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Re: Scrambler B
Posted: March 15th, 2016, 9:19 am
by InfiniCuber
GoofyFoofer wrote:Does anybody have any winning scores from any competition? I want to see about what is needed distance-wise for a gold. Of course, every competition is different, but a general score range would be helpful. Thanks!
Well, this depends on competiton more than you think. Mostly level of competition. Are you asking for gold at an invite, regionals, state, or nationals? Nationals would be between 0-15cm with a 2 second time or so, for a competitive state and some competitive invites i would say similar distance maybe 0-20cm with about a 2.5 second time, and regionals and less competitive invites more so. Those are ranges for possible medals imo, someone else could think different.
Re: Scrambler B
Posted: March 15th, 2016, 9:28 am
by Eggo
GoofyFoofer wrote:Does anybody have any winning scores from any competition? I want to see about what is needed distance-wise for a gold. Of course, every competition is different, but a general score range would be helpful. Thanks!
I think we're both competing at Socal State, so I would say around 10-25 cm off with a time of less than 3.5 seconds.
Re: Scrambler B
Posted: March 15th, 2016, 9:34 am
by Opie
bernard wrote:sciencecat42 wrote:bernard wrote:Uploaded pictures of last year's device. Some of the pictures are inconsistent (e.g. angle changing mechanism for bonus shown in fourth and fifth pictures aren't on other pictures of the vehicle as that was added later). And the mass isn't shown. Feel free to ask questions, borrow design (I certainly didn't come up with all the ideas to this myself), etc.
scioly.github.io/scioly/scrambler
What are the things between the plastic axle containers and the wheels? Ball bearings?
Also, how did you attach the long dowel rod holders to the axle containers? Screws or was it printed like that?
They are wheel hubs that attach wheels to axles. The wooden dowels were sanded down until a tight fit was achieved. No glue was necessary except for the backstop attachment.
Where did you get the Wheel hubs? I can't find them online. Thanks.
Re: Scrambler B
Posted: March 15th, 2016, 9:39 am
by bernard
Opie wrote:bernard wrote:sciencecat42 wrote:
What are the things between the plastic axle containers and the wheels? Ball bearings?
Also, how did you attach the long dowel rod holders to the axle containers? Screws or was it printed like that?
They are wheel hubs that attach wheels to axles. The wooden dowels were sanded down until a tight fit was achieved. No glue was necessary except for the backstop attachment.
Where did you get the Wheel hubs? I can't find them online. Thanks.
They are from Servocity, which also sells the wheels and axles I used. If you're using a threaded rod for one axle, you'll likely want two different sizes of hubs. And be pretty certain about your setup before sticking things together, since I've had axles stick to hubs.
Precision Disk Wheels:
https://www.servocity.com/html/precisio ... ug50MdlnVo
Wheel Hubs:
https://www.servocity.com/html/0_770__s ... ug5_8dlnVo
Shafts:
https://www.servocity.com/html/shafting.html
Re: Scrambler B
Posted: March 15th, 2016, 9:47 am
by Eggo
Ah! Someone else who uses ServoCity. I made my ETV out of the aluminum channels and the orange precision disk wheels. Also used the bearings from there.
Re: Scrambler B
Posted: March 15th, 2016, 10:16 am
by Opie
Thanks. Did you use any type of bearing, or did the axle just free spin in the frame?
Re: Scrambler B
Posted: March 15th, 2016, 10:32 am
by bernard
Opie wrote:
Thanks. Did you use any type of bearing, or did the axle just free spin in the frame?
I found that it spun longer without bearings, so I did not use any.
Re: Scrambler B
Posted: March 15th, 2016, 10:35 am
by sciencecat42
Opie wrote:
Thanks. Did you use any type of bearing, or did the axle just free spin in the frame?
Also wondering the same thing. Wouldn't the axle rotating against the plastic cause a lot of friction?
And when designing the parts to print, would it be advisable to make the holes for the dowel rods and axles a little larger so the axles/rods can fit through?
Re: Scrambler B
Posted: March 15th, 2016, 1:15 pm
by bernard
sciencecat42 wrote:Opie wrote:
Thanks. Did you use any type of bearing, or did the axle just free spin in the frame?
Also wondering the same thing. Wouldn't the axle rotating against the plastic cause a lot of friction?
And when designing the parts to print, would it be advisable to make the holes for the dowel rods and axles a little larger so the axles/rods can fit through?
I started out thinking I need bearings, and when I tested with quarter inch axles, I found that the wheels spun for longer without bearings. Without bearings my times were low, too.
I designed my holes to be the exact size (0.25") of the dowel but they printed slightly smaller, so sanding the dowel was necessary for some. Since I didn't print these myself, I was lucky the holes were not larger or I would have had more difficulty fitting the dowel in.
Re: Scrambler B
Posted: March 15th, 2016, 9:58 pm
by GoofyFoofer
Thanks for replies.
Also, are we allowed to clean off the track in any way prior to running our devices?