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  1. #1
    RC Qualifier Flux Capacitor's Avatar
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    Testing a new motor pinion idea.

    So I basically have tried every possible trick I know for mounting motor pinions and this X-Maxx keeps on laughing at every thing I have thrown at it to stop the pinion set screw from backing out. My latest attempt was the divot trick on the motor shaft to stop the pinion from walking.

    Although it did work, it still did not stop the set screw from backing out. When it did back out with the divot on the shaft, it started to gull out the divot on the shaft and left me with little choice but to try this one last attempt at finding a solution.

    Here I will outline what I did and I sure hope to heck it works.

    First I drilled the motor shaft starting with a 5/64th drill bit and then final drilled the hole with a 3/32nd bit. Since I already had a pilot divot on the flat side of the shaft, it made it so the drill bits didn't walk all over the shaft when drilling. I highly suggest doing this with a drill press; but I did it free hand and it worked because I have steady hands and many, many years of experience drilling hard metals.



    As you can see, there is plenty of meat left on both sides of the hole and should not present a problem, but only testing it will let me know if this gamble was worth it.

    Next, I had to find a drill shank with the diameter of my 3/32nd motor shaft hole and cut it to a length of 11mm.





    Then I had to do the tricky free hand part of drilling new pinion holes in my pinion. Again, I highly suggest using a drill press when drilling rounded surfaces or you run the risk of misalignment between your starting hole and exit hole.



    Here, the pinion is being test fitted for alignment and this was the part where I was holding my breath because this is the make or break moment for finding out if my hands were truly steady. The pin is half way in here:



    I knew I could do it! The pin slid all the way in, and there was zero rotational slop between the motor shaft and pinion.



    It was flush on both sides:





    Now I had to secure the pin with some industrial tube heat shrink:



    And then finally I had to check the alignment of the pinion with the spur and all looked good!



    Now I have to get the X-Maxx back together and give this a try. If this doesn't work, it will give me an excuse to move on to another motor and another chapter of upgrades!
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  2. #2
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    The pinion has been a right pain for me. I have tried so many different thread lockers but as soon as the motor gets a bit too warm, I get the buzzing sound of a loose pinion even when it’s been tightened by the hulk Always ended up taking an align multi tool to the field with me to put a pinion back on.

    Your solution looks ace! That hole in the shaft looks factory. You did an awesome job of drilling it straight.

    I’d be interested to see how this holds up and look forward to some updates


    To the mooooon!

    Traxxas has a strict language policy. A word filter operates to change inappropriate words to *s. When you see these in your post, you MUST edit them out. -ksb51rl
    Last edited by ksb51rl; 11-10-2020 at 05:29 PM.
    To the Moon 🌙

  3. #3
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by hallamnet View Post
    The pinion has been a right pain for me. I have tried so many different thread lockers but as soon as the motor gets a bit too warm, I get the buzzing sound of a loose pinion even when it’s been tightened by the hulk Always ended up taking an align multi tool to the field with me to put a pinion back on.

    Your solution looks ace! That hole in the shaft looks factory. You did an awesome job of drilling it straight.

    I’d be interested to see how this holds up and look forward to some updates


    To the mooooon!
    Thanks!

    I'm just concerned about the torsional strength of the shaft being compromised by the hole I drilled. Then again, this very same idea is used inside the spur internals (Cush drive assembly) and I haven't had that fail on me yet. I had done this before on a 6S motor and it worked well. So well in fact, that the idea outlasted the pinion. I actually wore the pinion down before any rotational slop ever existed between the pinion and shaft.

    Time will tell if this can stand up to 8S.
    Last edited by ksb51rl; 11-10-2020 at 05:27 PM. Reason: Updated.
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  4. #4
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    Quote Originally Posted by Flux Capacitor View Post
    So I basically have tried every possible trick I know for mounting motor pinions and this X-Maxx keeps on laughing at every thing I have thrown at it to stop the pinion set screw from backing out. My latest attempt was the divot trick on the motor shaft to stop the pinion from walking.

    Although it did work, it still did not stop the set screw from backing out. When it did back out with the divot on the shaft, it started to gull out the divot on the shaft and left me with little choice but to try this one last attempt at finding a solution.

