4 gear gear boxes, available NOW

[rcjunky]

I thought I'd post a link to 4 gear gear boxes for the atomic carbon CR2 or any other mid motor losi. The quality of them is amazing and you will not be disappointed. He makes them in batchs so when there's non left in his store, check back often until more are available. Best of all they're only about 35 pounds shipped.

http://cgi.ebay.com/PSI-Racing-4-gea...item4cf26ca9a2

[DerbyDan]

I'm looking forward to receiving mine.... studying the photos, I think I may have to shave a little off on the front of the gearbox to get it to sit neatly over the 'T' peice, but other than that it should be all good... will let you guys know how it works out

[rcjunky]

I should be getting mine in a few weeks as well, should be sent out today. If there is any issues, contact me or the seller direct and we'll see what we can do

[crashingbird]

how 'bout a geardiff version ?

Is there interest for such a version ? (= maintenance free midmotor fun !)

[rcjunky]

To my understanding there will be a gear diff version. There has been some interest in the us and I'm sure theres plenty on interest over the pond. I think Chad has a gear diff and is working on a gear diff version, that along with a sc losi conversion (the buggy and truck are done, the sc has a delema, do you make a conversion for the losi xxx-sct or the xxx-t as originally planned, or both...) I'll try to keep everyone posted when the gear diff version is done

[DerbyDan]

I got mine through the other day... amazing delivery considering I've only just also recieved the XX wishbones that I ordered Via ebay U.S a month ago!

Mine is one of the first batch of white cases & the machine work looks 1st class, i'm sure I will have to make some small adjustments to get it to fit right in the CR2 chassis, but i'm very pleased

[Legacy555]

Hi all,

I've bought one of these and used it on indoor carpet for the first time last night. Firstly, the casing needed quite a bit of finishing to get it into the CR2. The casing was about 1.5mm too wide, so bolts through to motor plate didn't reach, and the brass bracket to the chassis didn't line up. I used a sanding block to take the back face of the casing down.

With the 4 gear assembly, the motor can sit further back in the car as you can now mesh onto the spur instead of an extra idler. I found this has reduced the "edgy-ness" (inventing words now ) of the front end on carpet.

I'd recommend the gearbox casing, but be aware that it's not a plug'n'play item - may need a little work first.

[rcjunky]

could you post some pics of these mods? I'm surprised its too wide considering he did all his testing on a mid motor losi, unless the CR2 is that much differant. Mine should be here in 1 - 1 1/2 weeks so I'll report back.

[rcjunky]

I've seen pics of the gear diff version, it is done and ready for testing, stay tuned.

[rcjunky]

Just another little update. Chad is doing a pre order for the first 10 gear diff trannies tomorrow and the shipping date will be November 6th or earlyer. He now should have a programe for the ball diff version modified for the CR2 so it now should be bolt on and if you ask him he can do the same for the gear diff version. He can be contacted on rctech.net as 2wdmod and I'll try to get his email address for yall

http://www.rctech.net/forum/electric...ml#post8112937

EDIT: you can email him direct at [email protected] you can email him to preorder your gear diff tranny and probably also be put in line for the next batch of ball diff one.

[rcjunky]

Thought it deserved a new post, but both versions are now available to pre order and will require no mods to fit in the CR2 as long as you contact him saying so. You guys wanted gear diff 4 gear gear boxes, now you have them.

http://stores.ebay.com/Mid-Motor-R-C

[DerbyDan]

Originally Posted by Legacy555

Hi all,

I've bought one of these and used it on indoor carpet for the first time last night. Firstly, the casing needed quite a bit of finishing to get it into the CR2. The casing was about 1.5mm too wide, so bolts through to motor plate didn't reach, and the brass bracket to the chassis didn't line up. I used a sanding block to take the back face of the casing down.

With the 4 gear assembly, the motor can sit further back in the car as you can now mesh onto the spur instead of an extra idler. I found this has reduced the "edgy-ness" (inventing words now ) of the front end on carpet.

I'd recommend the gearbox casing, but be aware that it's not a plug'n'play item - may need a little work first.

Interesting..... I haven't actually got round to fitting the box onto my chassis yet - the projects on the 'back-burner' a bit at the moment & its not helping with the fact that i'm doing the XXX rear end conversion at the same time - so there's bits everywhere!

One thing I noticed with mine is the fact that the part that slots into the shock mount is too wide also - did you find this aswell Legacy555?

Also I see that the one now shown on PSI's ebay shop, now comes with a GRP spacer - I wonder if this is due to limitations with available plastic thicknesses? Or is it something that they've found that it needs to work better??

