4wd front one-ways and spools
10-16-2007, 09:32 AM
#1
4wd front one-ways and spools
I was looking around for the advice people had on keeping the xxx4 outdrive shafts from falling out or being pulled out of the one-way bearings. In the meantime, something occurred to me. I was looking at other one-way units that seem to be a solid chunk of aluminum with an offset flange that you bolt the pulley gear to (call that TYPE1). If you compare that to the Losi one-way, Losi's is 2 separate shafts (call that TYPE2).
Just fiddling around with the Losi one-way, it seems that you could practically guarantee that an outdrive would not slip out if the 2 shaft were actually connected to each other (like in a TYPE1). You would have to unscrew one of the outdrive cups from the shaft, then pass the shaft through the one-way bearings, then put the outdrive cup back on.
I don't know if the handling would change in a bad way, good way, or no noticeable way. Any thoughts? It would just seem that if the car were coasting or breaking into a turn, that the front tires might slip more with a TYPE1 than a TYPE2.
Just fiddling around with the Losi one-way, it seems that you could practically guarantee that an outdrive would not slip out if the 2 shaft were actually connected to each other (like in a TYPE1). You would have to unscrew one of the outdrive cups from the shaft, then pass the shaft through the one-way bearings, then put the outdrive cup back on.
I don't know if the handling would change in a bad way, good way, or no noticeable way. Any thoughts? It would just seem that if the car were coasting or breaking into a turn, that the front tires might slip more with a TYPE1 than a TYPE2.
10-16-2007, 09:38 AM
#2
The Losi one-ways are really pricey to fix and they fall apart easily. There's a place overseas (UK?) that makes a nice one-way for them, with full-sized bearings. I think Tech Racing also makes one.
I got fed up with mine and sold the car...LOL...$30 each night...no thanks.
I got fed up with mine and sold the car...LOL...$30 each night...no thanks.
10-16-2007, 10:12 AM
#3
You may be thinking of Lesro. That is the kind of one-way that seems to be a solid shaft all the way from left-to-right. I heard the problems people had with the Losi one-way is when the outdrive cup/half-shaft would slip out of the one-way bearing while under power. I am proposing that a simple shaft that would look like the 2 Losi half-shafts welded together would function similar to a Lesro unit, but it would be a very simple machined part that would "drop right in".
10-16-2007, 10:34 AM
#4
You may be thinking of Lesro. That is the kind of one-way that seems to be a solid shaft all the way from left-to-right. I heard the problems people had with the Losi one-way is when the outdrive cup/half-shaft would slip out of the one-way bearing while under power. I am proposing that a simple shaft that would look like the 2 Losi half-shafts welded together would function similar to a Lesro unit, but it would be a very simple machined part that would "drop right in".
10-16-2007, 10:37 AM
#5
I own a lesro oneway and it does not have a solid shaft like you are describing. Each side has a seperate shaft. If the shaft was welded together like you describe it would not give proper oneway function. Both sides have to be able to spin independently of each other to get the desired oneway action. What makes the Lesro stronger is that it has bigger oneway bearings and the shaft engages more into the bearings unlike the Losi unit.
...what he said. 
10-16-2007, 10:38 AM
#6
I've never heard of "Lesro". The one I'm referring to was a standard one-way that fits XX, XXX-S and XXX-4 models...I think it was "Apex"?
Thye use a standard (5mm?) one-way bearings, instead of the tiny and fragile Losi bearings. The bearings in my Lazer have lasted 2 years...the Losi bearings, maybe 2 heats.
What you're describing sounds like an X-Ray Multi-diff...you can make it into a "one-way spool". Not many people use that configuration in 4wd off-road (never heard of one myself). It's generally either ball diff, spool (solid axle), one-way or (on shaft cars) a center(shaft) one-way or a one-way center pulley in some belt cars, with either a spool or a ball diff.
I love front one-ways myself...great turn in and corner speed...much smoother.
Thye use a standard (5mm?) one-way bearings, instead of the tiny and fragile Losi bearings. The bearings in my Lazer have lasted 2 years...the Losi bearings, maybe 2 heats.
What you're describing sounds like an X-Ray Multi-diff...you can make it into a "one-way spool". Not many people use that configuration in 4wd off-road (never heard of one myself). It's generally either ball diff, spool (solid axle), one-way or (on shaft cars) a center(shaft) one-way or a one-way center pulley in some belt cars, with either a spool or a ball diff.
I love front one-ways myself...great turn in and corner speed...much smoother.
10-16-2007, 10:48 AM
#8
I sold my XXX4 long ago but when I had mine I found a set of after market (trinity maybe?) titainium outdrive sleaves. You pressed the stock outdrive into the sleave then put in the outdrives like normal. This solved the problem of the out drives (& dog bones) poping out. It does not solve the oneway bearing failure though.
