Re: Team 254 Presents: Dropshot Technical Binder 2016
 

We were very conscientious about only meeting those 4 days until week 6. We met more during the final week of build, went back to the 4 day schedule, and then did more like 5-6 as we got deeper into the season. We tried to make sure we left at 11 pm at the latest most nights, which we did a reasonably good job of during the build period and a less good job of as we got into competition season.

On the whole it was much better than previous years in which we worked 7 days a week the entire season, often until 2 am or later every Friday/Saturday.

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

What prompted you to do that? Change of venue? Mentor/student burnout?

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

It's not sustainable and you aren't very productive when you've been there that many days in a row for that long each day.

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

How was your experience lasercutting a bellypan from 1/4" thick ABS? I've read that ABS tends to curl and melt rather than vaporize under a laser.

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

This a question we get asked a lot and unfortunately we don't do a very good job of documenting this besides the build blog (which was largely incomplete and thus unlikely to be released this year).

I've attached a general timeline from 2016 of major subsystems (all times are for the end of that day/week). This was done mostly off of memory and the build blog was not consulted, so take it with a grain of salt.

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

I would love to hear more about the android app you guys used for vision.. thats such a cool idea

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

Awesome robot guys.

Will there be a build season blog released for this year?

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

Literally 2 posts above you...

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

We are throwing some fairlane wheels on our shooter for an offseason event in place of our colsons. Did you guys use round or flat safety wire and what was the rough OD or width respectively, as I would prefer not to guess and check through a series of McM orders. Thanks so much!

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

Whoops, I searched the page for "blog" and got no results, but I must have made a typo (on my phone). My bad :o

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

Can't speak for 254 but we've used ABS for several years now. We love the material but you are correct on the challenges of laser cutting especially at 1/4". That does not stop us though. We just run at a real low cut speed and get pretty clean cuts. Some cleanup is required.

For reference we use a WKLaser LC1280 which is a 150 watt laser. Going real slow we can make it through 1/4" ABS in one pass. Thinner material cuts without an issue.

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

Not on 254, but lots of laser cut ABS parts on my robot this year, most from 1/4". It's not too hard to do, but it takes a little trial and error. Multiple passes, playing with the feed rate and power level, and making sure your air / ventilation is good are all good steps to try. After some tweaking (approximately 1 practice robot worth of parts tweaking) it was pretty easy to get a quick and consistent part out of the laser cutter. This made manipulator fabrication quick and easy for us.

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

I may be mistaken but it doesn't look like there are CAMs on your bearing blocks to tension the chain. Did you tension chain or just find an optimal position that was permanent?

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

This is the same as last year. We did fixed center to center distance that was the nominal chain pitch plus some fudge factor (I think .015" ish added to each run, but I don't remember for sure off the top of my head).

Re: Team 254 Presents: Dropshot Technical Binder 2016
 

I know this has been discussed a lot but can you explain why this works? How does accurately getting the fixed center to center distance remove the need for tensioning? Is there less stretch? Or what about loose chain normally does require tensioning?