Arrma Safe D pinions don’t fit

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jondilly1974

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Why did Arrma make these Safe D pinion bores so small? They won’t fit any other motors I’ve tried. I have a 25T from a K8S and it will only fit the 1250kv motor shaft. Won’t fit a 1717, TP 4050, etc. ??‍♂️?
 
Why did Arrma make these Safe D pinion bores so small? They won’t fit any other motors I’ve tried. I have a 25T from a K8S and it will only fit the 1250kv motor shaft. Won’t fit a 1717, TP 4050, etc. ??‍♂️?
Arrma be like:
A84D2FF6-3C73-406F-887A-A12F64D024D3.png


Use our spektrum motors ;)
 
Why did Arrma make these Safe D pinion bores so small? They won’t fit any other motors I’ve tried. I have a 25T from a K8S and it will only fit the 1250kv motor shaft. Won’t fit a 1717, TP 4050, etc. ??‍♂️?

That is good to know. I kept the 25T but now might as well trash it :ROFLMAO:
 
That is good to know. I kept the 25T but now might as well trash it :ROFLMAO:
Thinking of taking a dremel to it but afraid to make it out of true. I don’t have a file small enough to do it by hand.
 
heard someone say to grind nub off end of shaft.i wouldn't feel comfortable thying that
Wouldn't getting the right pinion be easier???‍♂️ ya that's some BS thou.wheres the little c clip keeper supposed to go???mine in trash
 
heard someone say to grind nub off end of shaft.i wouldn't feel comfortable thying that
Wouldn't getting the right pinion be easier???‍♂️ ya that's some BS thou.wheres the little c clip keeper supposed to go???mine in trash
I'm trying the opposite. Trying the Arrma pinion on a TP motor.
Is it close? Or not even? Could take some red scotch bright and stuff it through the middle and run it back and forth.
I thought about using a BFH
 
Yeah, it's something that just doesn't work - blame the motor or the pinion. The motors I've seen have a milled out flat for the grub screw that doesn't go all the way down to the tip of the shaft and so the "D" shape of the pinion hole doesn't slide over it.

Just another set of pinions to stock, I guess. I like the concept of the SafeD system
 
Yeah, it's something that just doesn't work - blame the motor or the pinion. The motors I've seen have a milled out flat for the grub screw that doesn't go all the way down to the tip of the shaft and so the "D" shape of the pinion hole doesn't slide over it.

Just another set of pinions to stock, I guess. I like the concept of the SafeD system
The hole in the pinion is smaller than normal pinions, even if you don’t factor in the flat spot. It would seem they wanted the tightest fit possible or use a slightly smaller shaft on the 1250kv? I have the 1250kv motor and other pinions fit fine.
 
The hole in the pinion is smaller than normal pinions, even if you don’t factor in the flat spot. It would seem they wanted the tightest fit possible or use a slightly smaller shaft on the 1250kv? I have the 1250kv motor and other pinions fit fine.

That was my exact thought also, what if the shaft is 0.1 or 0.15 smaller? That would leave some wiggle room with saga pinions or other brands... scary if so!
 
Just measure mine and it's dead on 5mm. I do not have a motor to try though.
Might just be the 'lip' on your motor i.e. the initial bridge. This 'lip' might dis-form and get a little larger with standard pinions. This is a tolerance issue at best.
Fine sandpaper on the shaft should do it.

Update: Just tried it on an old BLX and doesn't fit either. Both measure exact 5mm on my caliper. ?‍♂️

Update update..doh..that Safe-D 'notch out' hits that lip I mentioned. It's not a 5mm hole on the pinion. Kinda obvious after the fact.
You would have to dremel off that edge on the offending motor shaft to make it work.
 
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Just measure mine and it's dead on 5mm. I do not have a motor to try though.
Might just be the 'lip' on your motor i.e. the initial bridge. This 'lip' might dis-form and get a little larger with standard pinions. This is a tolerance issue at best.
Fine sandpaper on the shaft should do it.

Update: Just tried it on an old BLX and doesn't fit either. Both measure exact 5mm on my caliper. ?‍♂️

Update update..doh..that Safe-D 'notch out' hits that lip I mentioned. It's not a 5mm hole on the pinion. Kinda obvious after the fact.
You would have to dremel off that edge on the offending motor shaft to make it work.
My TP 4050CM doesn’t have any lip?
 
That 'Safe-D' shape is 4.5mm on the flat side, maybe the shaft has a different flat spot diameter. That is the only thing holding it back.
 
I've got a 22T stuck on Spektrum 1250KV motor. Can't get the Safe-D pin off either. I'm removing everything Spektrum from my rig so I guess I'm gonna lose the pinion gear as well. I've tried everything from a fine tooth tweezer, to my nsils (OUCH!), to pliers...Pissing me off really. Seems like Spektrum does little things like this to make their product exclusive to them and leaving you stuck to keep buying their stuff. Another example would be the 23T servo horn for their servos when most all other brands use 25T. If their stuff was above average quality I wouldn't complain but I'm finding out that it's not hence my removal of EVERYTHING Spektrum. Almost made me want to quit the hobby!!!
 
Don't forget to hate on Hobbywing while you are at it. Spektrum is just rebranded Hobbywing. Sell your stuff in the classifieds, I might take it.
I had planned on it once I get everything replaced and I'm back up and running. Been really frustrated. Probably gonna unload the 6100AT receiver and the DX5 Pro transmitter first. Can't sell the motor with a 22T permanently stuck on it. Then the 160A ESC at a deep discount cause I had to cut the mounting legs off to fit my Talion. It will come with the ESC programmer though and the USB cable connector. I need s break...I kinda went all in on Spektrum and was HIGHLY disappointed. I didn't even mention the $145 servo I bought that was dead on arrival (had to go and get a Reefs)!!
 
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