We’ve mentioned the guys from Apex Buggy a couple of times in the rolls reports. They are a group of mostly freshmen, mostly living in a new dorm called “The Residence on 5th” or “The Rez” for short. Despite being on campus for only a few months, they’ve done an impressive amount of work towards starting a team including soliciting design and build advice from anyone that will talk, and doggedly seeking funding from private donations, and the various official channels. They are also the organization that recently inspired us to once again consider making seed grants to new orgs (see the New Org Grants thread in our project zone), a discussion we haven’t yet concluded.
Anyhow, they’ve secured enough funding to get going and they’re currently planning their first build for the winter months. Now’s our chance to help out. Apex front-man Connor e-mailed me asking some specific questions, but I’d like to use the opportunity to generally improve our informational resources for new teams. If you’re reading this, you know a thing or two that could help a new team. Take a moment and either:
- Edit one of the Reference pages below to share generally-useful buggy info with the community
- Email info@cmubuggy.org with tips or suggestions and we’ll do the ground work of sharing them with Apex and adding them to the Reference section
- Email Apex’s front-man Connor directly (cmhayes@andrew.cmu.edu) if you want to get your advice straight to the customer
- Post a comment on this post with your favorite tip or trick for building a buggy or getting to raceday with limited funds.
- “At the moment we need carbon fiber, a vacuum pump, and a vacuum bag. Those are the big 3
things to get started. Do you know any alumni specifically who could help us get those materials for good prices?” - “If there is anyone out there who wants to talk to us about carbon fiber, lay-up schedules, directional weaknesses, twill vs straight weave and all of that stuff it would be greatly appreciated.”
Reference Section pages to work on
These pages are just beginning. Anything you can add in terms of which tools and materials are most important, good suppliers for critical materials, or cheap and clever substitutes for expensive specialty tools and materials would be super helpful!
Good luck Apex, hope to see you out in February.
tommyk says:
Real vacuum pumps are expensive, so for about 3-4 years Fringe built buggy after buggy with a hacked craftsman compressor as a substitute. Switch the intake/outtake on the pump, route it through the tank, add a pressure gauge … you won’t get as much pressure or epoxy/fiber efficiency as with a real vacuum pump but sometimes that’s ok. Especially with early builds as you figure out the details of mold and layup crafstmanship and the tricks that make a wrap go smoothly to avoid critical and costly mistakes. (the best bag and the most pressure you can achieve with a premium vacuum pump might exceed your mold limitations if it is poorly designed).
Plain nylon is a cheap alternative to genuine a peel-ply with impregnated mold release.
Old blankets make just fine bleeder, just avoid the ones with lots of pubes, nobody likes a fuzzy buggy.
Don’t overdesign your first effort shells and plan on multiple builds to get to a high-performance model. This is an important financing strategy too, get the most of out your first wave of capital by planning for more than one build, hopefully at least 2-3 buggies worth. I havn’t shopped for cf for a while but this seems pretty cheap http://www.surpluscomposites.com/classified/k-plain-weave-carbon-fiber-fabric-listing-176.aspx –
vague memory seems to recall 15-20yrds of 50″ would result in a buggy with 2 layers inside and outside of a suitable core material plus a little extra where it counts (attachments, harness clips, safety areas). Forget if that included a composite bar or not … starting with an aluminum airfoil is kind of a no-brainer to keep the build simple (and cheaper).
Sam Swift says:
I even remember doing wraps on small parts with the compressor we stole out of a mini-fridge. It seemed like less of a genius idea when we wanted to keep beer cold later, but the wraps worked well enough.
