Between 265 & 485 SQ/FT The 12-Gauge Garage

[Jack Olsen]

Yes. Twice. And it hasn't gone as well as I would like. The problem is getting the wing to return when the car is going more than 100 mph. I've moved the pivot point back twice now, and I think (hope) the second position is going to solve the problem. But I haven't gone out to test it the third time, yet.

 

[RonB001]

When I saw this, my first thought was: Oh, no, Jack's not selling his Porsche, is he?
On closer examination, it is blue instead of black, and SF instead of LA.

http://bringatrailer.com/2014/07/20/bat-exclusive-1974-porsche-911-streettrack-hot-rod/?utm_source=rss&utm_medium=rss&utm_campaign=bat-exclusive-1974-porsche-911-streettrack-hot-rod

I don't know enough about Porsche's to be able to pick out the similarities or differences.

Regards,
RonB

 

[Jack Olsen]

That's a nice 911 and -- especially considering the engine -- probably a decent deal.

No plans to sell my own.

 

[Squankum]

A commenter named BIlly bob at BAT asked:

"Is this owner the guy who has the garage fitted with the pea green cabinets and the car lift in his garage?"

Others have helped him out with that.

 

[Jack Olsen]

Thanks for noticing that. I'll probably jump in, now. The street/track early 911 is a pretty small niche in the car guy world. But I guess my car is known in that niche.

* * *

Messy garage today -- after all the work on the wing and building the bed and painting some other furniture for my daughter's room.

And... 45 minutes to square one. Except the wing. It's still on the car until I do the next test.

I'll never get tired of how easy this place is to clean up.

 

[Squankum]

If the motor(s) strength is a problem, have you considered a motor turning a gear that turns a larger gear 90 degrees, and that moves the rod up?

Oh, and while my garage is organized in the most important ways (but not all, yet), it sure is a lot more productive when you do start working, eh? Everything is where it should be, and you have at it.

EDIT: Of course, when I say 90, I mean 180.

 

[Jack Olsen]

It's kind of crazy. That Miata with the air-brake wing has its wing moving a huge range without any issue. Mine goes to the low-drag position without any issue. But going back to high-downforce is where it gets stuck. Once I slow down, it finishes its cycle, but that kind of performance is not going to get this project the green light to go out with me on the track.

I've been moving the pivot point back in order to create a kind of counterweight effect for bringing the nose down (and tail up). This picture shows the fourth position I've tried (all of the positions are numbered in the picture). The camera lens distorts things somewhat, but in real life it is still behind what I would assume would be the point of greatest downforce of the wing's profile.

Here it is in the low downforce position:

My theory had been that my pivot point was too far forward -- but I'm growing suspicious that it might be something else.

One idea I had is that it's possible the Miata motors might have damage to the gears right at the point where they need to raise the rear of the wing at speed -- the worm drive might be spinning. I can confirm that with a different camera monitoring position when the wing is in use, but I've opened up one of the units and the gears look fine.

Another idea I had was that it's possible that the power I'm sending to the motors might be 'weak.' (This is how you say things when you don't understand electricity.) It could be that the power source I'm using in the car is not up to the draw of the motors. So one option would be to tap into a beefier supply -- the main feed to the starter motor is nearby. But it could also be that the run from the power supply to the motors is too long, relative to the gauge of the wires.

I'm still thinking about it.

And I'm open to any suggestions. I've got video of what it looks like when the wing is not working correctly, but I don't know that seeing it would help. It stops (with the in-movement light remaining on) and then finishes the cycle once the load has been reduced.

 

[Outlawmws]

Jack, I'd agree with the power supply issue for the motors. Motors draw a lot of juice:

I'm guessing you have a wire going from the battery to the cockpit switch and back again?

I'd get a larger buss wire to a relay, Then again from the relay to the motors (possibly a pair of relays...). Your switched wire should be small as all it has to do is run the relay.

