95 replies to this topic

[Duffy]

See, here's the deal:

I'm young enough (read: newly returned, and "It's never too late to have a happy childhood") to be pretty darn ignorant, and:
Experienced enough in divers engineering and crafts backgrounds to muck up any modesty I could muster to address the ignorance.
So, I'm basically screwed.
Can't learn from scratch, I'm 45 years too late; and can't start from a place of NOW, because part of me wants to know the why of everything that's going on. Which means--
Can't just build a Retro car.

Ohh, I've tried. Did all the homework I could, talked to a lot of knowledgeable & helpful Old Dudes, & have begun to get a sense of what a chassis is all about. Fine & good, but any time I tried building something per another's example I'd get bogged down--"why's he doing THIS here, I don't see how/why..." And my attempts so far either have been hampered by my not-seeing the intent in whatever example I'm looking at, or (in some cases) the intent has crept somewhat from its origins--a thing the proto builder might have overlooked, and for which I have no perspective at all!

So, it's time to learn. Ergo, the present build, for learning. Later, in the Vanity Shots, I'll give props to the guys who set the design direction for this.

FOR NOW, two things I know: (1) I want to learn what different elements of a chassis do, individually and in concert; and the way to do that is to build a chassis I can try things on--check an idea out, see what it does, swap & compare, run against itself (meaning, two or three of the same original roller); and (2) I need to have something that'll survive my driving and not break while I try it out. Up to now, I've had something break at every race I've run. My sense of stressing-out a structure, at least as I've copied others to date, is way lacking. So, I wanna build a bombproof chassis that I can quickly & conveniently swap in new elements on.

AND I"m writing it all out here, because someone in my present state of hobby might happen along and find something that resonates. The rest of you lot, I hope it entertains.

Okay then.

Sooo, I lit some candles, put Dr. John's "Danse Kalinda Ba Boom" on the box, and Waited For My Rider To Come.
And, from Out Of The Swamp--



THIS emerged: nosepiece .040" sheet with .050" reinforcer. Rick Geo immediately dubbed it the "Hoodoo"--in
response to my naming his a/w nose "Choirboy" last month. Fair enough, and I'll play with that. The guide tongue
in the nosepiece is cut narrow for better coining of the radiused step, and then--



--the reinforcer angle extends further out, like a hood. Here you see what the little tabs in the wheelwells were for,
I've bent 'em over to make heavy-duty plumber hinge "gudgeons" instead of trusting wee little soldered-on bits of
flimsy tubing. Bombproof, remember?



Besides which, as I experiment with "shaky" & "twisty" plumbers, I can root out these holes in any way I wanna
try. If something don't work, I just hammer 'em round again...

The only other fancy thing I did here was the shaker pintubes:



Now, Marty Stanley posted some cool stuff the other day, he just set a little bit of aluminum tube in a handy hole
and used it as a depth stop to solder grommets onto tubes--well, I made two bits of tube, used one to set a
filed-short grommet to length, then slipped the wire you see here around and soldered on another grommet
below. Presto, shaker pintube. I can bend the wire bracket to set whatever height--



--Which I get from my standardized Can-Am body template: just set it up in the jig, fit the pintubes to the holes,
tack in. Now all my bodies can be drilled to match all the chasses.

A quick return to its Element, in company with Don Undead--



--And a little buff, & we're ready to take Vanity Shots. Presenting HOODOO Ver. 2. Like my man Muddy,
I am Holding My Own...



In conversation with Matt Bruce and TonyP, I tried to get away from the full-pan (and "Painted With Lead")
tradition I was running, opening up somewhat and concentrating mass in three specific areas instead of
all the way across; should give me the same mass moment with less baggage in between. On a whim,
I figured I'd go Plumber and see where it led me.

Nosepiece .040" & all the rest .050"
Main rail .078"
Plumber & front axle-brace .062"
Full-floating bite bar .055" in .065" sq. tube



Here's the front end. Axle brace pulls extra duty as nosepiece stiffener. Here you can also see the slop limiters
on the plumber pintles, the little U-bit stopping the outer end of the wire to keep my 3.125" width constant and
adjustable inner slop bent-in.



Rear end will have ball bearings. In this first iteration, I'm spreading out the footprint for the bearing sleeve so I've braced
it pretty heavy. I may bring 'em inboard later, as some guys're talking me that way. This is RGeo's new Retro bracket,
.050" brass with proper corner radii and plenty stiff by itself, & the holes are accurate to Duffy-specs, no small deal.
Like 'em a lot.

