Dadio's 3D Printing Stuff

[Dadio]

More irritatingly over priced re-selling
https://www.ebay.co.uk/itm/175473161769?hash=item28db03f629:g:OKUAAOSwq9VjYVeF&amdata=enc%3AAQAHAAAA4GKJq6Jvogbuvv1O3Rl89VRjLaiBpUuhR0JSCyoY4BihOVSt9%2FCCfA7oXXPJ6hQ4mnfGds8hiqnPxbUMf%2FX106jKvUHdKcfe%2BrgimM1MOO7UFjGLLSOuJMg51iuKANOItw7abQjZnP5UwN9l00PVS%2BAeOetwRpHpO3GVz%2FnL93FgLTo%2BoqfDCXnkxh89fHqiJDkjrHjXmOMZyuYCIsbOwWZ0RAVyXpyPCHfiHeQ4WD41xBQMliyqD6hAuCwN%2FFvQOyN9jgYWgv079uwE9hFzI%2Ble%2FgIVSsh4IhEowIYzm33s%7Ctkp%3ABFBMyLLM3Ilh
And my Shapeways shop price
https://www.shapeways.com/product/569DNJJJZ/yokomo-dogfighter-yz-834b-gear-cluster?optionId=255344831&li=marketplace
I find it hard to believe anybody would spend that much on genuine 834b gears

[Frankentruck]

Interesting. I occasionally buy used parts from that seller.

[threesheds]

I know the guys gotta recoup cost of printer etc, but not all on one part!!

[threesheds]

The hirobo 12mm hex problem.
Curiosity I bought some cheap tamiya hpi axles. Then some 10x15x4 bearings to fit the cup of the axle. Can't find 5x15x5 to fit the narrow part of the axle but used 6x15x5 zerda with some spacer (rolled plastic for the time being).
Offered up to zerda steering knuckle to compare dimensions.
And if the recess for bearings was deeper and the face of the knuckle built up to accommodate 9mm bearings width..would it work? Wondering about shortening effect on dogbones or what other factors in the way.

The bearing recess is 5mm so 4mm needs to be found for the other bearing and I thought 2mm deeper recess an 2 mm added to the face of the knuckle.
Thoughts?

[threesheds]

The 11mm widest part of the cup of the tamiya axle fits so snugly into the knuckle it's almost like a bearing and some relief achieved by sanding the knuckle

[Dadio]

If your using Tamiya axles it's pretty easy to make up a bearing carrier that can take two stock size Tamiya bearings and be retained by the two stock bearing retaining screws , there's plenty of meat on the back of the knuckles allow them to be opened up for the larger drive cups , only take a few min to draw up , it would extend outward not inward so no loss of dog bone clearance .

[Dadio]

If your using Tamiya axles it's pretty easy to make up a bearing carrier that can take two stock size Tamiya bearings and be retained by the two stock bearing retaining screws , there's plenty of meat on the back of the knuckles allow them to be opened up for the larger drive cups , only take a few min to draw up , it would extend outward not inward so no loss of dog bone clearance . Be very similar to the ones I did for the Coyote.

[Dadio]

This is designed around Hot Shot axles as I had them to hand .

[threesheds]

I'll get a pic of an assembled unit and check the dogbone clearance as I think the tamiya needs to go a bit deeper into the knuckle .

[threesheds]

Looks like no tolerance to set the bearings deeper without affecting the dogbones and would have to extend outwards. It could be a 4mm extension that would be fixed with longer bearing retainer screws. What I wonder then is how wheels and steering might be affected with any changed position relevant to the kingpins or doesn't that matter. (Wheel offset etc.)
Maybe I should cobble an extender with a bit of kydex and longer screws just to see if it would work. And do more comparison of wheel alignment relevant to zerda original wheels.
Also I've got two different hex adapters of different depths/thickness so several variables.

[Dadio]

Ideally the pivot of the steering should be in the centre of the wheel , if it's designed that way in the first place then if you increase the offset with extending the hex hub further out then you should then use wheels with an offset that corrects it , in the real world unless your a pro driver you won't notice it and with a Zerda or 44b then the steering is so far from perfect geometry with the track rods odd length , angled steeply and with that type of servo saver that your really not going to notice 4 or 5mm .

[threesheds]

Ideally the pivot of the steering should be in the centre of the wheel , if it's designed that way in the first place then if you increase the offset with extending the hex hub further out then you should then use wheels with an offset that corrects it , in the real world unless your a pro driver you won't notice it and with a Zerda or 44b then the steering is so far from perfect geometry with the track rods odd length , angled steeply and with that type of servo saver that your really not going to notice 4 or 5mm .

I've done some comparison of offset with a mocked up knuckle with two bearings and looked at the alignment of the kingpin hole. Strangely the zerda setup of original wheel seems to have the inner edge of the tyre aligned with the kingpin and the GV beagle has the same. The mocked up knuckle with a 12mm hex wheel would have that same alignment. By pure accident my cobbled together 12mm hex adapter and cheap wheels did achieve alignment of the king pin with centreish of the tyre.
Bottom line is would you give me a rough idea of price for four hub/steering knuckle extenders? I'm envisaging just 4mm of the bearing holding part of the knuckle with the screw holes and use longer screws to retain the bearing and extender.
I'll do a rough sketch if it helps.
This would be just if you feel like doing it as a curious exercise.
Might be a futile attempt to remove some wobble of single bearing hubs. And the snug fit of 11mm cup of the tamiya axle I'll test just sanding out enough knuckle to allow free running with a bit of grease almost like a third bearing.
Bws

[Dadio]

Happy to do it for £10 for a set of 4 plus postage , I think I understand your idea , I just make an extension of the knuckle end outer profile with larger holes for longer screws and offset the double bearing placement to 4 mm outward so the drive cup sits within the knuckle on the inside . It will only take a few min to design and it's a small print , what spacing do you need between the bearings , I'm thinking 2mm ?

[threesheds]

Very fair thanks. As the bearing outer rings are about the same thickness there doesn't seem to be any fouling or friction but maybe 0.25-0.5 mm extra on the extension or I'll just add a shim.

[threesheds]

Another factor in this zerda axle experiment.
As I can't find bearings with 15mm outer and 5mm inner I got 5x10x4 which fit inside 10x15x4 so I've got options of trying the 6x15x5 zerda bearings with some spacer material making 9mm wide bearing or 8mm using 4mm bearings combo.
I can see I'll be tinkering with shims or spacers.