Medusa Endbell Mod
 

Since Medusa is not honoring any more warranties, I figure I had to fix my motor myself. I was running my XT8 truggy in reverse when I hit something quite hard. This caused the rotor to pop the rear endcap off. The endcap is not crimped or anything, just glued. So, until Mike has his heatsink/clamps available, I figured I'd do what I can to fix it.

First, I found some screws that would be small enough to work. As you can see, length is very important so they don't hit the coils, so I dremeled one down.

http://scriptasylum.com/forumpics/medusa_mod_1.jpg


Then, I measured about 2.5mm from the end of the motor can (excluding the end cap lid) and drilled two 1/16" holes on each side of the motor just far enough to go through the outer motor can, and then mark the endcap, but not all the way through (to avoid hitting the coils).

http://scriptasylum.com/forumpics/medusa_mod_4.jpg


I then removed the endcap and finished the holes in the endcap.

http://scriptasylum.com/forumpics/medusa_mod_5.jpg


Then, I pulled the endcap as far as possible before it would pop off and gooped a bunch of red locktite around the edge. To make sure the red lock-tite would work, I called Locktite and spoke to a tech. After explaining my situation and application, they suggested the red for its heat properties, and recommended the gel to avoid it dripping where it shouldn't.

http://scriptasylum.com/forumpics/medusa_mod_6.jpg


After snapping the endcap in place, wiping off the excess locktite, and screwing the trimmed screws in place.

http://scriptasylum.com/forumpics/medusa_mod_7.jpg


I probably should have used three screws, but couldn't find one small enough anywhere. I just happened to have the two I used in my screws bin.

Anyway, after letting this cure overnight and most of today, I made an experimental solid tap on the pinion side of the rotor and it seems to be solid. A little driving around worked fine too. Time will tell if this will work long-term (or until CC releases their 1800kv motor).

Brilliant Mod Brian! :yes:

I've been thinking of attempting this myself. Maybe using more screws.

The endbell is a really snug fit. I wonder if using 4 - 6 screws and just loctiting the screws would be enough? Maybe with the Blue or possibly the green?

I would love to make my Medusa's easily rebuildable.

What version are you working on there?

Wow, nice. I don't think I'm accurate enough to drill such small holes so precisely at the end of the motor though.
Do you think using some CA glue would hold the endbell in?

Oh, and that looks like a V2.

Thanks guys! :smile:

CA glue probably would not stand up to the shock and heat on a motor (especially heat). Not to mention CA works by chemically bonding with plastic/rubber, which probably won't work as well with metal, if at all. I was thinking about JBWeld too, but noticed that it tends to get softer with heat. I don't plan to overheat my motor, but better safe than sorry. From what I understand, Locktite works by turning into a plasticy substance and expands, while bonding somewhat to the metal, so I figured this would work better. And the screws are just to make sure. I may add a couple more screws if I can find some that are the right size.

It doesn't take much accuracy to drill the holes; just go slow and apply "back resistance" so you don't break through and hit the coils. In my case, I had nothing to lose since the motor was pretty much shot as it was.

Man, you really think things through before you do them. I wish I could do that. :lol:

Nice Job. :great:

Great Job Brian...Did medusa really stop honouring warranties?... just for you for or for everyone else?... Did you make that solder joint or was it like that...

What motor is that? The 36-70-2000kv?

Reason why I'm asking, I like to compare winds and those are some really good pictures. :yes:

I figured it was just a matter of time before someone did something like this. It's pretty much a Neu now! I would take it one step farther and get a tap and thread the end cap so the screws go into it, just like a neu, and only use a dab of loktite on the screws instead of the whole end so I could get it apart in the future.

According to their site, they are only doing repairs for what they already have in house, and any en route. No more new repairs. The solder joint was like that. Funny you should mention that because I was looking at it and I see three sets of coil wires that are joined, which leads me to believe it's a Y wind (the solder joint would be the intersection of the Y).

36-80-2000.

Maybe I should have taken a better picture of the endcap, but there's really not much thickness to tap. It's maybe 1.5mm thick, if that.

Edit: I found a picture that shows the thickness of the endcap so you can see it's not that thick at all:

http://scriptasylum.com/forumpics/medusa_mod_3.jpg

Mine came off and they are charging me 74 dollars to just give me a new motor. I probably should have tried to fix my own also.