    Here I will outline what I did and I sure hope to heck it works.

    First I drilled the motor shaft starting with a 5/64th drill bit and then final drilled the hole with a 3/32nd bit. Since I already had a pilot divot on the flat side of the shaft, it made it so the drill bits didn't walk all over the shaft when drilling. I highly suggest doing this with a drill press; but I did it free hand and it worked because I have steady hands and many, many years of experience drilling hard metals.



    As you can see, there is plenty of meat left on both sides of the hole and should not present a problem, but only testing it will let me know if this gamble was worth it.

    Next, I had to find a drill shank with the diameter of my 3/32nd motor shaft hole and cut it to a length of 11mm.





    Then I had to do the tricky free hand part of drilling new pinion holes in my pinion. Again, I highly suggest using a drill press when drilling rounded surfaces or you run the risk of misalignment between your starting hole and exit hole.



    Here, the pinion is being test fitted for alignment and this was the part where I was holding my breath because this is the make or break moment for finding out if my hands were truly steady. The pin is half way in here:



    I knew I could do it! The pin slid all the way in, and there was zero rotational slop between the motor shaft and pinion.



    It was flush on both sides:





    Now I had to secure the pin with some industrial tube heat shrink:



    And then finally I had to check the alignment of the pinion with the spur and all looked good!



    Now I have to get the X-Maxx back together and give this a try. If this doesn't work, it will give me an excuse to move on to another motor and another chapter of upgrades!
    Very interesting idea, mate, my congrats.

  5. #5
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    i've had the opposite. pinion never moved for me but the spur gear exploded on me the first time and the second one i lost a few teeth. but that was with stock spurs..

    i thought about doing this but using the grub screws with the shaft like this
    https://rcbitz.com/hardware-nuts-bol...86-driveshaft/

  6. #6
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    Quote Originally Posted by 95blackz26 View Post
    i've had the opposite. pinion never moved for me but the spur gear exploded on me the first time and the second one i lost a few teeth. but that was with stock spurs..

    i thought about doing this but using the grub screws with the shaft like this
    https://rcbitz.com/hardware-nuts-bol...86-driveshaft/
    Very clever.

  7. #7
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by Juanmacine View Post
    Very interesting idea, mate, my congrats.
    Thanks Juanmacine!

    I will test this out and report back if it works or I end up picking up pieces because it failed. I just don't understand why Traxxas made such an outstanding truck and decided to wimp out on a secure pinion solution. The motor generates too much heat for existing thread lockers on the market to securely mount the tiny mounting screw. Take into account also that the pinion hole is not "D" shaped and you have the perfect recipe for continually failing pinions/spurs.

    On another brand, the pinion is secured in three ways. The pinion hole is "D" shaped, it has a set screw and it has an e-clip to stop the pinion from walking.

    Sometimes, we just have to take matters into our own hands and accept the fact that certain things are made a certain way in order to keep the profits flowing. Honestly, I think it is ignorant to pass a truck off of this magnitude to customers knowing that the main propulsion system has a systemic flaw that allows parts to be destroyed on a regular basis so the revenue keeps flowing in.

    In any case, I fixed it and it should be the solution I am looking for. I did this so I don't have to buy another motor and mount and it is interesting how creative I can get when I become irritated enough over incompetent designs; especially when the designs are designed to keep raking in money as if to say that paying almost a grand for the truck should have taken care of that part from the get go.

    Oh well, if they would have designed it right, they wouldn't have to worry about future profits and people would say "Hey, you know what, they designed this truck right!" and passing that on by word of mouth would get them further than intentionally designing flaws into something to get more money."

    Quote Originally Posted by 95blackz26 View Post
    i've had the opposite. pinion never moved for me but the spur gear exploded on me the first time and the second one i lost a few teeth. but that was with stock spurs..

    i thought about doing this but using the grub screws with the shaft like this
    https://rcbitz.com/hardware-nuts-bol...86-driveshaft/
    I almost did that; but then I thought about what I was trying to get away from in the first place. My solution eliminates the possibility of anything backing out. The idea was to work off of the "captured" idea and eliminate any threading parts that could work loose.
    Last edited by Flux Capacitor; 11-10-2020 at 05:58 PM. Reason: Updated.
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  8. #8
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    Knowing you, I'm sure you tried RED Loctite, and if your motor is getting so hot that it softens your RED Loctite; your motor is getting way to hot. It takes a lot of heat to soften RED Loctite. You did a terrific job with your fix, but don't be surprised if down the road you need a better motor that doesn't get as hot as the one you have now.
    Life's to short to be a sour puss.

