Kershaw Direct drive review

[marcus]

Ok. So I WAS going to make up a brushless Savage conversion but I wandered into my LHS last week and there sat a Flux. The guy who'd ordered it had bailed on them so they were somewhat relieved to be able to unload it on me

I'd already ordered the Direct Drive unit and a couple of battery boxes from Dan so they were coming anyhoo.

Well, I like the Flux and don't really have any plans to run a conversion as such, but here's what I think of the Kershaw gear which arrived yesterday anyway.

Direct drive unit

The Direct drive unit itself is a pretty simplistic device, the best things normally are though I guess. Assembly was OK although the instructions are rudimentary to say the least. Definitely need a more comprehensive set of directions.
There is an amount of shimming needed to centralize the gears with respect to each other and also to get them to clear the casing. Taking the instructions at their word gave me a totally locked gearbox

The Delrin spacers used to keep the gear casing halves separated is a cheap shot, should be alloy which won't compress as you tighten them up.

The CNC work is accurate but the finish is somewhat Raw. There are many marks on the metal where a drill bit was plunged too deeply when making holes, you can see two such marks on the pics behind the top side mounting holes. There are 9 such marks on the structure.

A problem I see which probably won't actually have much effect is that the gear casing WILL sit at a funny angle because the mounting holes were drilled whilst the unit wasn't straight. You can see what I mean in the pics, look at the two mount holes on each side.

Once I stripped it, threw the instructions and fasteners away and rebuilt it using my head and my fasteners, it was fine.

So long as the Delrin gear holds together i would say that this appears to be bullet proof. The meshing between the gears is spot on so I imagine they will have a long and happy life working together.





Battery Boxes.

Oh dear.

Honestly.... I feel a bit embarrassed for Dan here because I know he's a real nice guy. but these boxes really are astonishingly poor. I made them up but I knew there were going to be bad, and now they just sit here on my worktop flipping me off.
The instructions were bad, the fasteners are of the cheapest stock and ALL the wrong length.
I cannot find in me to recommend these things. Buy some decent Delrin jobs like Mike sells and make up a strap system yourself.

Come on Dan, ditch these things and get some Delrin boxes made up

[lincpimp]

Can you take some shots of the dd unit from the side so that i can see how the gears are attached to the shaft... They look like pinion gears with set screws. I am guessing the top shaft is a savage input shaft, and the bottom shaft looks to be custom made.

The al is cut with a water jet by the looks of it, and the fact those holes are not drilled correctly makes the hole unit crap. I would send it back to Dan and request your money back.

If the lower pinion is the same as the over size plastic pinions he sells for the emaxx (which come from sdp-si) it will not last. I stipped a few of those pinions in a bl revo conversion, with a 9l on 3s lipo geared for about 35mph.

The whole thing is cheap, and poorly made too. I will definately say that the 4 parts needed to convert a nitro savvy tranny into the flux tranny are a much better bet.

And those battery trays...wow.

[marcus]

Yea, they are held in place with a set screw and that is indeed a stock savvy input shaft, the lower looks to be custom

[lincpimp]

Did you really pay 150+ for this setup? The site says 99 for the dd and 51 for the trays... Ouch, send it back.

On the other hand, thanks for reviewing it for us. I am sure your review will save many people money in the long run!

I have purchased a few of Dan's products in the last few years and was never really all that impressed...

I just got my unit and I agree. It is disappointing. It looks like it was knocked out quickly without an eye to quality. The holes are off center and most of the holes still had burrs that needed to be filed down. Just wait till the Flux single speed starts arriving. So far it has proven bulletproof to me and it uses the stock Savage X case, so it will fit any version.

[lincpimp]

Originally Posted by marcus

Yea, they are held in place with a set screw and that is indeed a stock savvy input shaft, the lower looks to be custom

Wow, that is kinda poor... Metalman made something similar to this that was on a revo I bought from another member. It did have a center diff, and used a pinion gear to drive the diff. It was made by hand, and was much better

[lincpimp]

Originally Posted by Electric Eel

I just got my unit and I agree. It is disappointing. It looks like it was knocked out quickly without an eye to quality. The holes are off center and most of the holes still had burrs that needed to be filed down. Just wait till the Flux single speed starts arriving. So far it has proven bulletproof to me and it uses the stock Savage X case, so it will fit any version.

Only 4 parts are required to convert an X 2 speed to the single speed flux setup. Only the center shaft and gear change, along with a few washers and e clips. Really simple, can't wait till the parts are available.

[lincpimp]

Originally Posted by marcus

Yea, they are held in place with a set screw and that is indeed a stock savvy input shaft, the lower looks to be custom

How many teeth are on each gear? Just interested to see the ratio...

[doo540]

The internal gear ratio is 2.5 to 1. Thats not counting your spur/pinion combo. I believe the drilled holes that people are complain about in the sides not being drilled in the center of the aluminum plate are that way to level out the tranny when installed in the savage. If you look at the mounting holes in a stock savage TVP plate they are not in line up and down when the savage is at rest. Water jet will leave that type of finish on the edge, its still CNC controlled, its just not a "milled" edge. Setscrew in the gears dont bother me, remember we all use setscrews to hold our pinions on our motors, as well as the drive cups for diff pinions. If you want to add a little bit of safety to it drill a small hole (not thru, spot face) in the shaft so the setscrew can "seat" there.

[marcus]

Yea, DOO is right of course. I believe the offset mount holes are deliberate (Sorry Dan)

[doo540]

I thought the same thing on the holes untill I took a closer look at my savage XL.

The battery boxes: If you had better screws would that have changed your opinion? Or are the side walls to thin for you? I'm always looking for a better way to hold my lipos in my projects too.

[marcus]

The screws were too small, the side plates to shallow and wimpy the backplate half hearted and flimsy.

Another point, less important to some agreed, is that these things are Butt ugly. I won't spend $xx.xx on a Savage project so I could hang dangleberrys off the sides