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Matthew Kennedy
Matthew Kennedy GRM+ Memberand Reader
10/27/22 5:21 p.m.

In reply to bumpsteer :

Don't make me charge a tesla using a drill, then plaid my way in to the record books.

barefootcyborg5000
barefootcyborg5000 PowerDork
10/27/22 5:23 p.m.

In reply to Matthew Kennedy :

You are right. I was assuming torque was fairly flat across the rpm range. It isn't. I corrected my math in subsequent posts. 

Matthew Kennedy
Matthew Kennedy GRM+ Memberand HalfDork
10/27/22 5:29 p.m.

A DC brushed motor dyno chart looks something like this:
I need more torque? - RCCrawler

Peak power usually near half of the free speed, and 1/3 to 1/2 of stall torque.

 

That means these drills are something like 75 watts assuming a stock battery. I bet you could double or triple that without too much issue.

 

Edit: It's actually more like 0.8hp ~600 watts, I missed a 2pi in the math

ProDarwin
ProDarwin MegaDork
10/27/22 6:48 p.m.

Some notes:

1)  I meant to word the original rules so you couldn't store any potential energy via winding/compressing/whatever.  Not sure exactly what the wording would be.

2)  I've never been to challenge, but I want to go.  If this happens I am 99.999% in.  Someone who has been/GRM staff should set the "track" config, meaning acceleration zone, top speed measurement zone, etc.  I imagine a drag strip 1/8th mile might be a good option?

3)  My googlings earlier showed a few people measuring cordless drills in the 400-600watt range, so I figure power is around there.  Thats enough to get well over 20mph (maybe 30mph?)  pedaling a bike.  I imagine if we are squeezing out more juice and making more efficient contraptions/aero, someone might see 40-50mph.  Maybe that is too fast?  I dunno.  Could be reason to force the smaller drill.

4)  I don't think there is a minimum target of tires/etc.  Something bicycle based is probably going to be the starting point for most people, but I think aero could really come into play.  Maybe specifying more wheels would keep the speeds lower though and add stability?  It would certainly increase the complexity of an entry though from something you could possibly shove in the trunk of a car, to a go-kart sized thing.

5)  I'm open to spec battery pack too, but I figure the first thing people would want to do is feed more juice, and I think the danger of melting a motor or battery pack is part of the fun :).  Maybe a max # of cells?  Or maybe you must keep cells from one pack, but mods for better conduction & cooling are allowed?  

barefootcyborg5000
barefootcyborg5000 PowerDork
10/27/22 7:11 p.m.

I think if we are to have separate classes, it should be 2 or 4 wheels. Both using the same drill. If single class, I'm in favor of 4. 
If the drag strip is too sticky or unavailable for whatever reason, I could see the auto-x area easily repurposed for a 250y land speed run. 
Not to be unpopular, but maybe brakes on both axles should be mandatory? Or maybe brakes on at least two wheels?

 

fusion66
fusion66 Reader
10/27/22 7:13 p.m.

I am very interested in this idea. I have not yet been to the challenge but the addition of $2000+ cars, a FIRM track day after the event (if it happens again), and a chance to play with cordless drills for a speed contest should be enough to push me over the edge and make the trip down. 

My .02 cents which is likely way overpriced. 

Either have a rule allowing the two drills listed at the start and only stock batteries or narrow it down to one drill and have a stock battery and modified battery class.

My logic is that two drills plus a choice of stock or modified batteries leads to four potential classes which might be too many for a fledgling idea. Limiting it to two class options (or even one potentially) might get the best head to head competition in year one and then grow from there if it makes sense. 

I lean towards a time between traps (convert distance covered over time to speed over that distance) with a very generous acceleration zone such that rider mass will have less impact on the final result. If the drill is still in the acceleration phase and not top speed phase through the traps it will certainly penalize more "robust" riders. Alternatively I will be forced to pay my 8 year old nephew to pilot it smiley

Open configuration for wheels with a minimum of (2) would be cool to see what people come up with. My initial thought was longboard if the area was very smooth but to increase the likelihood of not injuring myself a push scooter with the large wheels (8"-10") would likely be safer. Some type of bicycle wheeled creation would likely be fastest but I am thinking about options that fit in a Miata trunk.

Curious to see where this idea goes. 

I can't help but wonder how long the 20V drill motor would last. Test run at 40V, then hit the 80V nitrous button  

 

bumpsteer
bumpsteer New Reader
10/27/22 8:18 p.m.
fusion66 said:

I can't help but wonder how long the 20V drill motor would last. Test run at 40V, then hit the 80V nitrous button  

 

barefootcyborg5000
barefootcyborg5000 PowerDork
10/27/22 9:04 p.m.