You can save one run of wire from the cockpit to the relays, by feeding the relay with hot power and then from the off side of the activation coil pole to the cockpit switch and have that switch ground the circuit

 

[Outlawmws]

Jack I also noticed another factor:

The angle on the wing actuating rod to the pivot point from up to down is very extreme:

The actuating rod connection on the wing is up way too high compared to the pivot point. You lose a lot of leverage when you get up high, just when you need to the most. You need to shorten the actuating rod maybe around 3-4 inches so it is working from a negative angle to a positive angle and as nearly at 90 degrees to the pivot point in the 1/2 position as possible.

Look at the angle between the pivot point and the rod in the up position. The angle is VERY acute and getting sharper as it goes up.

 

[Crown]

Couldn't hurt to try this setup, if it doesn't work you at least saved some weight by drilling an additional hole: move the pivot point towards the red dot creating an arm twice as long. It will also help if you'd push it at a 90 degree angle instead of the 35 degree angle right now: most of the force from the motor is eliminated because it wants to "stretch" the aluminium plate instead of pushing it up right now.

 

[Nolift911]

Just a couple of things - again that is MUCH force you are trying to counteract.

Some of these motors have a resistance point where they just give up to protect themselves...my guess is snow/ice frozen on the hood of a Miata would force them into preservation mode, if they could not lift the buckets.

Not sure of the mechanism or what "point" that is on the force scale or if it is adjustable/removable.

Maybe "twin" spoiler motors from a 964, 993?

Only other thing is gear reduction, as mentioned earlier.

All just SWAGS on my part - cool project

 

[sands35]

Not sure if you have a fix, but I used multi stranded CB handset coiled wire for steering wheel mounted switches for my DAQ system. Something like $10 for 2 feet. Nice and thick with more than enough flex for a removable steering wheel.

Great idea on the wing servo!

Wondering if a slightly bigger servo unit would work better? BMW or MB junkyard pull?

I can't see the details around the wing pivot, but if it is single sheer, they might be binding up when loaded. You may need to do a double sheer pivot with pressed in bronze or HPDE bushings and a bigger bearing surface. I know that BMWs have HPDE bushings for brake pedals. High load, low cycle rate application. Not much different than what you are doing in terms of applied loads on the bearing.

Throw a few hundred pounds of sand bags on the wing and see if the pivot deflects at all. This will help with diagnosing the pivot issue in the garage.

No affliation:
http://store.bimmerworld.com/rogue-engineering-delrin-brake-arm-bushings-p1914.aspx

I think somebody suggested a similar idea - but moving the push rod to the front of the wing rather than the rear of the wing will get the rod acting closer to 90* angle - more efficient that way. You can't "hide" the rod behind the wing uprights that way though.

 

[OopsClunkThud]

As you move the pivot point back (leaving the actuating rod in the same place) you are shortening the lever arm requiring more force to apply the same torque to the wing.

At the motor end, the motor produces a given torque and the longer the lever arm, the lower the force. At the full up and full down the lever arm goes to zero and the forces are plenty high. I suspect it's getting stuck at the mid point when the lever arm is at its maximum length. May be as simple as adding a spring at the motor end. The force of the spring would be max when the force of the motor is at its min.

 

[Sonny2010]

Amazing setup!

 

[Sonny2010]

Not sure if you have a fix, but I used multi stranded CB handset coiled wire for steering wheel mounted switches for my DAQ system. Something like $10 for 2 feet. Nice and thick with more than enough flex for a removable steering wheel.

Great idea on the wing servo!

Wondering if a slightly bigger servo unit would work better? BMW or MB junkyard pull?

I can't see the details around the wing pivot, but if it is single sheer, they might be binding up when loaded. You may need to do a double sheer pivot with pressed in bronze or HPDE bushings and a bigger bearing surface. I know that BMWs have HPDE bushings for brake pedals. High load, low cycle rate application. Not much different than what you are doing in terms of applied loads on the bearing.