10-16-2007, 10:57 AM
#9
Thanks. That was a lot of real info all at once. So, do the Losi bearing break just because they are small, then -- and securing the shafts into there place will not absolutely solve the breakage problem? If securing the shafts would help, I was looking at securing a washer to the flat of each shaft (obviously there is a slight change in the order of assembling the unit back together) -- a washer just a bit bigger than could escape through the one-way bearing. Right about a single shaft being a "one-way spool".
10-16-2007, 11:10 AM
#10
In my book, it just comes down to the fact that the Losi one-way bearing is very, very small compared to standard one-ways used in any other car.
I've only had one one-way fail ever (nitro car, big impact) in anything besides the Losi. They need that bearing on the outside just to stabilize the outdrive...when that bearing comes loose, it pretty much destroys the one-way (sprag) instantly. Not that they don't die anyways, just that it's instant if the outer bearing comes loose. They really are a miserable little part.
Most cars just use a larger sprag and they don't need the extra bearing on the outdrive. The Apex (?) one-way used standard one-way bearings, so they would last forever, like any other one-way. The problem was that *if* you could find them, they were close to $100 to get one to the states. I tried to locate someone who could get a Tech Racing one-way, but I didn't have any luck...and it seems like it was a limited-run part...but I don't speak Japanese.
I'm starting to realize again why I bought my Kyosho Lazer...LOL...it comes with every diff combination in the box.
I've only had one one-way fail ever (nitro car, big impact) in anything besides the Losi. They need that bearing on the outside just to stabilize the outdrive...when that bearing comes loose, it pretty much destroys the one-way (sprag) instantly. Not that they don't die anyways, just that it's instant if the outer bearing comes loose. They really are a miserable little part.
Most cars just use a larger sprag and they don't need the extra bearing on the outdrive. The Apex (?) one-way used standard one-way bearings, so they would last forever, like any other one-way. The problem was that *if* you could find them, they were close to $100 to get one to the states. I tried to locate someone who could get a Tech Racing one-way, but I didn't have any luck...and it seems like it was a limited-run part...but I don't speak Japanese.
I'm starting to realize again why I bought my Kyosho Lazer...LOL...it comes with every diff combination in the box.
10-16-2007, 11:13 AM
#11
There are all kinds of tips on helping make losi one-ways last in tuning section of the X - 5 manual. The pages are pdf files, see them here and here. The most important of those tips is T9: grinding down the pins on the CVD's so they don't pull on the outdrive cup. Using these tips, I've only lost one one-way bearing since January in my X -5.
We at X Factory have actually tried a few different ways of securing the pins in the one-ways so they can't fall out, to no avail. Part of the problem is that those pins have to be extremely hard or else the rollers wear into them in no time, and the whole unit is destroyed.
If you don't mind doing some searching, you can find the physical one-way bearings that the Losi unit uses separately (from like McMaster or similar). Pick up like 4 of those, and then if/when a Losi bearing does go, you can carefully punch it out of the housing and push a new bearing back in.
The apex one-way and the Lesro units are pretty much the same things. The Lesro units are a little smaller overall - they use the same one-way bearings, so maintain the durability - and so they fit in XX4's and X - 5's much easier. You can see a pick of an apex unit here, info about the Lesro pulleys can be found here. Both these units are almost indestructible (no guarantees, but I've heard of one surviving a full speed run into a concrete wall...) but they are noticeably heavier than the losi units are.
Wow, that was longer than I thought it'd be! Hope that all made sense.
We at X Factory have actually tried a few different ways of securing the pins in the one-ways so they can't fall out, to no avail. Part of the problem is that those pins have to be extremely hard or else the rollers wear into them in no time, and the whole unit is destroyed.
If you don't mind doing some searching, you can find the physical one-way bearings that the Losi unit uses separately (from like McMaster or similar). Pick up like 4 of those, and then if/when a Losi bearing does go, you can carefully punch it out of the housing and push a new bearing back in.
The apex one-way and the Lesro units are pretty much the same things. The Lesro units are a little smaller overall - they use the same one-way bearings, so maintain the durability - and so they fit in XX4's and X - 5's much easier. You can see a pick of an apex unit here, info about the Lesro pulleys can be found here. Both these units are almost indestructible (no guarantees, but I've heard of one surviving a full speed run into a concrete wall...) but they are noticeably heavier than the losi units are.
Wow, that was longer than I thought it'd be! Hope that all made sense.
10-16-2007, 11:31 AM
#13
I actually tried drilling out the back side of the Losi half-shaft, but the metal was too hard for my drill bit. I was going to put a little screw in there holding on a little washer (slightly bigger than the shaft itself). I did try a run where I glued a washer back there (tricky not to hit the bearing with the glue), but it did not adhere long enough in that test.
Paul, one of the reasons I would like to fiddle around is that I have an X-5 on my mind. So any results would carry over. Of course, the eRC8 project would be an appealing option, too.
Paul, one of the reasons I would like to fiddle around is that I have an X-5 on my mind. So any results would carry over. Of course, the eRC8 project would be an appealing option, too.
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