Kodiak AEV 3 Armoured Excavation Vehicle

[AlwynTurner]

Hi Rob, it's all quite clear now thanks for the explanation. Re the arm weight, would it save much weight to switch to ribbon cable instead of wires (and possibly also be easier for cable routing)? Another thought re weight, is it worth considering 'honeycombing the arms by drilling holes in them and then covering with a very thin skin of styrene - thinnest you can find, that way you keep the strength of the arm but lose some of the weight and also don't have to reconstruct the arm? regards Alwyn

[HERMAN BIX]

I see where Mr Turner is going. The arm could(could) be done using the skeletal frame with an outer skin, but it must be a bummer to get the lot so right & not have the bloody motor lift the arm.
Is there any room for a counterweight to reduce the leverage moment on the pivot point to the lift motor ?

[wibblywobbly]

No way am I drilling holes in the thing. My current strategy is to reduce friction on the lifting arm, plus the replacement hotend for my 3D printer arrived today, so I am doing a few test prints to make sure that is all working ok. Once it is I 'should' be able to print some lifting arms that are more accurate than my styrene efforts, and do a more complex but more efficient design.

Fingers crossed....

[971wright]

Hi Rob could be you have a mechanical lock when the arm is at its low point, you may need to put and angle on the motor so its pushing at an angle instead of a parallel push,or another motor just to lift it slightly to give you the angle.

regards pete

P.S. there is an f14 on ebay with all the bells and whistles but its £200

[wibblywobbly]

Hi Rob could be you have a mechanical lock when the arm is at its low point, you may need to put and angle on the motor so its pushing at an angle instead of a parallel push,or another motor just to lift it slightly to give you the angle.

regards pete

P.S. there is an f14 on ebay with all the bells and whistles but its £200

There's another on there starting price £10? lol.

I will keep with my original plan, the idea of making all of this work using cheapie HL kit is what appeals to me, it's a bit of a challenge in my eyes. Bear in mind that the only factory made 1/16 scale version is £4k, I think I come in a bit below that.

I did a couple of test prints and the damned extruder clogged up again. Luckily this one didn't break, so I stuck it on a styrene dish on the cooker and managed to melt it all out, blooming house reeks now. I will give it another go when the bits have cooled down and see if I can actually print something useful.....

[wibblywobbly]

Every time I walked past this I kept looking and thinking about why the arm wouldn't lift??

I fitted three RX18's, three receiever boards, and played around with hinges and links...but it still kept jamming up. Then today I watched as the motor almost stopped moving altogether. I removed the arm and ran the motor...it would only go one way. Luckily I had a spare that I had ordered, hooked that up and the arm was back to moving like it was when I built it. All along it was a duff motor. Grrr..

So now it is back to aralditing the new motor in and the whole thing should be working as nature intended.

Then its just getting all of the receivers to work independently via a custom 3 way switch....and at this moment in time I have no idea whether the theory works...

[AlwynTurner]

Hi Rob, glad the problem turned out to be so simple to fix, I have experienced the same syndrome a few times and know how irritating it is to find that it was all down to a random gremlin that eventually was simple to fix! Good luck with the three-way switch, the theory sounds right, just hope it works. Following along with the build. Alwyn

[wibblywobbly]

Just to prove the concept...it went well until a wire came off the lift motor.

[AlwynTurner]

Awesome Rob, you just need to shoot those gremlins, they get everywhere! Alwyn

[mcevoyi]

Ohhh that a lot better and very impressive. ..