Throw a few hundred pounds of sand bags on the wing and see if the pivot deflects at all. This will help with diagnosing the pivot issue in the garage.

No affliation:
http://store.bimmerworld.com/rogue-engineering-delrin-brake-arm-bushings-p1914.aspx

I think somebody suggested a similar idea - but moving the push rod to the front of the wing rather than the rear of the wing will get the rod acting closer to 90* angle - more efficient that way. You can't "hide" the rod behind the wing uprights that way though.

Yes! Agree 100%

 

[Alexbn921]

The wing and push-rod assembly might be flexing and preventing one motor from completing its revolution. Then the motors would fight each other and not lower the wing.
There should be an 5th indicator wire coming out of the motor housing that you could use to indicate witch motor is having trouble and when.

 

[Outlawmws]

Here is what I'm talking about mechanically; the red arrows indicate the angles you are seeing now, you have no real leverage as you get close to the up position:

The blue indicates where the arm and rod should be for max leverage:

Ignore the arrowheads, crummy annotation tools at work....)

 

[Outlawmws]

You can also move the pivot point on the support up an inch or so to lessen the angle, but it won't be enough by itself.

 

[Craptain]

I think Outlaw is on the right line. I tried to draw the pictures myself but had issues with the software. (Well, the user of software). Be careful of the length of the lever arm. The longer you make the lever arm the lower relative movement will be at the wing, but it will also give a stronger the force to drive the wing.

 

[Outlawmws]

You can also use the ratio of the effective wing arm to the motor's stroke to select the total degrees the wing moves.

 

[Jack Olsen]

Thanks, guys. I got sidetracked by some (more) stuff for my daughter's room. But pretty soon I want to get back to this. I have some ideas I want to run by the brain trust here.

 

[Zeke]

You're either going to do a wheelie or rip the decklid off the car

 

[Motorhead Extraordinaire]

The problem with your wing might lie in the aeronautical phenomenon referred to as Hinge Moments which will cause a wing (or aileron) to effectively lock into a given position. I was involved in a study back in 1971 where a surface to air missile the Army was testing went into divergent oscillations due to hinge moments. After almost a year of detailed studies and simulations, the fix was an airflow change, not an actuator change.

When an aileron gets hung up in a position due to hinge moments it become nearly impossible to snap it out of its aerodynamic lock.

You might want to consider looking at the airflow around the shape of the wing and the position of the hinge point with respect to the wing. Our answer to the missile hinge moments was to create a wing opening around the hinge for air to pass through without locking up the hinge point.

Not sure what will work in your case but it may not be a bigger actuator.

Joe

 

[Jack Olsen]

Here is the bedroom project.

My sister made my 2-year-old daughter a great quilt, so we used that as a launching point to finish up Molly's bedroom. The furniture belonged to my wife's grandmother, and has sentimental value. We plan to refinish it when Molly is old enough to be trusted to not destroy it with markers and Hello Kitty stickers. So the paint is both a preservative and a way to get this all put together in a hurry.

First, Max and I picked up some lumber to make a platform for Molly's mattress.

I'd never built a bed platform. It's for a memory-foam type mattress. Here's what I came up with on the cheap.

http://scontent-a-lax.**.fbcdn.net/hphotos-xpa1/t1.0-9/10500584_10204166828195260_8006216716090495211_n.jpg

http://scontent-b-lax.**.fbcdn.net/hphotos-xap1/t1.0-9/10471195_10204166827515243_1130309551893603166_n.jpg

Primed and being tested:

http://scontent-a-lax.**.fbcdn.net/hphotos-xpa1/t1.0-9/10403610_10204166827875252_5170787387301436523_n.jpg

Then the other furniture:

There was a great mural in the room that we'd had for 11 years. It was starting to come off, though. We'd used it for both kids when the room was a nursery. But now it was time to say goodbye to it.

Max helped with the scraping.

And the priming:

What Molly wanted was one pink wall. And that's what she got.