  9. #9
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by ReglarGuy View Post
    Knowing you, I'm sure you tried RED Loctite, and if your motor is getting so hot that it softens your RED Loctite; your motor is getting way to hot.
    Now here is the curious thing about what you are pointing out. Red LoctiteŽ 272 is claimed to be good to a 450°F point of heat resistance before thermal breakdown. There is no way my motor is reaching any where near that threshold of heat dissipation. Irreversible damage to the motors components begins at roughly 210°F~250°F or higher or so I've read.

    Thermal motor protection kicks in way before those temperatures are ever reached. So, by logical standards, either you're telling me: (1) My motor thermal protection isn't working or (2) Red LoctiteŽ 272 is making inaccurate/false claims in regards to actual ASTM results.

    I can without a doubt tell you for sure it isn't number one listed above; however since Henkel bought/acquired LoctiteŽ (German Fortune 500 Company) the product has never been the same.

    So in conclusion by deductive reasoning and numerous reports in the X-Maxx forum that most thread lockers are failing to secure the pinions on a majority of X-Maxx's, I'm left leaning towards the 2nd point I made above.

    It isn't entirely the LoctiteŽ that is at fault here either. Improper preparation of the surfaces for LoctiteŽ application is the number one cause of the product not performing correctly also. I've been at this far too long to get into detailed discussions about my Naval years where the only solution we had to beat vibration and heat in Designation 7 Main Propulsion was to use lock wire or the "captured" procedure.

    Unfortunately, on an application such as a set screw this small on a pinion of a high rotation motor of this size, lock wire is just not a practical solution due to the lack of securing surface (round smooth surface) and mounting points to twist tie the wire off. For lock wire to be effective and practical in its application, more than one mounting point is recommended but not always entirely necessary.
    Last edited by Flux Capacitor; 11-11-2020 at 09:39 AM. Reason: Updated.
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  10. #10
    RC Qualifier Flux Capacitor's Avatar
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    This Paid Off and Man do I have the Proof!

    O.K.-----So I decided to put this new pinion idea to the most brutal test that can be thrown at it. Keep in mind, my rig with the Max5 and Badlands weighs 24 pounds clean without the two 4S batteries. With the two 6700mah Traxxas batteries it weighs just a smidgen under 26 pounds.

    I took it mud running today:



    Weighed it after I took the batteries out and it came to about 37 pounds:



    So essentially, I picked up almost twelve pounds of passenger mud of which most was stuck to the underside of the rig and in the inner wheel wells as well as stuck in the knobby treads of the Badlands. Some of course was stuck to the rear arms as well.

    In fairness, the block of wood that I rested it on to weigh it, comes in around a half of a pound:



    So eleven and a half pounds of passenger mud plus the two Traxxas 6700mah batteries I calculate that the pinion capture idea was toting around 36~37 pounds of pure muddy X-Maxx muscle and not even thinking twice about it!

    It sure is nice not having to worry about my pinion set screw anymore and the only time I think (no actually, now I'm sure) I'm going to have to even worry about my pinion is when I want to change the tooth count.

    So there is the follow up report fellas and it seems as though not only can this idea stand up to 8S; but it appears that it would work on 40 pound rigs with no problem.

    I love it when my ideas work, so eat your heart out Traxxas engineers!
    Last edited by Flux Capacitor; 11-12-2020 at 06:52 PM. Reason: Updated.
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  11. #11
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    Quote Originally Posted by Flux Capacitor View Post
    O.K.-----So I decided to put this new pinion idea to the most brutal test that can be thrown at it. Keep in mind, my rig with the Max5 and Badlands weighs 24 pounds clean without the two 4S batteries. With the two 6700mah Traxxas batteries it weighs just a smidgen under 26 pounds.

