Motor Question

[tomdooly]

Tower currently lists the following OEM parts for the OS EF1 motors:

OS stock# Description
74004010 Main shaft for OS 3820-1200
74004014 Main shaft for OS 3820-1200W
74004011 Stator Assembly for OS 3820-1200 (includes bearings)
74004000 Prop Driver for OS Series-38 motors

Also, search EBAY for "OSA 3820-1200" and "OS series 38" for other sources
of OS OEM parts.

[kane]

Tom,

Thanks for the info. I forgot about the OS, being that it was discontinued.

Does anyone have any info on bearing cost from a NON-OEM source? And source? (for any motor).

DK

[dscherrer]

Hi Dan,
about all I can find is for the Eflite motors.

Here are the links.

http://www.bocabearings.com/bearing-inv ... -bl-1250kv
http://www.bocabearings.com/bearing-inv ... -bl-1250kv
http://www.rcbearings.com/products/efli ... rings.html

Guess if you want to pay the price for the boca bearings, you can.

There might be some options for the Rimfire on Boca Bearings as well, however, there is nothing specific. the only way to tell is to open the motor and measure the bearings...not worth it on the others for now.

Doug

[fizzwater2]

the 5x11x4mm bearing in standard steel, with metal shields, is 1.97 at RC-bearings.

The 5x14x5 bearing in standard steel (not stainless) with metal shields, is 2.07 at RC-bearings.

those are the sizes listed in the "kit components" tab for the e-flite motor at the other bearing place.

[RSmith]

Dan,
A few years ago I replaced the bearings in an EFlight motor with non-OEM. I just went to my local bearing supply shop in Calgary with the measurements. They were nothing fancy. Basic steel bearing with metal shields. I think the pair was about $10.00 It probably cost me more to drive there.

I replaced the bearings because I had a cart wheel on landing that smacked the spinner. The front bearing sounded rough after that.


Randy

[uavflyer2k]

I'm gritting my teeth trying to NOT get in on this one

But----,since there are backroom discussions about this, I'll chip in!

To my knowledge there is nothing you can do by changing the shaft or bearings (unless you have bad ones) that will give your "Approved" OEM motor some sort of an advantage over a box stock one. You can spend a lot of money on the "super" ceramic bearings and they may seem smoother but the motor will not run faster.

However you definitely can save a few bucks if you have a bent shaft and replace it with anyone's 5mm shaft that fits, or anyone's bearings that are the same size as the OEM ones. In the case of bearings, it would probably be impossible to tell if they are "NOT" OEM, as the manufacturers source them from the same places as Boca, someone on EBAY or RCBearing does.

I personally feel that those parts should be changeable as simple "normal maintenance" items, since they are the parts most susceptible to wear and tear from use.

Basically I see no downside to allowing them to be replaced at will. It will allow the racer to replace bad/bent/worn-out parts and will not cause the motor to begin performing any better the it originally did.

Ted

[edh-13]

Randy is 100% correct. You CANNOT replace any bearings (THIS MEANS OEM OR NON OEM). You CANNOT replace the motor shaft (THIS MEANS WITH MATERIAL YOU PURCHASED AT MCMASTER CARR OR OEM). You CANNOT take your motor apart to turn the shaft around.

Why? Because that is the rule. It doesn't matter that nobody can tell, It doesn't matter that you did this two years ago, it is still not allowed.

The NMPRA is having a behind the scenes discussion to see if this stance should change. As of right now no decision has been made. When a decision is made I will update everyone.

DK

I couldn't disagree more with this statement. I may be a rookie to EF1 but I've been heavily involved with spec class motorsports for 30 years. The way the rule currently reads there is absolutely no reason you can't return a motor to STOCK CONFIGURATION. If the intent of the rule was to keep the motors "as delivered" or "untouched" from the manufacturer, use THAT language.

And if the intent was to keep the engines as delivered with no relief for repair, than I don't know if this class was all I hoped it would be.
Eric Huffman
25D

Eric,

The intention was to not allow the motors to be opened up. Both the written word and the intention of the rule must be adhered to. I have explained both. I am sorry you feel this class won't be what you want, because we tell you not to open up your motors.

BTW, some motors on the approved list do not have any spare parts.

We want this event to be fun and easy. AS stated above we are looking at possibly modifying this rule and I will post something once a decision is made.

DK

Sorry, after reading my post it sounded a little more harsh than I intended. Trying to level the playing field by keeping the 'tuners' from fiddling with things is a noble effort and hard to achieve without unintended consequences. I don't have any answers on how to allow a repaired motor without opening up the barn door for mods unless you create an enforcement process nightmare that nobody wants.

I'm a big fan of EF1 and a little bit of a cheerleader at my local club - Even after laying an egg at Winterfest

The guys who put this class together did (are doing) a great job and I trust that whatever solution you come up with is best to build EF1 participation.
Thanks for all the hard work! I'm having a blast even while getting beat like a Cardinal in Carolina!
Eric Huffman
25D