^^^ 

Is it even really racing if nobody lets the smoke out?

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
10/27/22 9:23 p.m.

In reply to bumpsteer :

that's on the territory of "I built a challenge car powered by HammerStore batteries for challenge budget"

Matthew Kennedy
Matthew Kennedy GRM+ Memberand HalfDork
10/28/22 12:34 a.m.
ProDarwin said:

1)  I meant to word the original rules so you couldn't store any potential energy via winding/compressing/whatever.  Not sure exactly what the wording would be.

A simple wording here could be "no energy storage outside of the battery powering the drill". If you want to allow flywheels, add the word "potential" before "energy".

 

What is the proposed timing method? 1 mile run-up then 10' timing gate? 100 foot drag race? 50' run-up then 50' timing gate?

If you want to measure top speed, it needs to be long run-up, then short gate. If you want to measure power output, then short or no run-up.

ProDarwin
ProDarwin MegaDork
10/28/22 6:58 p.m.
Matthew Kennedy said:

 

What is the proposed timing method? 1 mile run-up then 10' timing gate? 100 foot drag race? 50' run-up then 50' timing gate?

If you want to measure top speed, it needs to be long run-up, then short gate. If you want to measure power output, then short or no run-up.

I'm hoping other people have some recommendations.  I haven't been to the challenge, but I imagine you'd want to run it at the autox lot or drag strip?  Put the timing gates only far enough apart to ensure good accuracy.  

Long run up would be ideal, but really I would let the space available drive that.

 

rich911s
rich911s New Reader
10/29/22 4:44 p.m.

I'm in.  Def need some rules. 

1) are we going to have to start on drill power only or will there be a push off of some kind allowed? Push off by another competitor, etc. or no push off.   

2) I'm all for a spec drill and battery.

3) Do you have to drive it yourself, or can you get your 100lb kid to do it for you (saves 110lbs!)

Black Friday will have tons of deals on drills.  in fact there are many on sale right now with all the early BF sales.  Amazon and ebay have plenty of cheap options too.  I suggest a 4.0AH battery minimum, but that's just my pref.  

ProDarwin
ProDarwin MegaDork
10/31/22 10:32 p.m.
rich911s said:

I'm in.  Def need some rules. 

1) are we going to have to start on drill power only or will there be a push off of some kind allowed? Push off by another competitor, etc. or no push off.   

Pushoff makes sense to me. 

No pushoff would definitely increase the challenge.  Gearing for top end might make something that would take forever to get moving/wouldn't balance.  Then you'd need to compromise or even run a 2 gear setup.

fusion66
fusion66 Reader
11/1/22 7:20 a.m.
ProDarwin said:
rich911s said:

I'm in.  Def need some rules. 

1) are we going to have to start on drill power only or will there be a push off of some kind allowed? Push off by another competitor, etc. or no push off.   

Pushoff makes sense to me. 

No pushoff would definitely increase the challenge.  Gearing for top end might make something that would take forever to get moving/wouldn't balance.  Then you'd need to compromise or even run a 2 gear setup.

But the Big block version already has a 2 speed gearbox...I really want to see someone take off quickly from a standing start  and then shift on the fly to a top speed record smiley .

A little push to get things moving seems like it would be a good option for balance reasons.

sleepyhead the buffalo
sleepyhead the buffalo GRM+ Memberand PowerDork
11/1/22 9:41 a.m.

I think a "5ft foot push" zone delineated with cones is a reasonable allowance

fusion66
fusion66 Reader
11/1/22 10:45 a.m.

I don't think you can do polls within this forum structure...but would be curious ot see where the most interest lies to avoid building into a class of 1.

1. Warrior 18V stock battery

2. Warrior 18V modified battery

3. Bauer 20V stock battery

4. Bauer 20V modified battery

If you are thinking about doing this, please consider posting your most likely to least likely class to run in below.

Me - 3,4,2,1

ProDarwin
ProDarwin MegaDork
11/1/22 10:58 a.m.

4321

But I'd rather see all 1 class that a bunch of different options. I think even my suggestion of 2 classes was a bit optimistic.

nocones
nocones GRM+ Memberand PowerDork
11/1/22 10:58 a.m.

I would mimic the GRM class structure.  

GTN = GDW

GTW = GDB

GTU = GDU

GDB is Great Drill Warrior for 18V

GDW is Great Dill Bauer for 20V

GDU is Great Drill Unlimited, only rule is must use Unmodified Warrior or Bauer Motor and Gear box, must drive through standard Drill Chuck.  Battery, speed control, etc. Unlimited.  