    I took it mud running today:



    Weighed it after I took the batteries out and it came to about 37 pounds:



    So essentially, I picked up almost twelve pounds of passenger mud of which most was stuck to the underside of the rig and in the inner wheel wells as well as stuck in the knobby treads of the Badlands. Some of course was stuck to the rear arms as well.

    In fairness, the block of wood that I rested it on to weigh it, comes in around a half of a pound:



    So eleven and a half pounds of passenger mud plus the two Traxxas 6700mah batteries I calculate that the pinion capture idea was toting around 36~37 pounds of pure muddy X-Maxx muscle and not even thinking twice about it!

    It sure is nice not having to worry about my pinion set screw anymore and the only time I think (no actually, now I'm sure) I'm going to have to even worry about my pinion is when I want to change the tooth count.

    So there is the follow up report fellas and it seems as though not only can this idea stand up to 8S; but it appears that it would work on 40 pound rigs with no problem.

    I love it when my ideas work, so eat your heart out Traxxas engineers!
    Like very much this vintage weighing machine.

  12. #12
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by Juanmacine View Post
    Like very much this vintage weighing machine.
    I figured someone would get a kick out of that high-tech weight scale! I actually tested its accuracy against a digital scale and 50 years later, my good old Borg is still right on the money.

    It actually has a trim knob to center to zero because the spring tension does wear after a while.
    Last edited by Flux Capacitor; 11-13-2020 at 01:25 PM. Reason: Updated.
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  13. #13
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    Quote Originally Posted by Flux Capacitor View Post
    I figured someone would get a kick out of that high-tech weight scale! I actually tested its accuracy against a digital scale and 50 years later, my good old Borg is still right on the money.

    It actually has a trim knob to center to zero because the spring tension does wear after a while.
    Love that vintage objects.

  14. #14
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    Quote Originally Posted by Flux Capacitor View Post


    I almost did that; but then I thought about what I was trying to get away from in the first place. My solution eliminates the possibility of anything backing out. The idea was to work off of the "captured" idea and eliminate any threading parts that could work loose.
    RED locitite man. once i got a good coat of it on the threads on that belt drive setup i was running the grub screws didn't budge i even had to use a torch lighter to throw some heat at it to get one of the screws out.
    Last edited by Double G; 11-13-2020 at 06:46 PM. Reason: language

  15. #15
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    Awesome fix for the pinion. If it doesn't hold up because the shaft on the motor breaks, it's likely due to the added weight.
    I'm really shocked at how much weight you gained in a bashing session. I never thought to weigh ours but with the wet season upon us I'm going to check ours on the next run.
    Nice to see your getting lots of run time. Did you go back to running a Max 5?

  16. #16
    RC Champion grizzly03's Avatar
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    I guess you found a way to measure fun! I never thought that much fun could be collected, LoL!

  17. #17
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    Quote Originally Posted by Flux Capacitor View Post
    On another brand, the pinion is secured in three ways. The pinion hole is "D" shaped, it has a set screw and it has an e-clip to stop the pinion from walking.
    I saw these pinion gears and wondered if they may be an easy fix for the X-Maxx.
    I think the motor shaft diameters match, so a gentle grind on the motor shaft to put a flat spot on it should mean the D shape pinion would fit.
    I'm not sure it would help and I've not tried it, but it makes a lot of sense in my head.

  18. #18
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by Rain Dawg View Post
    Awesome fix for the pinion. If it doesn't hold up because the shaft on the motor breaks, it's likely due to the added weight.
    I'm really shocked at how much weight you gained in a bashing session. I never thought to weigh ours but with the wet season upon us I'm going to check ours on the next run.
    It is clay mud. You know that heavy orange colored Tennessee Clay mud. It is super sticky, it stains anything it gets on the color orange, it is super heavy when wet and it does not easily spray off without at least putting a little elbow grease into washing it off.

    I do a mud run about once a year because of how long it takes to remove this type of mud.

    Quote Originally Posted by Rain Dawg View Post
    Did you go back to running a Max 5?
    Yes.

    Quote Originally Posted by Chewbacca 3 View Post
    I saw these pinion gears and wondered if they may be an easy fix for the X-Maxx.
    I think the motor shaft diameters match, so a gentle grind on the motor shaft to put a flat spot on it should mean the D shape pinion would fit.
    The stock 1600 and 1200XL motors from Traxxas already have the flat spot on the motor shaft, so yes the "D" shaped MOD1 pinions would fit because they are a 5mm bore and no grinding would be necessary.