the cook says:
you can find many fine vac pumps on eBay or at HGR suplus for under $100, so no need to hack a compressor. the hacked compressor will tend to fill the air with nasty oil vapor and overheat so that is a bad choice. I bought a brand new Boeckel vac pump on eBay for $75, new cost probably at least $1500, so all it takes is some looking. get one that looks like a “welch duo-seal” they resist fouling for years if you change the oil after a build, and are powerful enough that you will want to make a regulator valve to avoid crushing your foam
what tommy said with regards to peel ply but it is rayon not nylon. heavy fiberglass cloth makes an especially fine bleeder cloth. for smaller parts clear 2 mil polyethylene will make a good vac bag, but for a whole shell, the tubular commercial bag film can’t be beat – you don’t want to risk $1000 of materials with a bag leak
don’t pay extortionate prices for wax and PVA – mother’s carnuaba wax and extra hold aerosol hairspray work just as well
use cheaper polyester or vinyl ester for molds IF you have a place to work where the fumes are OK. never use anything but epoxy for the buggy itself
use slow curing, low viscosity epoxy. this will give you time to panic, fix it, panic, then fix it and still be OK. work in an area below 60 degrees if you can, but prepare an area over 80 degrees or raise the temperature of the same room after the bag is applied. some really slow epoxies need more temp and set stronger, but for your first go you don’t really want to build an oven I don’t think. expoxy will bond fine to previously cured layers if you either use peel ply or sand to cut the amine blush off the cured surface. consider working with less than the full body at once, and bond the pieces together
the cook says:
one more, consider making a 1/4 scale model
DeVos says:
I second this recommendation, especially if this is your first exposure to composites layups. (I would actually recommend doing 3-4+ experiments before you start the real build. Start with wrapping some foam with fiberglass, maybe work on a fairing mold, model buggy, and then the pushbar before getting to the shell.) This lets you get familiar with curing times, material properties, layup techniques and process while minimizing the effect your mistakes have on the final product. It also has the nice side effect of leaving you with a miniature buggy to display.
tommyk’s link is a pretty decent price. A couple of things to note: check to make sure that your supplier actually has the items that you order in stock; nothing sucks quite as much as not being able to start your build because your carbon hasn’t arrived. Also, if there is an option to guarantee that the roll that you purchase is continuous, it’s probably worth the upcharge so that you don’t need to worry about having cuts in inappropriate places.
Make sure you get safety goggles and respirators. It’s not the most healthy thing to take a shattered cutoff wheel to the eye or be sneezing blue snot after painting. If nothing else, you can point to them when your mom asks if you’re being safe.
the cook says:
take 3 dacron = polyester (PET)
Carl says:
Harbor Freight.
DeVos says:
That’s a good choice for life-not just buggy.
H2Oh says:
I’m confused.
Since The Rez is a freshamn dorm, how is this going to work? Are they going to take the buggy with them next year to where ever they will live? Or will the buggy stay with the Rez, and these guys will leave it in the hands of totally new freshmen. Or will they just continue working on it making it some strange type of org – I mean, its not an open student group like SDC and CIA since its for a specific dorm, and its not a closed greek because …. well its not greek.
What if some freshman wants to do buggy, but Housing places him/her in Mudge? Will that kid be forced to join SDC/CIA/Fringe or a fraternity? I’m totally confused with the concept of a [freshman] dorm buggy team.
Sam Swift says:
They could answer this better than I, but my understanding is that they are basically starting a new independent organization. Currently the bond that brought them together is living in the same dorm. That dorm may continue to be central to their identity as an organization, but it could also evolve and isn’t necessarily a long term defining feature. I think that’s behind the change from “Rez Buggy” to “Apex Buggy”
lemuroid says:
I recommend you skip the high-tech carbon fiber and vacuum bag approach and build something simple, possibly based on an aluminum truss frame. Expect it to weigh more than a leading buggy. Weight is not you enemy in year one.
Making it to the line on raceday 2012 will depend on your ability to bring something to the course early enough in the season so that you can learn what is wrong with it and fix it. That task has naught to do with the weight or size of your first buggy. Figure out the basics in something easy to work with and then Make buggy #2,( the 2013 model) the one where you start to think about weight and size.
Expect your first design to have many unplanned issues. Expect to have to move things around to make it work and to have too edit/rebuild at least two of the major systems (brakes, steering, pushbar, pushbar mount, axle mounts, wheel locations, windshield, wheels… ). Making these sorts of edits in carbon-sandwich construction, while trying to stay on a weight budget takes considerable time and effort. Taking “low weight” off your list of goals for buggy #1 will make this an easier task. Thus, an an aluminum frame based buggy that allows for a host of mounting points and allows things to be bolted on or welded on, may be a better starting point.