[rcjunky]

to my understanding the spacer is only for the gear diff as the diff is wider its too wide for the delrin, so he just makes a G10 spacer instead of trying to get thicker plastic. Chad now know what he needed to change to make it fit the CR2 and now they are differant then the regular version. Contact him and he may be able to swap them for you so it would just be bolt in. The other solution would to just buy his chassis conversion

[Legacy555]

Originally Posted by DerbyDan

Interesting..... I haven't actually got round to fitting the box onto my chassis yet - the projects on the 'back-burner' a bit at the moment & its not helping with the fact that i'm doing the XXX rear end conversion at the same time - so there's bits everywhere!

One thing I noticed with mine is the fact that the part that slots into the shock mount is too wide also - did you find this aswell Legacy555?

Also I see that the one now shown on PSI's ebay shop, now comes with a GRP spacer - I wonder if this is due to limitations with available plastic thicknesses? Or is it something that they've found that it needs to work better??

No, I had no problems with the piece that fits into the shock tower.

[crashingbird]

Originally Posted by rcjunky

to my understanding the spacer is only for the gear diff as the diff is wider its too wide for the delrin, so he just makes a G10 spacer instead of trying to get thicker plastic. Chad now know what he needed to change to make it fit the CR2 and now they are differant then the regular version. Contact him and he may be able to swap them for you so it would just be bolt in. The other solution would to just buy his chassis conversion

Most CR2-owners use the old style BK1 pivot, wich is narrower than the CR version.
We have at the moment the losi DT gearbox with the BK1 pivot, and had to cut a lot of material out of the pivot, but it's weakend a lot now....and it's still not even a perfect fit yet

Will the underside of the PSI geardiff-gearbox fit in the BK1 pivot without extra modification?
Are the holes for the 2 screws at the underside predrilled and tapped ?
And is this thread at least as strong or even better than an original Losi-box? (bit of a weak point if used a lot)

Perhaps Chad can make a customised pivot too ?

[Dr_UpGrade]

I've got one of the new internal idler gearboxes and run it on one of Chads PSI mid-motor chassis, and I run the narrower pivot mount with no issues.. After seeing Chad's thread on RCtech I think the issue of using the internal 4 gear tranny on the atomic is the 'front' screws mount where he initially made it for his own chassis where there is no 'lip'. I understand that he's already changed the CAD design specifically for atomic owners to make room for the lip..

Will be running the gearbox on friday at taplow so will let ya' know how it goes...

[rcjunky]

I'm not sure about the rear pivot block, I know it fits in the stock CR one as in his chassis, there already is sooo much steering no one runs the narrow pivot set up, but for the CR2, I'm not sure, email Chad as he probably has the stuff to find out for you. The PSI tranny should hold screws better as it is delrin which is harder then stock so that shouldn't be an issue.

[DerbyDan]

Originally Posted by Legacy555

Hi all,

I've bought one of these and used it on indoor carpet for the first time last night. Firstly, the casing needed quite a bit of finishing to get it into the CR2. The casing was about 1.5mm too wide, so bolts through to motor plate didn't reach, and the brass bracket to the chassis didn't line up. I used a sanding block to take the back face of the casing down.

Just been playing around with it tonight... and as you say the casing is a little too wide as you describe. One quick question, how much did you sand off in the end? I reckon that on my gearbox, if I shaved off 1.5mm it seems you need, I would be through past the ledge that the layshaft bearing sits against - losing the location for the whole layshaft?

I also mocked-up the XXX rear end set-up with that gearbox, all looks ok with that although I understand the BK1 rear end is even narrower, looking at how much material i'm going to have to remove off the chassis just for the Triple X pivot I would be wary of fitting anything narrower for fear of weakening the chassis too much!

Edit; Actually I think the Triple X & BK1 pivots are the same?? .... Not sure

[PaulUpton]

Dan try not to take any off the chassis when fitting the narrower block, i managed to rip a screw out of mine on sunday, so had to get a new chassis.

[DerbyDan]

I saw that Paul on Facebook.... not good

I must admit I was looking at my old TripleX, (with the same back-end arrangement) the width of the rear plate is the same as the AC chassis, so apart from maybe chamfering the edge a bit, I don't see the need to trim that part down? The 'T' peice on the other hand, does need cutting out to clear the front of the wishbones. The shocks limit the droop more than we expect I think - the wishbones don't drop down much further than horizontal.

I've been mocking up the gearbox to see what needs doing to get it to fit 100% - I've clearanced the rear tower (shaved off a few thou with a scapal blade) & now it sits snug over the trans housing. As Legacy555 has done, I will also need to thin down the motor plate mounting face - i'm going to take off as much as I dare without breaking into the layshaft bearing pocket, but i've got some spare long 4/40 screws, so I might, if need be, have to thin down the brass L bracket to get the hole to align & cut down the spare screws if the originals still aren't long enough to reach through the gearbox. I think this extra thickness is a bit of a manufacturing error - the PSI chassis is designed to use a standard idler equipped Losi box just like the CR2, with the extra offset of the motor plate from using the PSI 4 gear box the slipper back plate is pretty much virtually touching the motor plate.