Here's the whole room, quilt and all.

Now, back to some work stuff -- and then that wing.

 

[horizontallyopposed]

Jack,

You have this dad's seal of approval. The looks on your kids' faces make it all worthwhile!

Cheers,
Keith
1969 912R

 

[1Garageman]

You did a great job making it, and also an even great job getting your kids involved in the project! That is awesome making things with your kids and having fun! Great Job!

 

[79 Euro]

Jack,

Max and Molly look like great kids. They grow up so fast. Mine are now 25 and 18.
Love the garage!

Andy

 

[Jack Olsen]

Thanks! Having started late and with two very young kids, still, I can see that -- while every hour is very long, these days -- every year goes by very quickly. If that makes sense.

Onto the wing.

The reason I've been moving the pivot point back is to try to find a kind of 'balancing point' for the wing, so that the force my motors expend isn't to move the 400# the wing might be pushing, but -- wheelbarrow-like -- to rotate the thing with the downforce still being pushed down through the uprights. Based on the high-low pressure data (and the advice of the people in this thread), I'm assuming that balancing point is about 1/4 to 1/3 of the way back fromt he leading edge of the wing.

Here's my illustration for the way I'm understanding it (I hope):

Now, the next thing I'm planning on doing is to get my reat attachment point pushed back as far as I can manage, to increase some of the leverage that moving my fulcrum back has removed. In other words, I've made that arm shorter and increased the total change in angle of the wing. What I'll do next is measure a reasonable amount of total movement I'd like, and then extend the connecting point back as much as I can while still getting the right total amount of movement. I'll also shorten the arm, per MSOutlaw's (and others') suggestion:

This will mean making four new aluminum pieces that connect the wing to the uprights. And I don't think I'm going to get the time to do that until next week. But that's my plan. If anyone sees where I'm making a mistake, please sound in here. But I think that makes the most sense.

 

[Jack Olsen]

Here is the new basic shape I'm going to try. The 7" distance between the pivot and the connecting point will mean a 14° net change in angle.

 

[sean Buick 76]

Cool progress with all your projects.... Just so you know, you have inspired many of us to make the best with the space we have!

 

[frijolee]

Hi Jack,

Just wanted to say thanks for the time and attention to detail that went into documenting your garage build. I've just spent most of an off-Friday reading through the whole thing (yep, beginning to end). I think it took longer to read this one thread than to skim every other <600 sq/ft garage on the gallery board. I knew of your garage from Hot Rod, I think, but reading through the full build was really helpful in getting ideas behind some of the "why" you ended up with things you did.

My wife and I just bought our first home in Tustin CA (Orange County) so I've been doing a great deal of reading, planning setup, and trying to get it as close to right up front as I can. The garage is a 20x21 (sounds familiar) and is planned to be workshop plus one car garage for a go fast daily driver that seems some track days (sounds more familiar).

My car:

There's a 429 ci LS2 under the hood so maybe I'll see you out on track sometime and get to introduce myself properly.

I should tell you that I found myself jotting questions as I went along and one by one, you've already answered the vast majority of them. For instance: I wanted to ask your opinion the discussion on open shelving for quick access vs. cabinet doors (Answer: doors make a less cluttered look in post 2449). I'm guessing it helps with clean up too.

What temp. lighting do you like for CFLs? (Answer: 2700k but that was earlier in the thread and didn't note where you posted that).

What do you think is an ideal ratio of storage to work benches (Answer, as much working surface as possible post #3391, with a lot of other great design concept info). You might consider putting some of that post on the dedicated website.

Where do your big tools live? (Answer: in the shed). BTW, if you showed off a picture of your air compressor setup I missed it but I assume it's in the shed.

Just a couple things I couldn't find:

1) Do you have contact info for sources of liquidators on Stronghold Cabinets? You alluded to a company on ebay early in your thread, but the only link I found doesn't seem to have any now (might just be a dry spell). http://www.ebay.com/sch/reliabletoo...&_odkw=&_osacat=0&_trksid=p3911.c0.m270.l1313. Alternatively you also mentioned at one point being in a warehouse with about 200 of them. Can you share where that is?

