears inside, its just keeping it lubed.

As for what weight oil to use if you use oil? Well, this is a post from another forum that is talking about the 2WD Slash in particular but would probably be fairly applicable to any of the traxxas 2wd rigs. If you dont have a traxxas then you just have to experiment to see what works best for your kit or do a bit of googling online to see what others are running for your specific kit. Diff oil weight is really a personal preference and part of tuning your rig.

The Traxxas gear design requires a heavier fluid to be effective than other design diffs. I am running 100k on mine for a very tricky low grip outdoor track. I just started running a high bite tight indoor course and believe the diff is too thick for that course. I will be dropping to 50k or so at my next rebuild. Anything much less than 10-15k in the slash rear end is about like the grease that was in it stock!

"Heavier diff fluids will hurt the truck turn in on corner entry and overall make it push some. But they improve forward traction on a low grip surface. Under power on corner exit, heavier fluid tends to make the rear want to step out slightly as traction brakes, but it is more of a controllable drift. Lighter diff fluid will improve turn in on corner entry and allow the truck to rotate better. It does not apply power as evenly under acceleration and can allow power to go to the unloaded tire and reduce acceleration. This can result in slightly less overall forward bite. It can also allow the truck to "diff out" when turning under power. When the truck "diffs out" the weight transfers to the outside tires and unloads the inside tire. This causes the outside tire to lose power and the inside tire to spin up. This can make the truck spin out or roll over very aggressively at times. The truck rolls because the front tires gain traction as the truck loses forward bite and the outside takes more side bite as they slow down. Watch a full sized SC truck run....they cannot lift in the corner, if they do...well...same thing.

So, lots of words to say diff fluid is a preference to driving style, truck type, and track type. I like to sling my truck in and drift a bit, so heavier fluids for me. As I gain experience and improve throttle control, I am finding a need to reduce diff fluid weight so I can roll the corner more."

If you want to learn more about how diff oil weight affects your rig then check this out. In the case of a 2wd then you're only gonna have a rear diff.

Diff oil weight effects.JPG
 

RC MAN

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IDK what kind of kit you have but below is a cutaway pic of a traxxas Rustler/Slash/Stampede 2WD transmission and most 2WD transmissions are pretty similar to this. The largest gear at the top is yopur input shaft which holds your spur gear and slipper clutch on the outside. The smallest gear in the middle is your idler gear and the middle sized gear at the bottom with the white plastic side on it is your differential that sits on your output shaft.

View attachment 132606

The diffs in these types of 2wd transmissions can be gear diffs or ball diffs. Typically they are going to be gear diffs like these. Also typically these types of diffs arent sealed so you dont want to put oil in them so use grease unless you want to mod the diff to make it sealed so you can run oil. I've never done it myself but there are videos out there like THIS one that show you how to mod it. So once you get the diff squared away with either grease or oil then put all the gears and shafts back into the transmission case and then use grease inside the transmission case itself.

As I stated above, when you use grease you dont fill the diff/transmission completely otherwise theres to much resistance and it will build heat. You fill it up enough so that it fills all the nooks and crannies and has just enough so that the diff gears are constantly picking up a little of it and spreading it around to the rest of the gears so if its filled with grease properly its not really adding much resistance to the gears inside, its just keeping it lubed.

As for what weight oil to use if you use oil? Well, this is a post from another forum that is talking about the 2WD Slash in particular but would probably be fairly applicable to any of the traxxas 2wd rigs. If you dont have a traxxas then you just have to experiment to see what works best for your kit or do a bit of googling online to see what others are running for your specific kit. Diff oil weight is really a personal preference and part of tuning your rig.

The Traxxas gear design requires a heavier fluid to be effective than other design diffs. I am running 100k on mine for a very tricky low grip outdoor track. I just started running a high bite tight indoor course and believe the diff is too thick for that course. I will be dropping to 50k or so at my next rebuild. Anything much less than 10-15k in the slash rear end is about like the grease that was in it stock!

"Heavier diff fluids will hurt the truck turn in on corner entry and overall make it push some. But they improve forward traction on a low grip surface. Under power on corner exit, heavier fluid tends to make the rear want to step out slightly as traction brakes, but it is more of a controllable drift. Lighter diff fluid will improve turn in on corner entry and allow the truck to rotate better. It does not apply power as evenly under acceleration and can allow power to go to the unloaded tire and reduce acceleration. This can result in slightly less overall forward bite. It can also allow the truck to "diff out" when turning under power. When the truck "diffs out" the weight transfers to the outside tires and unloads the inside tire. This causes the outside tire to lose power and the inside tire to spin up. This can make the truck spin out or roll over very aggressively at times. The truck rolls because the front tires gain traction as the truck loses forward bite and the outside takes more side bite as they slow down. Watch a full sized SC truck run....they cannot lift in the corner, if they do...well...same thing.

So, lots of words to say diff fluid is a preference to driving style, truck type, and track type. I like to sling my truck in and drift a bit, so heavier fluids for me. As I gain experience and improve throttle control, I am finding a need to reduce diff fluid weight so I can roll the corner more."

If you want to learn more about how diff oil weight affects your rig then check this out. In the case of a 2wd then you're only gonna have a rear diff.

View attachment 132605
Thanks for the advice!
I really appreciate It 😀
 
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