1515H/2.5D Bearing replacement w/pics

[RobertAbles]

O.k. kids here is my 1515H torn down. After 3 months, the top bearing started to squeal. The motor comes apart very easy as the fan shroud and the end cap are held on with silicone. No epoxy requiring heat. I used two wood blocks under the edge of the fan shroud and tapped the motor right out. Then, removed the 4 screws in the end cap and used a small flat screw driver to pry off the end cap. Very little silicone was used so it was easy to get off. Tapped out both bearings with sockets and this all took about 3 minutes. Steve Neu recommended just a small amount of high grade silicone to re-assemble. The fan end bearing is a 5x16x5 and the pinion end bearing is a 5x11x4, No flanges! Here is the link of the two bearing I ordered as I think it is worth going ceramic hybrid on this motor. I will update once the bearings come in and I get a test flight in.
Pinion end bearing: http://www.vxb.com/Merchant2/merchan...Category_Code=

Fan end bearing: http://www.bocabearings.com/main1.as...=SMR625C-ZZ_#3

[aucmax]

I ordered this bearing a few weeks ago for my 1515/2.5 D/H for "just in case" later issues.

http://www.bocabearings.com/main1.as...99&n=SMF695-ZZ

It is flanged (5x13x4) and does not match the same specs as the bearing link you posted (5x11x4). Is this bearing the wrong size? When you disassembled your motor, were the bearings flanged or does this really matter? I am a bit confused at this point. Wren can you chime in on this one?

[Mercuriell]

Unfortunately there seems to be at least 3 different varieties of 1515/2.5d all using different bearing sets - mine is the oldest with 2 11x5x4 bearings - Alan had a flanged 13mm variety and Rob's had a socking big flanged 16x5x5 ! So I guess Brett id depends which Mk yours was - on the good side at least Neu are addressing the bearing issues in the highly stressed 1515 series !

[aucmax]

John! Your not helping here! How do I know what flavor I have? I guess it is just pick and choose, they all will work so who cares? Sh*t man! Tune me in on this mate.

[wren1702]

Mine was the "F" version, not the "H" Version. Enough to drive one mad isn't it!

At least they are so easy to take apart.

[aucmax]

Yeah.. That's me on the left.

[Mercuriell]

Originally Posted by aucmax

Yeah.. That's me on the left.

Looks like my vasectomy clinic

[StatiC]

Thanks for that info. I don't think the 1515 H series breakdown has been explained before that I could find. I was wondering how the fan shroud was supposed to come off. If I need the info in the future it is nice to see it posted.

[RobertAbles]

Fan does not come off the shaft. This 1515 H was bought in Dec. 07!

It appears that the F has flanged and the H does not. It is so easy to take apart, you could do it just to see without pulling the bearings. I guess the older F and the newer F have different bearings.

Hope this helps!

[Bill Sanford]

Great info!

I just received my new Neu 1515H-2Y and I am considering tearing it down and putting in a ceramic hybrid bearing on the pinion side even before I install it.

It sounds like the only way to be sure of the bearing size is to tear it down, so I guess I'll do that and place an order...

If it's a 13x5x4 flanged, the only option I've found is at Boca Bearings and it's $35 !
http://www.bocabearings.com/main1.as...=SMF695C-ZZ_#7

If it's a 16x5x5 flanged, then I haven't been able to locate a ceramic hybrid anywhere!

Anyone have any leads for me??

Bill

[StatiC]

Originally Posted by robmoney

Fan does not come off the shaft. This 1515 H was bought in Dec. 07!

I meant to say the fan shroud . I wouldn't need to remove the fan itself.

[RobertAbles]

vxb.com and Boca are your choices from what I have found.

Call Boca, they are very helpful and may have something you can't find on the site...

The fan end bearing is o.k. in my motor so the ceramic in the pinion end SHOULD help longevity anyway.

Bill Sanford, I bet your motor is NOT flanged being it's a new 1515H! So you should be able to order the same bearings I did... Take it apart just to be safe though...

[Bill Sanford]

Originally Posted by robmoney

Bill Sanford, I bet your motor is NOT flanged being it's a new 1515H! So you should be able to order the same bearings I did... Take it apart just to be safe though...

