1:10 or 1:12 scale project wanted...

sweet man!

lol but ur not the first ;D

a guy at my local track has a converted crt.5, its sweet, i still would of dumped it for my cyclone, but its awsome! hes using a mm 5700kv, and a 2 cell lipo

he isnt on the fourms but i need to get him here so u guys can see it! buts its sweet!


jw, sorry if u already said this but what motor are u going to keep running?

[BrianG]

Thanks! I didn't didn't intend nor think I would be the first to convert a CRT.5, so that's no biggie. Actually, I like to look at other conversions to see how things could have been done differently/better/etc.

I'm planning on using the 4600 on 2s lipo. I like the slower motors. :)

And yes, you MUST get him here. That's not a request... ;)

[Serum]

I like it so far!

I bet it will be a fun ride!

Why didn't you made the motormount of perfect 90 degree stock aluminum (without the round corner) so the motor sits on the bottom of the lower plate? it gives it a nice stability.

Allthough you would need two straight slots to move the motor instead of 1 round slot with 1 hole.

[BrianG]

Three reasons: 1) I already had the stock, 2) when I ordered the angle, the only thing available in 6061-T6 at onlinemetals was the one with the rounded corner, and 3) I wouldn't be able to use stock screw locations to tie down the mount to the chassis because the motor would hit the screw ends.

And yes, I would have to "machine" two slots instead of one (and one was bad enough!). Even so, there is virtually no flex in the mount, so I think I should be fine.

Originally Posted by BrianG

Thanks! I didn't didn't intend nor think I would be the first to convert a CRT.5, so that's no biggie. Actually, I like to look at other conversions to see how things could have been done differently/better/etc.

I'm planning on using the 4600 on 2s lipo. I like the slower motors. :)

And yes, you MUST get him here. That's not a request... ;)

yeh his pulls wheelies with a center diff:004: :018: :017: :028: and she just flat out huals!!!!!!!!!!!!! urs looks alot cleaner tho, lol u did the motor mount very well, i guess after u have done so many they get simple a? lol it looks almost perfect

[BrianG]

Lol, never simple, but they are getting easier since I've done a couple of them. My conversions are usually clean becauseI figure if I'm gonna go through the trouble of doign it, why not do it right. :)

[Serum]

Brian;

point three; doable; flush the screws to the top, and use red loctite. Nitro engines are held down the same way.. And they shake like crazy..

1 and 2 are not arguable.. :)

[BP-Revo]

Actually...I've never locktighted a single part around my engine assembly...(knock on wood) - nothing has happened...

[BrianG]

I don't have much luck with tapping threads into aluminum for some reason. Plus, being only 3.5mm 6061, I'm concerned about the threads holding up. At any rate, I don't want to rebuild the mount simply to have tapped holes. :) The top of the motor doesn't even go as high as the top of the diff mount so it shouldn't be too bad. If anything, I'm more worried about my batteries because they are going to have to sit in there edgewise to fit, which will make them quite tall...

[gixxer]

thats looks awesome. looks like you will have just enough room for the 5000mah cells too. I just saw one of these in person yesterday for the first time(test for rcdriver). First thought was converting, but didn't know if there would be enough room for the battery.

I would like to stay with 2s so that way I can use the same pack as my MF2. I will definetly be checking to see how the mamba works for you and if the kyosho gears will work. If they do then I think this will be my next car.....

[rchippie]

Brian i like what i see .

[BrianG]

OK, bad news. :007: The Kyosho spur physically fits, but is quite a bit too thick to fit the diff holder. The steel spur is formed differently to be as thin as possible - way thinner than the Hyper 8 spur for example. Not only that, but the existing diff doesn't use your typical sized bearings. The stock bearings are 15x10x4 (OD/ID/W) compared to whatever size the typical diffs are. So, my choices are:

1. Try to find bearings that will fit the stock mount with the Kyosho diff. I would need 15x8x4 (od/id/w) bearings, which I cannot find for some reason, not even at Avid. If I go with this plan, the diff mount has to be moved back a little (not a big deal) and I'd have to modify the Kyosho spur since the diff outdrive is too short to go all the way through the Kyosho spur and still be able to use the retaining pin (inside the diff).
   
   
2. Keep using the existing diff with the steel spur, get a steel pinion, and take my chances with the wear. However, 1/8" bore Mod1 pinions are not available anywhere.
   
   
3. Get a regular center diff with mount (although I think I can use the stock mount from my Hyper 8), install the Kyosho spur, and remake the motor mount.

Neither of these options is very appealing, but #3 sounds like the best bet from a part availability standpoint. Option #2 sounds like the easiest, but the pinion is not available and I'm not sure on the steel-on-steel idea.

Any suggestions or other alternatives?

[rchippie]

Originally Posted by BrianG

OK, bad news. :007: The Kyosho spur physically fits, but is quite a bit too thick to fit the diff holder. The steel spur is formed differently to be as thin as possible - way thinner than the Hyper 8 spur for example. Not only that, but the existing diff doesn't use your typical sized bearings. The stock bearings are 15x10x4 (OD/ID/W) compared to whatever size the typical diffs are. So, my choices are:

1. Try to find bearings that will fit the stock mount with the Kyosho diff. I would need 15x8x4 (od/id/w) bearings, which I cannot find for some reason, not even at Avid. If I go with this plan, the diff mount has to be moved back a little (not a big deal) and I'd have to modify the Kyosho spur since the diff outdrive is too short to go all the way through the Kyosho spur and still be able to use the retaining pin (inside the diff).
   
   
2. Keep using the existing diff with the steel spur, get a steel pinion, and take my chances with the wear. However, 1/8" bore Mod1 pinions are not available anywhere.
   
   
3. Get a regular center diff with mount (although I think I can use the stock mount from my Hyper 8), install the Kyosho spur, and remake the motor mount.

Neither of these options is very appealing, but #3 sounds like the best bet from a part availability standpoint. Option #2 sounds like the easiest, but the pinion is not available and I'm not sure on the steel-on-steel idea.

Any suggestions or other alternatives?

Brian try looking here.

http://bocabearings.com/main1.aspx?p...esearchbearing

[BrianG]

Sadly, niether Boca nor Avid has the size bearings I need.

I spoke with glassdoctor a little while ago and he wanted some pics, so here they are:

This image shows the insides of the various spurs. From top left: CRT.5, Kyosho, and Hyper 8. Right away you can see the CRT spur is shaped differently and has less depth.



This image shows the top view and you can see the bumped out part of the CRT diff that makes it so low profile.



This one shows the difference in collar size/depth.



This one shows one of the outdrives and how short it is. This is why it won't fit on the Kyosho spur. If I shave enough off the Kyosho collar for the outdrive end to reach the other side, there isn't enough room for the bearing. I can't use a regular 1/8th scale outdrive since those are made for much larger dogbones.



There is no O-ring in the diff, just this plasticy gasket. Maybe this is why there are reports of leaks? I replaced it with 2 of the Ofna paper gaskets.



This one shows that even when the collar of the Kyosho spur is shaved down, the other end of the outdrive is still too short. Any more shaving and the bearing on the collar won't fit.



This one just shows the stock bearing on the Kyosho. Doesn't fit well obviously. :)



Hope this helps you visualize what I was talking about glassdoctor...

[BrianG]

OK, how about this for thinking outside the box. I trimmed out the inside of a 44T spur and press fitted it on the diff case. I just don't know what to use the secure it there without it slipping. Maybe drill some pins into both spurs? I want to be able to replace the spur if needed...