    Quote Originally Posted by Chewbacca 3 View Post
    I'm not sure it would help and I've not tried it, but it makes a lot of sense in my head.
    I have a brand new 1200XL motor on the way and I am currently waiting on the "D" shaped MOD1 pinion to arrive in the 18 tooth count. Man those pinions are in high demand and hard to find as well. I got one, but I sure had to eat a hefty price to get it.
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  19. #19
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    That's interesting that it is a straight fit, without modification.
    Let us know how you get on. It'll be great news if it fixes the problem people are having.

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  21. #21
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    It was the safe-d5 pinions I had seen.

  22. #22
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by Chewbacca 3 View Post
    That's interesting that it is a straight fit, without modification.
    Let us know how you get on. It'll be great news if it fixes the problem people are having.
    Yes, I will follow-up as a continuation in this thread with more pictures after I get everything. I will even show if the hole that I drilled in my motor shaft has any signs of wear as I am still using that motor currently with the capture solution I presented.

    I believe the safe-D5 pinions are the better solution as opposed to drilling the shaft. I just wanted to show that it could be done as a last resort and work. I had no option but to drill the shaft because when I put a divot on it to prevent the pinion from walking, the set screw still backed out and caused the divot to gull so bad that drilling was the only solution left to continue to keep using the current motor.

    I also conclude that the safe-D5 pinions will reduce set screw fatigue because the hole being "D" shaped allows the pinion to take the grunt of the load and not just the set screw itself being left to bear the grunt of the load as seen with the round hole Traxxas pinions.
    Last edited by Flux Capacitor; 11-14-2020 at 10:48 AM. Reason: Updated.
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  23. #23
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    Quote Originally Posted by Chewbacca 3 View Post
    It was the safe-d5 pinions I had seen.
    It's a quality material from this brand.

  24. #24
    RC Champion grizzly03's Avatar
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    Be weary of the ARRMA safe D5 pinions. I have a 17tooth Mod 1 pinion that doesn't want to go onto a Castle 1717 motor. I've also read on the ARRMA forum others were having trouble also.

    Link to pinion discussion:https://www.arrmaforum.com/threads/a...99t-fit.29194/

  25. #25
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    Update on D5 pinon. It fits on a stock Traxxas 2200kv motor.

    Still won't go on the Castle 1717 motor shaft.

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    Looking forward to seeing how people get on with them now.

  27. #27
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by grizzly03 View Post
    Update on D5 pinon. It fits on a stock Traxxas 2200kv motor.

    Still won't go on the Castle 1717 motor shaft.
    I think I read that the flat spot diameter on most motors tends to gull wider with use and prevent the D5 pinion from going on. I'm sure that if the flat spot extends all the way to the end of the motor shaft and it is a true 5mm, then there should be no logical explanation as to why it wouldn't fit.

    I got a new motor coming and I will mic out the tolerances of the shaft, but I see no reason why it wouldn't fit on a brand new shaft that has the flat spot all the way to the end. Unless Arrmas definition of 5mm is 4.5mm - then there would be a slight problem Houston.

    I mean 5mm is 5mm and if the flat spot does not extend all the way to the end of the motor shaft, then that is the problem most guys overlooked because some of them mentioned the flat spot not extending to the shafts end. If the shaft returns to a round configuration before the end of the shaft, that would stop the D5 pinion from going on in a heartbeat.
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  28. #28
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    Quote Originally Posted by grizzly03 View Post
    Be weary of the ARRMA safe D5 pinions. I have a 17tooth Mod 1 pinion that doesn't want to go onto a Castle 1717 motor. I've also read on the ARRMA forum others were having trouble also.

    Link to pinion discussion:https://www.arrmaforum.com/threads/a...99t-fit.29194/
    Interesting link mate, thanks.

  29. #29
    RC Champion grizzly03's Avatar
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    Here is what I measured with a set of calipers. This is on a new Castle motor and pinion, so there is no wear.



    I'm also not talking about the flat on the shaft, It just won't even start going on the shaft more than a millimeter or two. Looks like possibly where the flat part in the pinion is flat is not perfectly flat.