 

hobiercr
hobiercr GRM+ Memberand UltraDork
11/1/22 11:11 a.m.

My $0.02 is for the first year we should just have one class to encourage participation. My vote would be 3 (Stock 20v).

fusion66
fusion66 Reader
11/1/22 11:20 a.m.
hobiercr said:

My $0.02 is for the first year we should just have one class to encourage participation. My vote would be 3 (Stock 20v).

I made a similar comment earlier and agree. This might help us align on the preferred class. 

I am torn because I really want to let the magic smoke out of at least one drill but that could wait for year two smiley

ProDarwin
ProDarwin MegaDork
11/1/22 11:27 a.m.
fusion66 said:

I am torn because I really want to let the magic smoke out of at least one drill but that could wait for year two smiley

After your official run, swap for an exhibition run?

I also want to let the smoke out.  Unlimited class is the most appealing to me.  But I'll run whatever has the most support.  And since this would really be a side competition, the "sealed" classes would have lower costs.

barefootcyborg5000
barefootcyborg5000 PowerDork
11/2/22 12:46 a.m.

I'd vote single class. Either 20v unlimited or 20v spec battery. 10' push start, no assistance. 

rich911s
rich911s New Reader
11/2/22 11:59 a.m.

Liking all the creative ideas.  Right now I'm really liking Nocones GDU.  Run a spec drill, and let people go crazy with the batts and build.  Most likely everyone has at least 5 batteries of their preferred brand laying around that they could cobble together.  Since batteries are the most expensive part of the build, that would reduce the barrier to entry cost wise and hopefully increase participation.  Chassis unlimited  -  Unicycles encouraged. Lets get some rules started!

Spec Hammer Store Drill Challenge

This event is meant to be a fun exercise to show how incredibly childish, moronic, and dangerous very smart people can be when encouraged by their peers.

Rules:

1.  All participants in the SHSDC must use 1 spec drill for the challenge.  For 2023,  _____________ is the spec drill.  The use of more than 1 drill is not permitted. 

2.  The spec drill must remain unmodified and factory sealed.  NO modifications are to be made to the spec drill, including but not limited to: disassembly, polishing, cleaning, re-wiring, porting, etc.

3.  The transfer of energy from the drill to the vehicle must be delivered through the factory drill chuck, which in accordance with rule 2, shall remain unmodified.  From the chuck it can be routed through any and all ancillary mechanical device(s) to provide power to the vehicle.

4.  Any stand alone chemically derived battery is allowed.  Car batteries, drill batteries, double A's, Tesla batteries, etc. are all permissable.  By this criteria, solar panels, extension cords, and generators are examples of power sources that are NOT allowed.  Battery chemistry, voltage, and amp hours are unlimited. 

5.  Batteries MUST be mounted to the vehicle.

6.  The vehicle engineer and/or owner must drive the vehicle.  If made by a team, all team members are eligible to drive.  Lighter weight substitute drivers are not allowed.    

7.  The competition shall take place on the staging lanes fo the Gainesville Raceway.  The total course length is 360'.  

8.  Push off is optional.  If elected, Push Off is allowed in the first 10' of the course.  Push off can be by the driver or a single team member or volunteer. 

9.  No additional driver assistance is allowed after the 10' push off section.  All subsequent momentum shall be provided solely by the drill.

10.  Each vehicle is allowed 3 timed runs.  Winners are determined by shortest elapsed time from the start to finish line. 

Proposed course:

 

I also propose a $10 entry fee, with proceeds awarded to the top 3 finishers.  60/30/10 as the award split.  For example if 20 people enter there will be a $200 prize pool, $120 to the winner, $60 to the second place, and $20 for third. 

That should get things started, jump in and lets get these rules hammered out so we can get on with the building!

 

 

Shadeux
Shadeux GRM+ Memberand Dork
11/2/22 12:41 p.m.

In reply to rich911s :

(raises hand) 

Question about #3:  "From the chuck it can be routed through any and all ancillary mechanical device(s) to provide power to the vehicle." 

So, would this include, for instance, a 10 speed gear set from a bicycle?  'Cause I'm fat and I like the stock class idea.

rich911s
rich911s New Reader
11/2/22 1:10 p.m.

Not sure how many gears you can get through in 350' on drill power, but sounds like a great plan to me!

Something like so, but without the ice studs!

Incredible Studded & Drill Powered Bike - YouTube   

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