Wow, that's a bit much. More than half the price of a new motor! Ideally, Mike's heatsink/clamp would be a better solution, but I'm not sure now if he's gonna make them. I hope he does, because there are other 36mm smooth motors out there where they can be used.

I had to do the same thing with my Faegiao motor because the rear kept popping off and a bad wreck into a storm drain took the front endbell out. I used 4-40 X 3/16 button head screws. And also used the Green Locktite sleeve retaining compound. (it's what they use when they have to replace a sleeve in a lot of LS and Hemi and other engines). I had some laying around and Snelliemin needed to bond a rotor back onto the shaft of one of his motors.

jb weld would hold it for life. I used it to secure the front endbell of my huge kb45, and its spaced 4mm from the motor mount with one of mikes spacers, yet it holds the weight of that huge motor.

For an 80mm you could have just used mike's XL heatsink...

problem is they are out of stock and have been for ages.

Ahh maybe nows a good time to unload my spares :)

Exactly! Don't you think that was my first choice?

Brian - sometimes you get "creative" just because - FYI bit small but the S is in stock...

I'll check tonight but think I have a spare really rare, highly sought after XL at home that I could sell.

Brian, I used CA glue to glue the endbell back on a 540C 7XL motor because the the threads were stripped after the cover got knocked off after a crash.

Anyways, I tried to turn the endbell off, it doesn't budge. :smile:

Well, for threaded endcaps, that might be fine, but the Medusas are just press fitted.

I had used little screws for my endbell on my 36-60-2000 in my E-revo. Unfortunately eventually one did break out the motor can. I probably could have had the hole a little further away from the edge. But it was caused from a 20 foot, double backflip rear dive . Sane people should be alright. I just electrical taped it after that, the 1 screw and tape held out.

Just an update: I found an extra tiny screw so I added it to bring the total to 3 screws. And when I took it apart, I found the red locktite didn't hold too well (so much for locktite tech support). So, I used JBweld after all.

And for the ultimate test, I bashed the heck out of the XT8 and everything held up. Play was stopped by an obliterated rear diff case (the part that attaches to the chassis, shocktower, etc).

I didn't think that red would hold that's not its purpose. The green sleeve retaining compound will hold. It's still holding up on my motor. They also recommend using the primer before using most of their products. I haven't used it before except when I worked for Western Atlas where it was part of the procedure.

Using Loctite is just like anything else it has to be used properly if the surfaces are not completely clean and free anything but the substrate you are attaching it won't bond. If there is any oil at all it won’t set. Anodizing needs to be removed and both surfaces roughed up for it to work, same with JB weld although I have yet to find anything that it is good for. At least it never works where I need it to.


Jeff

When I applied the JBWeld, I did take off all the anodizing and roughed it up with a dremel sanding wheel. So, that coupled with the screws should hold.

When you opened it up, did you notice that it didnt have any shimms?

It will probably hold on the end bell, but if it let go on the front it might hold for a little while. When I got my Faegiao the end bell was already popping off. My biggest problem was that the front one came off in a nasty crash. After that was when I decided to use screws to hold it in place. After checking it while bashing I noticed the motor was "loose" so I took it back apart and used a dremel with the wire wheel to clean it then reattached everything and added the green sleeve retaining compound. (there are several Green compounds most are low strength threadlockers). Let us know how it stands up.

Jeff

I use red loctite on my pinions a little heat from a soldering iron on the shaft and they pop right off - no good for the end bell. Can someone tell us aussies
what this JB Weld glue is

Well you aussies have Google?:lol:
Its one of those two component glues.

I will stick with Loctite 603, i have stuff that is meant to secure bearings, that should be realy nasty stuff and should hold...

JB weld is a 2 part epoxy and is one of the most widely known here in the US. There are tons of different 2 part epoxies around here. I think there are a lot better ones out there but some are just worthless. I have had good luck with some of the stick epoxies that you kneed together but it wouldn't be right for this application.

603 is a good, there are really a ton of different compounds that will fit this application there are ones for bearings (like the 603) and ones for loose or worn out bearings (really) I think the tolerence on that was .025" (.5mm). You can find this stuff at industrial bearing suppliers, but look up what you want first, because most might not have it in stock and they will try to sell you "something close".

Jeff

Wow, I haven't been on here for ages! Helps to have a PC that works too. :lol:

Here's my Medusa.
Will I have trouble with the endbell separating from the can?
http://i55.photobucket.com/albums/g1...CMHeatsink.jpg