  30. #30
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    Quote Originally Posted by grizzly03 View Post
    Here is what I measured with a set of calipers. This is on a new Castle motor and pinion, so there is no wear.



    I'm also not talking about the flat on the shaft, It just won't even start going on the shaft more than a millimeter or two. Looks like possibly where the flat part in the pinion is flat is not perfectly flat.
    Thank you for taking the time to share this.

    I'm left wondering if a digital bore gauge would be the way to approach this to know for sure that the Safe D5 pinion is being precision cut/ground down to the last micron.

    At any rate, I recall a thread on here that a member proved the the flat spot on his motor shaft was graduated at a slope instead of being cut at a perfect parallel to the center axis of the motor shaft.

    Also, from my experience of drilling holes in pinions over the years, I wonder if you could just take a small flat steel file and buff out the Safe D5 pinions flat spot because these pinions are not as hard of a material as they claim to be.

    Then again, to truly know if the motor shaft flat spot is perfectly precision ground parallel to its center axis all the way across, takes some skilled measuring with highly advanced tools and machinery.

    Somebody better call MIP because those folks know how to precision cut and grind!
    Last edited by Flux Capacitor; 11-15-2020 at 01:04 PM. Reason: Updated.
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  31. #31
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    If I can find my small set of files I will try running a quick scrape along the flat part. I could also possibly heat the pinion up with a heat gun and it could slide on. But either way the D shape pinions could fix the grub screw issues. The screw would only need to keep the pinion from moving up or down the motor shaft and wouldn't need to hold it from twisting. I think it would be worth the small hassle to fit one on, for the added security it should provide.


    FWIW: Just measured the Traxxas brand 2200kv motor from my Erevo 2.0.
    I measured 4.93" diameter and 4.40" at the "D" part.

    Now i'm curious at what the "D" part on an ARRMA motor would measure at.
    Looks like it's just a minor difference in specs between manufacturers.
    Last edited by grizzly03; 11-15-2020 at 01:21 PM. Reason: measured Traxxas motor

  32. #32
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    Quote Originally Posted by grizzly03 View Post
    If I can find my small set of files I will try running a quick scrape along the flat part. I could also possibly heat the pinion up with a heat gun and it could slide on. But either way the D shape pinions could fix the grub screw issues. The screw would only need to keep the pinion from moving up or down the motor shaft and wouldn't need to hold it from twisting. I think it would be worth the small hassle to fit one on, for the added security it should provide.


    FWIW: Just measured the Traxxas brand 2200kv motor from my Erevo 2.0.
    I measured 4.93" diameter and 4.40" at the "D" part.

    Now i'm curious at what the "D" part on an ARRMA motor would measure at.
    Looks like it's just a minor difference in specs between manufacturers.
    I can't stress enough that is exactly why I am trying the "D" shaped pinions because the pinion takes the grunt of the torque and not the set screw itself being left with the burden of resisting all the torque twist.

    I'll admit that I'm taking another gamble as far as assuming the Safe D5 pinions will fit on the 1200XL motor. I will know soon and I'm hoping that if anything, I would have to shim instead of grind. It is always easier to shim than to grind because you can't put back the ground off material but you can always adjust your shim width.

    But, on the other hand as you adequately pointed out, it is a slight variation between manufacturer specs and the tolerances between them are very close and can almost always be worked around to find something that works.

    It just takes patience and realizing that grabbing an electric Dremel is not always the best choice. Many, many times I have hand filed pieces to fit perfectly because if I would have used the Dremel, I would have ended up with many paper weight projects.
    Last edited by Flux Capacitor; 11-15-2020 at 01:57 PM.
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  33. #33
    RC Qualifier Flux Capacitor's Avatar
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    It's Official!

    The ARRMA Safe D-5 Pinion will fit the stock 1200XL Velineon motor with a slight extension of the flat spot on the motor shaft.

    But first I promised to show how my capture idea was holding up as far as the wear on the shaft hole:



    As you can see, the pin won't even fall out of the shaft hole when the pin was almost vertical. That means the tolerance diameter of the hole did not widen even after ten hard runs on 8S.

    Now when I first ordered the ARRMA pinion, I was afraid of a couple of things. Firstly, I thought the pitch was going to be wrong. Secondly, I thought the width of the pinion would be wrong as well.

