Dravpnir tries to build something even lighter

[Dravpnir]

Originally Posted by BliB

Dude, think it's so awesome that a guy like you without any real knowledge to work with lathes and mills.
Buys a mill and start to learn cad/cam and start making your own gearboxes and stuff!

Been following your build since the RS10 (in the swedish forum) seeing all the great parts you've made!

You just keep surpricing with the flawless quality!
And everytime we meet you have the trunk full of stuff to show

Maybe we need to meet for pizza and beer sometime during the winter?

Thanks a lot for the nice compliments

I am a big believer in "learning by doing", so there is nothing to be afraid of to try new stuff. I am also quite blessed to be working where I do, to have a lot of talented colleagues to ask for help and not to forget the workshop in the basement that is free to borrow.

I started out quite modest with the modding of the RS10, but it wasn't after I bought the mill I could really start to mod like I wanted. I think the mill is probably one of the better things I bought the last couple of years

Pizza sounds good, if we skip the beer that is

Originally Posted by Calderwood

I have been working on the same idea as you have here, using plastic bushings at the tube ends. I'm not using delrin but it seems to be working flawlessly. The loads are very low at the ends of the axle compared to the loads the gears place on the shafts. Bravo sir!

Thanks

May I ask which material you use for your bushings?


And speaking of bushings. I have gotten a few questions about why my bushings look like they do. The ones in the pictures above is only semi-finished. Today I dusted of my mill and completed them. I need to tune the mill to some degree so the machine work is not the nicest, but the bushings are atleast fully functional now.



And mounted on the axle tube

[cabron]

can you combine the bushings with the link mounts? would that help with weight?

[Calderwood]

Originally Posted by dravpnir

thanks

may i ask which material you use for your bushings?

uhmw.

[SkaldidDog]

Looking nice.

One request, PLEASE don't include that ghastly Integy motor in any more of you lovely photographs. It hurts my eyes seeing that turd next to your beautiful creations.

J

[ClassiCutCustoms]

Hahahaha...... I am guilty of that too recently. Good suggestion.... Lol

[Dravpnir]

Originally Posted by cabron

can you combine the bushings with the link mounts? would that help with weight?

Not a bad idea actually. But I like to be able to change the bushings when the slop starts to appear, so I think I will make the lower mounts as a separate piece. But if it is so that it takes a long time before the slop starts to show, I might take up on that idea

Originally Posted by Calderwood

uhmw.

Thanks


Todays work



Nice and tight



Starting to look like a "real" axle now.



I choose to leave the screw to adjust the pinion mesh outside the box to make it easier to adjust the mesh.



A drawback when you got really thin axle tubes is that it looks so silly when the hex is wider than the tube



Weight of the rear gear box. This is with steel hardware, solid steel rear driveshaft, unmodified gears and no lower link mounts. By making my own titanium driveshaft, changing the hardware to titanium/aluminum and lighten the gears I should get down to around 120-125 g for the rear axle.

Originally Posted by SkaldidDog

Looking nice.

One request, PLEASE don't include that ghastly Integy motor in any more of you lovely photographs. It hurts my eyes seeing that turd next to your beautiful creations.

J

Originally Posted by ClassiCutCustoms

Hahahaha...... I am guilty of that too recently. Good suggestion.... Lol

Does this soothe your sensetive eyes

[ClassiCutCustoms]

Looking spectacular...... Keep it coming

[SkaldidDog]

Originally Posted by Dravpnir

Does this soothe your sensetive eyes

Ahhhh.

J

[Dravpnir]

Originally Posted by ClassiCutCustoms

Looking spectacular...... Keep it coming

Thanks

Originally Posted by SkaldidDog

Ahhhh.

J

I have been thinking a great deal about which motors to run. It ain't easy and there is not any clear choice. So, until something better at the same weight, or lower, comes out, I will stick to my old Jamara Cobalt 400 13T (same as HH 454 Cobalt Pullers). They work ok on 2s and the weight is really nice at around 107 g (3.8 oz) per motor.

These motors use a mounting distance of 16 mm and my gear boxes are made for ordinary 540-motors with 25 mm mounting distance... so some adapters will be needed and I made two prototypes today out of 2 mm thick aluminum plate. Also the first time I tried to make counter sunk holes with the mill.


Adapter mounted on the motor.


Mounted on the axle. I the end I think I will end up around 240 g for the complete rear axle including motor. So 1200 - 240 = 960 g to go

[SkaldidDog]

Man that baby just screams "chuck me into a rip-rap hole, bind me up and torque me out!".

J

[SlimsPalace]

Man these axles are sick! Can't wait to see the rest of it!

[ubbb69]

Dravpnir you do amazing work.

[Dravpnir]

Originally Posted by SlimsPalace

Man these axles are sick! Can't wait to see the rest of it!

Originally Posted by ubbb69

Dravpnir you do amazing work.

Thanks


It has been going a bit slow the last days on this build, but today I did get some things done.

I made some titanium shock shafts for the SCX10 shocks. I made the shaft 5 mm shorter as I understand (right hopefully) that you have to limit the shock externally when you are using a bladder.

I will save a total of 5 g for by replacing the stock shaft with the titanium ones in the 4 shocks.



The shock body comes from RC Bros, the spring cup is from JeepingDoug, the spring is the long Mini-T silver, Traxxas aluminum balls and the machined pistons from Axial.



Total weight for the shock including oil



As comparison, my old lathed Big Bores with Mini-T springs, JeepingDoug spring cups, cap-modded, Traxxas aluminum balls and titanium shaft weighted 10 g.

I also almost got the new titanium rear drive shaft completed. I only need to drill 3 holes and then it is ready for action. Weight, below 20 g

[ubbb69]

Nice work, everything looks killer.

[rofo]

Pure engineering porn

[pajey]

You would be the best mate ever haha. Really nice work. I love the amazing finish on everything. Very clean.

[Dravpnir]

Originally Posted by ubbb69

Nice work, everything looks killer.

Originally Posted by rofo

Pure engineering porn

Thanks guys

Originally Posted by pajey

You would be the best mate ever haha. Really nice work. I love the amazing finish on everything. Very clean.

Haha, thanks

It has been going a bit slow during christmas with this build, but I got some time to finish the rear drive shaft today. I also drilled out the little gears and saved almost 2.5 g.






Total weight for the rear axle excluding the lower link mounts. I also have switched out the aluminum hexes for some plastic ones. My goal for the rear axle at 240 g seems reachable. The larger gears can be lightened and I also have received a big pile of aluminum screws the will decrease the weight a gram or so.

[Dravpnir]

While I was ordering more carbon fibre tube for the spacers for my sporty I noticed that the same company sold a woven carbon fibre tube with the same outer diameter as the titanium tube and with a wall thickness of 1 mm. I just had to order a piece, because it would look so good for the rear axle



For the front axle I will be using the titanium tube. Do not trust CF tubes for the front with the strong servos we are using.

[Zarizi Tech]

Just found this build. Looking spectacular Tobias! Looks like we are in serious trouble in the Nordics!

[rofo]

Originally Posted by Zarizi Tech

Just found this build. Looking spectacular Tobias! Looks like we are in serious trouble in the Nordics!

The best part about Nordics is that it is actually a DRIVING comp