Weird! Both bearings are the same on my 1515H-2Y -> 5x13x4 and BOTH are flanged!

How many different varieties of the 1515 did Steve make??

This is a brand new motor (never ran) and I was surprised to feel that both bearings felt just slightly rough! They don't feel silky smooth like I think they should. I've actually changed bearings in my helis that felt like these!

The only flanged 5x13x4 ceramic hybrid bearing on the Boca site costs costs $35 each! It is ABEC #7 rated, which is MUCH higher than necessary, which is likely why it is so expensive. From what I understand and read on the Boca web site, the ABEC rating just rates the precision that the bearing is made as far as dimensional accuracy. I don't think it's an indication of hardness of material or how long the bearing will last...

I spent a little time looking with Google, but didn't find what I was looking for...

Any suggestions guys? Do you know of anywhere else I might find 5x13x4 ceramic hybrid bearings for less? I don't need ABEC #7 rated...

Bill

[RobertAbles]

ABEC rating has to do with tolerance, so the higher rating does have less slop, so this should give a longer life in a high vibration enviroment I would think.

[4cyclic]

Excellent info Rob, I had to return my 1515DHF twice to Neu for bearing replacement. Although the turnaround time was quite impressive at 2 weeks, it is even better if I could just pull the motor and replace with hybrid bearings myself.
I just cringed at the thought of using a torch and a wood chisel on the 1500 series as previously posted. Silicone seems a much better solution than GBWeld.
Is a Hight temp silicone used or the regular clear GE type ??

[RobertAbles]

4cyclic

I have the same GE bathroom 100% clear silicone in my cabinet and it says that it should not be used over 400 degrees F, so it is more than enough. I haven't temped this motor over 130 yet...

I think the trick will be to get the old stuff cleaned off and use a little alcohol to clean up before re-assembly.

It took no heat, and really the screws hold it together not the silicone. It is probably for vibration issues more that adhering the cap on...

Neu specs out only ABEC3 steel bearings for these motors, so when they repair it, it gets the same cheap bearings...

I will see how the ceramic hybrids hold up..

[Bill Sanford]

My previous post about an ABEC7 rated bearing being too good is probably a dumb statement on my part!

When I considered what I have invested in the motor, and the entire heli... a $35 bearing isn't really a big deal, especially if it fixes a known point of failure. It's cheap insurance if it prevents destroying the motor, or risking the entire heli if it were to fail in flight!

Based on this, my question is: Do I need ceramic hybrids on both ends of the motor, or would a good quality stainless bearing from Boca on the non-output side be adequate?

Has anyone had a bearing failure or even serious wear on the non-output side of a 1515 or any other motor?

[RobertAbles]

I think a steel ABEC3 or better on the fan end is fine, I found my 2 bearings for 15 and 18 bux each so I went with ceramic on both..

[Bill Sanford]

OK, next question is lubrication...

Have you guys seen this thing: http://www.heliproz.com/prodinfo.asp?number=169165

It VERY cool and it's now on my MUST HAVE list!

A friend bought one and I borrowed it from him. It is a bearing greaser that forces grease around the dust shields of bearings and fills it with grease. It works absolutely great!

I used it to grease the main shaft bearings, the grip bearings and the tail shaft bearings.

None of the bearings were bad, but most had been flown quite a bit. You should have seen the black icky grease that was forced out of a few of the bearings! They are now full of clean fresh synthetic tri-flow grease and should last a LONG time!

Should I use this to lubricate the new bearings on the motor? My concern is that the motor runs at such a high RPM, will the bearing being FULL of grease cause them to drag and potentially wear the shaft due to slippage between the inner race and the shaft?

I suppose I could use green loctite to bond the shaft to the inner race...

Any comments guys? What do you think?

Bill

[RobertAbles]

The oil/grease used by the bearing manf. is important in material type, ball type, speed, heat. etc. ratings on each bearing. I don't grease my own as you need to get the old grease out first.. I run the bearings until they need replacing.

Maybe if you get dry bearings, then you can grease them yourself, IF you know what type lube is best for the application and materials of the bearing. I don't know enough about it, but a local bearing company did tell me that it's not a good idea to mix lubes inside the bearings.

We need a bearing expert on here to educate us a little more on bearing lube dos and don'ts!!