    Well, look at this:





    They are both just under 15mm ---- so about 14.5mm is what they come in at. I know digital calipers would be more appropriate to show this; but trust me, the measurements are so close it won't matter for fitment reasons.

    Here they are side by side for clarity on the width aspect as shown by their height from this angle:



    Notice how the ARRMA pinion on the right isn't bored out like the stock pinion on the left?

    Well that is why the motor shaft flat spot has to be extended on the stock Traxxas motors as I'll show with more pictures. Since the ARRMA pinion isn't bored out, the flat spot on the motor shaft doesn't allow the pinion to slide far enough on to come flush with the end of the motor shaft even though both pinions are the same width.

    You also have to do this because the pinions reverse fit as compared to how pinions are normally put on the shaft because the set screw is on the side of the end of the motor shaft instead of being towards the motor side like most pinions.

    So I hand filed the flat spot to extend it further towards the motor:



    I like hand filing metal because I can actually feel with my fingers if the file is at the right angle and it is more controllable than a Dremel. After about seven minutes of careful filing, the ARRMA pinion fit just right:



    I actually left enough on the motor shaft that it fits a little snug.

    And here are the comparison pictures that show that both pinions are the same distance away from the motor mount when flush with the end of the motor shaft:





    I can't wait until I get my new stock 1200XL motor so I can put this ARRMA pinion on it. At least I was able to get some filing practice on this old motor shaft first, so I know I'll be able to get the new motors shaft right when the time comes.
    Sent from my autonomous device.

  34. #34
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    Great job. Hope it performs well once you get it up and running.

  35. #35
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    Quote Originally Posted by Flux Capacitor View Post
    The ARRMA Safe D-5 Pinion will fit the stock 1200XL Velineon motor with a slight extension of the flat spot on the motor shaft.

    But first I promised to show how my capture idea was holding up as far as the wear on the shaft hole:



    As you can see, the pin won't even fall out of the shaft hole when the pin was almost vertical. That means the tolerance diameter of the hole did not widen even after ten hard runs on 8S.

    Now when I first ordered the ARRMA pinion, I was afraid of a couple of things. Firstly, I thought the pitch was going to be wrong. Secondly, I thought the width of the pinion would be wrong as well.

    Well, look at this:





    They are both just under 15mm ---- so about 14.5mm is what they come in at. I know digital calipers would be more appropriate to show this; but trust me, the measurements are so close it won't matter for fitment reasons.

    Here they are side by side for clarity on the width aspect as shown by their height from this angle:



    Notice how the ARRMA pinion on the right isn't bored out like the stock pinion on the left?

    Well that is why the motor shaft flat spot has to be extended on the stock Traxxas motors as I'll show with more pictures. Since the ARRMA pinion isn't bored out, the flat spot on the motor shaft doesn't allow the pinion to slide far enough on to come flush with the end of the motor shaft even though both pinions are the same width.

    You also have to do this because the pinions reverse fit as compared to how pinions are normally put on the shaft because the set screw is on the side of the end of the motor shaft instead of being towards the motor side like most pinions.

    So I hand filed the flat spot to extend it further towards the motor:



    I like hand filing metal because I can actually feel with my fingers if the file is at the right angle and it is more controllable than a Dremel. After about seven minutes of careful filing, the ARRMA pinion fit just right:



    I actually left enough on the motor shaft that it fits a little snug.

    And here are the comparison pictures that show that both pinions are the same distance away from the motor mount when flush with the end of the motor shaft:





    I can't wait until I get my new stock 1200XL motor so I can put this ARRMA pinion on it. At least I was able to get some filing practice on this old motor shaft first, so I know I'll be able to get the new motors shaft right when the time comes.
    This is an excellent work, my friend.

  36. #36
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    Excellent R&D on the pinions and will be serving as a major shortcut for those with issues and those that want peace of mind.
    Is the new 1200 XL motor for backup incase the shaft on this one goes? or are you having issues with it?
    As always thanks for the detailed work, you make it look easy.

  37. #37
    RC Qualifier Flux Capacitor's Avatar
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    Quote Originally Posted by Chewbacca 3 View Post
    Great job. Hope it performs well once you get it up and running.
    Thank you!