Shafeeq says:
I wholeheartedly agree that a buggy that can make it around the course is more important than a buggy that is light.
Second the slow epoxy & low temp (but not so low that the epoxy becomes too viscous) for layup. Be prepared for the real thing to go faster than the model (more fabric to fiddle with, more people and epoxy to push up the temp). That one’s bit me in the ass.
I’m not sure I’d recommend the Al truss approach, though. Although the materials and welding still aren’t cheap, a dedicated group of students likely could talk suppliers into donating some of that. Following the time-honored tradition of cribbing off of someone else’s buggy is tricky, since there aren’t any on the course worth copying, though maybe some alumni could let you poke around an old buggy or two to get some ideas. The biggest issue is that, as a new team, the thing you are likely to do at some point is crash. With a composite buggy, everything you need to fix it is in house, but with a frame, that’s going to involve finding a welding shop that can take you on short notice (unless you have the equipment & a skilled freshman). Bolted/riveted frames are possible but they have their own issues. Steel is cheaper & easier to work with, while, in theory, not any heavier if properly designed, but I can’t think of the last steel buggy.
Unplanned issues are a killer. Try to get things right the first time, but always have “if this turns out to be wrong, how is it likely to go wrong, and how am I going to fix it?” in the back of your mind, so you don’t paint yourself into a situation where the only fix is “build another buggy”. Everything that doesn’t go as expected is going to cost you time, money, reliability, weight, or any combination of the above. Weight is the only one that isn’t in short supply.
Sam Swift says:
I agree with Shafeeq’s opinion that a frame design is not best for a new team. I see Mark’s point about bolting things onto a frame and changing your mind being easier with a frame, but I don’t think the whole package is necessarily easier or more reliable. I would choose composite construction for buggy even if weight wasn’t a concern. This is definitely due to familiarity, but building experience within a technique is part of this decision. Building a frame first comes with the disadvantage of putting you relatively close to square 1 for your second build assuming you plan to go monocoque eventually.
lemuroid says:
My point was intended to be more about making the first buggy easy to build, easy to trouble shoot, and affordable to build(to allow more funds for fixing stuff). If a monocoque is the design, then consider making subsitutions of fiberglass for the carbon, polyester for the epoxy, and lower tech foam core vs nomex. This will lead to a reasonable buggy that would cost considerably less and might get you started sooner, providing more time to tweak.
An aluminum truss frame need not be a dead end btw. The aluminum truss based Jama,used a female mold for the body that was the basis for a string of successful monocoue buggys,
lemuroid says:
Elmo, I got your message, cannot reply due to login issue, Agree and thanks.
Connor Hayes says:
Hey All,
Thank you for your help and emails and suggestions! We have a design fairly set in stone right now and we are going to go monocoque. Now for an update! Tonight we received the official word from SDC that they would be funding us 500 dollars towards our build. Later today we have a meeting with Student Senate about more funding. Hopefully after tomorrow we will be sitting around 2100 dollars raised which will give us enough to build the monocoque. On top of that, we have been offered the chance to resurrect an old classic, Camo, to race in the spring in case our build does not get completed for the spring. So we are close to locking in our spot on raceday this year. We still need to raise more money to finish our own build as the final cost is going to come in around the 3500 range, and we are hoping to run some more fundraisers come spring. We really want to thank all of you for your help so far, and we honestly wouldn’t be able to make this happen without the great tips you guys have given us so far! You have been all so selflessly generous, we really don’t know what we would do without you. Thanks A million
-Love the guys and gals from Apex
Paul D says:
Camo has three wheels again? But seriously is no one willing to lend an acceptable buggy out for a semester? I would hate to see another new org have the same issues that DTD had with quicksilver.