2) What are other brands of stout old school cabinets and the like which you approve of. My list of names I jotted down throughout the thread included: Stronghold, Lyon
Lista, Equipto, Vidmar, Rousseau, and Nu-Era, but I haven't researched any of them yet. Any particular commentary on who you like for what?

3) How do you like the spacing of car vs. benches? It looks tight on the passenger side, but your lift negates that for the most part. Before you had a lift did you ever even try to open the passenger door?

4) What do you do for general storage? Camping gear, maternity clothes, snow gear/sleds, sports equipment, etc.

Apologies if any of this has been addressed before, but I was trying to move through the thread relatively quickly and there's obviously a great deal of info here. I enjoyed the tangents on deck building and race car aero. I think I have a Harbor Freight tube roller in my future.

Regards,
-Joel Payne

 

[metalhead140]

Cool progress with all your projects.... Just so you know, you have inspired many of us to make the best with the space we have!

Seconded!

 

[Kabman]

Hi Jack,

This suggestion may be a little late in the day. After wading through nearly 200 pages and getting sidetracked hunting for steel cabinets on Ebay I've only just got to this page.

With the pivot point where it is, it looks like the centre of pressure will move backwards when the trailing edge of the wing is lowered. So the vertical (downforce) component of the force will give an increased anticlockwise moment about the pivot. (We could easily be talking about a decreased clockwise moment depending on where that centre of pressure really is or how much the downforce decreases by but it adds up to the same thing and every little will help).

I don't know for certain (maybe DocRocket can step in here) but I would expect the best pivot point for minimum change in moment would be through the wing itself. That would be tricky to engineer but get the pivot as close to the wing as possible. It might require hacking the uprights to get enough clearance though.

 

[Jack Olsen]

Thanks.

Kabman, that's part of the plan as well: to move the pivot point as close to the wing as I can manage. I'm going to check again to see if I have enough scrap stock to make new uprights or not. If I can do that, I can get it much closer. But in any case, I can go about an inch and a half closer with the only penalty being an overall lower height for the wing itself.

 

[HandySandy]

 

[Jack Olsen]

Here's the new piece. I have 7" between the pivot and the connection point (for 14° of travel). I've raised the pivot point as much as I can without making new uprights. If the basic idea works, I'll make new uprights and improve it even more.

And here it is in action:

More testing next week.

 

[DocRocket]

Basically, I think you will want to get your pivot point onto the chord line (or close to it) at the 1/4 chord point. That should be the point at which the aerodynamic forces on the wing are acting, and about which the aerodynamic moment is fixed. In your case, that might actually be above the wing as it sits.

If you have it below the wing, the lever arm is the distance from the pivot point to the chord line (at the1/4 chord point--this may be greater than the distance the pivot point is below the wing--probably is) * the sine of the angle displacement from the design, zero angle, position. In this case, the lever arm *sine product could easily be around 0.1 ft, so you would get a 40 ft*lb or so moment on the pivot point that your actuator needs to overcome. If you can find a way to pivot the wing about the real aerodynamic center, you may find that it moves easier, but that may be hard to accomplish without moving structure above the wing.

 

[Jack Olsen]

That could be the nudge I need to go to the swan's neck style uprights.

 

[smschriefer]

Wouldn't it be easier to use a flap to change the airfoil in profile instead of changing the angle of incidence of the entire wing? I would think the reduced surface area would be easier to move.

I agree that you'd preferably put the pivot within the cord of the wing, but that isn't something I can see being done easily. Maybe just a small flap used in conjunction with your pivot point would be enough to disrupt the airflow to aid the motors with their task.

 

[OopsClunkThud]

May be possible to create a four bar link that puts the "pivot point" (instant center) above the wing with all the linkage below.