    I really hope this new style of pinion will prevent the set screw from backing out so I don't have to drill a hole in another motor shaft.

    Quote Originally Posted by Juanmacine View Post
    This is an excellent work, my friend.
    Thank you as always Juanmacine!

    Quote Originally Posted by Rain Dawg View Post
    Excellent R&D on the pinions and will be serving as a major shortcut for those with issues and those that want peace of mind.
    Well technically, I really didn't do any R&D on anything, I just took what was available on the market and made two different brands shake hands and play nice.

    Quote Originally Posted by Rain Dawg View Post
    Is the new 1200 XL motor for backup incase the shaft on this one goes? or are you having issues with it?
    I have no issues with the current motor and it is just a matter of making a decision when I receive the new motor if I want to start using it right away or not. To use the D5 pinion though, I would have to use the new motor because my current motor shaft has the hole in it and was made to exclusively support the pin capture idea unless I cut one of the pin grub screws down that look like this and was mentioned earlier in the thread:



    Quote Originally Posted by Rain Dawg View Post
    As always thanks for the detailed work, you make it look easy.
    You're Welcome and Thanks for the feedback!
    Sent from my autonomous device.

  38. #38
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    New Testing with a new motor and new pinion.

    So I finally got that new motor in today. USPS lost the first one; so a big shout out to Honesthobby for sending the new motor by FedEx!



    First of all, I have to explain that this seems to be a hit or miss with the fitment between the ARRMA safe D5 pinion and Traxxas motor shaft. As you can see from the picture above, I was only able to get this 18T pinion about maybe 1mm on the shaft before wedge lock stopped it from going all the way on.

    I measured and measured and measured the heck out of everything and came to the realization that either the pinion or motor shaft are going to have slight inconsistencies that prevent a perfect fit. In this case, the ARRMA bore on this 18T pinion has a skewed bore angle I was able to determine is off by less than a thousandth of a degree as best I could measure with digital elementary tools.

    Without a fitment press to hold the pinion for laser measuring I can't get an accurate read on the exact degree entry and exit bore of the hole; but the Traxxas motor shaft is telling me it is off ever so slightly and I can fix it. It is just a matter of fine filing the shaft to accept the skewed bore hole on the pinion; actually, the fitment is so darn close that I'm just going to heat the pinion up to get it on.

    My motor on the truck now is using the 14T ARRMA safe D5 pinion and it needed a shim to make the pinion fit better:



    This is the shim that I cut a piece from to wedge in the pinion to shaft hole on the flat spot because my old motor has that shaft that is pretty beat up:



    The trick is to get the pinion and shaft to have zero rotational slop between them. If you put that ARRMA pinion on and there is the slightest bit of rocking play between the shaft and the pinion, you will end up with the set screw backing out problem all over again.

    Once I fine tuned that motor shaft and pinion fitment with the shim, the one on the truck now hasn't moved in over a week and neither has the set screw. My new motor being late gave me the opportunity to test with the old motor and pinion first so that I can get this right on the new setup.

    The more I think about this though; with the new motor shaft and new pinion, I'm not going to file the motor shaft other than on the round part to extend the flat spot and just use heat to get the pinion on all the way. There is no need to file my existing flat spot on the shaft to make the pinion fit, it just needs a slight bit of heat to get it to go on.
    Last edited by Flux Capacitor; 11-30-2020 at 05:50 PM. Reason: Updated.
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  39. #39
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    What did you have to shim exactly?
    Sorry, I'm a little confused. Lol

  40. #40
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    Quote Originally Posted by Flux Capacitor View Post
    The more I think about this though; with the new motor shaft and new pinion, I'm not going to file the motor shaft other than on the round part to extend the flat spot and just use heat to get the pinion on all the way. There is no need to file my existing flat spot on the shaft to make the pinion fit, it just needs a slight bit of heat to get it to go on.
    I ordered a new 21T Safe D Arrma pinion to install on my Castle 1717 motor. Same issue with not fitting. I've been trying to find my small hobby file set. But I'm thinking they must have grown legs and walked off, LOL! I was going to try filing slightly on the flat part in the pinion.

    Let me know how the heating up to expand trick works.

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