Carl says:
Well, obviously, teams need to be able to donate their old buggies to the BAA (for historical preservation) and the BAA should be able to rent out old buggies to startup orgs. Though, for liability reasons, it might the most sense for the BAA to simply be caretakers and not owners (100 year lease for $1 sort of thing).
DeVos says:
Camo’s still around? Last I heard there were rumors of a dumpster burial.
Zatchmo says:
The battle between AEPi’s attempts to destroy nice things and the ex-AEPi’s attempts to save them rages onwards, but thankfully we managed to come out ahead with Camo. She lives, and is surprisingly in very salvageable condition.
PS – Anyone who has some old derby wheels, get in touch, please :)
Connor Hayes says:
Well on the whole camo thing, it’s two-fold. One it’s a fun idea, two it’s Cheap. It is by far the cheapest offer we have gotten for a buggy to use for the semester..
DeVos says:
I can appreciate the interest in the idea but remember to account for the costs to fix Camo up and the possibility (probability?) of a 3+ minute raceday time.
Paul D says:
It’s too bad we have so few rollable retired buggies. We are probably one of the few orgs that isn’t so concerned with secrecy to do so.
Shafeeq says:
My memory is that all the recent ones went straight from the raceday truck to alumni basements, so they should be as rollable as they ever were, except for spindles to fit currently popular wheels. Conquest would probably make a decent buggy for a startup team. It was great for the years we were clueless, because it just kept working despite our best attempts to screw it up. Whatever did Kappa/ZBT end up doing with Spectre/Ursula? I recall that BAA dug up a spare axle and other parts for them before last year, but they ended up with a Pioneers buggy?
Barsham says:
Sure, there are costs to fixing up Camo (like welding on a 3rd wheel), but I imagine it’s far cheaper than building a new buggy (which I would hope would be going on concurrently), much more likely to be ready for Spring Rolls, and probably doesn’t cost much more to fix than other old buggies (Quiksilver, etc.) that have been used by new orgs in recent years.
As for the time, with an A Team pushing, it will break 3 minutes. In fact, if Apex puts some actual work into getting it rolling at its capabilities again, it will roll somewhere around a 2:40 (or faster, if you’ve got better than 5 unathletic Jews pushing – It did a 2:39 in 1995, and a 2:41 in 2006).
I would expect that Camo would just be a backup plan, in case a new buggy isn’t ready to roll in the Spring. But I personally think it’s a great buggy to get your feet wet with, and I would think (hope?) that there are a couple of people who are in Pittsburgh (and maybe a couple outside of Pittsburgh, like myself) who would be able to offer specific support for Camo, unlike other buggies that might be available.
Paul D says:
Well as long as no one tries to weld aluminum to steel again it might work. As awesome as it would be to have Camo back on the field I still think rolling a buggy that needs that much work is a bad introduction to buggy. I mean its no small miracle that there are three derby wheels in existence, never mind all on one buggy. Whatever happened to the buggy ZBT bought from Sig Ep? Maybe Aiton would be willing to lend out conquest.
Connor Hayes says:
Hey guys,
So we got a bit of bad news tonight, Student senate has pushed their decision on funding us back, which puts a real chink in our plans to build our own buggy for this year. That being said, we are going to be out there and rolling on raceday. We are now looking for a buggy to rent or purchase for cheap (thinking $500 dollars but preferably less) so that we can still begin a build when more funds do come in. Right now, we are going around and looking at buggies to run for this year and we are open to all options. If you have offers please let us know. Now that we have more time to make our first build though i fully expect this thing to be a solid, solid buggy. Thanks all!
Connor Hayes says:
If anybody has a buggy to offer us please contact me at cmhayesny@gmail.com or send me a text or phone call at 631 404 9966
Connor Hayes says:
Good news today! Student senate reversed their course of action and has decided to fund us!!!!
Jerry says:
Congrats! Great to see things continue to come together for you guys. Is there any news on the buggy front?
Connor Hayes says:
Nope havent gotten any new offers yet. I sent out a few emails but have yet to hear back from anyone. Hopeful to get an early christmas present (aka a good deal for a buggy that is ready to roll well!)