This will hit the track next Thursday, with a Puppy Dog inside, and I'll have a chance to run it against Ver. 1 with its TSR D3. That one wanted a .50" square of Lead Paint at the front corners, and with that the car got glued to the track, rear swinging out most predictably. Big, big improvement, & I hope I'll see more with the presumed lessons I've built into this one. More later if it's significant.

[Alchemist]

Real nice Duffy! I like it!!!!!!!

Ernie

[Mopar Rob]

Did 15 year old Duffy cut that nose piece out with a coping saw or did older Duffy machine that out after work?

Anyway interesting piece.


I really like universal pin mount system. Not sure if you ever have posted that before?

[Duffy]

Did 15 year old Duffy cut that nose piece out with a coping saw or did older Duffy machine that out after work?

HAH!! 60-yr-old Duffy roughed it out on a bandsaw and filed the pertinent surfaces to size, as his Geeky Inner Duff complained loudly.
--Particularly about having a decent Datum-Dedicated jig to tweak measurements off of as I filed!!



May try to stay Forever Young, maybe, but hopefully not forever foolish.

I really like universal pin mount system. Not sure if you ever have posted that before?

Yah, some appeared in Marty Stanley's thread. Marty opened up a way to make this fussy drudgery easy, and I thank him.

Duf

[Pablo]

Sweet
I love the shakey shakey pin tube mounts, overbuilt and proud of it

Thanks for the pic of the bulldog clip holding the device that ensures the thingamabobs are flush on the sides;
that frees up one hand..... nice !

I think you are on the right track.. The HOODOO scares the crap out of me

[Duffy]

Oh, yah. When I was givin' it up to the guys who stagemommed me with this concept, I didn't mention Pablo, who unselfishly hammered on me nonstop for 72 hours to NOT OVERTHINK THE DAMMED THING. Thank you, Paul.

[Pablo]

Be sure and let me know if the front clearance turns out to be perfect after the wheels are installed.
No cheating by multiple Hudy trimmings; I want you to tell me they come right out of the bottle and clear a perfect .020

[Marty Stanley]

Duffy,

My friend, you are more than welcome! Hey, it was sitting right in front of me and all of a sudden I went from rounded shoulders to a flat forehead and just wanted to share the idea! As you are more then aware, sometimes the most obvious tends to stay very obscure!

Now, you made this statement, "May try to stay Forever Young, maybe, but hopefully not forever foolish." I'm not sure how you intend to perform the latter, but I hope we both continue to perform the former, forever!

I had tried those 'little springy thingys' awhile back and really didn't like them. Oh they worked adequately, but there were some issues during the mounting of the body I just did not care for. I have pretty much settled on a new way of doing that. Since you liked the other tip, here is a photo of my new moving body mounts.

Basically it is a piece of .032 wire inserted into a normal .014 walled piece of 1/16 brass tubing that is soldered to the main rails of the chassis. The body mount passes through a piece of 5/32 tubing that is soldered to the outer pan. That limits the movement. You simply make the bend in the .032 wire, solder the body mount to that and it's nice, light, cimple and easy to make. There is a piece of .015 wire going back to the bite bar to control the rate that the body mount moves.


Pablo,

You said, "I think you are on the right track.. The HOODOO scares the crap out of me "

Once it's been tested and Duffy finds out that it works as well as we both think it will, we can both say - simultaniously if applicable - "Duffy, You Do that VooDoo that makes Hoo Doo work so well!"

BTW, do you know they make a .006 wall thick 1/16 tubing that .047 wire fits right in to? I think you might want to possibly take a look at that concept for some chassis?

[Don Weaver]

Marty,

I tried some of that "thin wall" tubing awhile back for floppys and found that it would actually "tear" if involved in a crash (which was common for me!).

Don Weaver

[Joe Mig]

Cool Hoodoo you built there Duffy.
Did you put any angle 2 to 5 to degree of upward rake? I just don't see it in the pix.

[Duffy]

Be sure and let me know if the front clearance turns out to be perfect after the wheels are installed. No cheating by multiple Hudy trimmings; I want you to tell me they come right out of the bottle and clear a perfect .020

Not telling you any of the sort, O Tonsorial Minimalist Goombah. My usual JK fronts, got four of 'em here--run .7795" to .7810" for an extra .015" clearance And this neet new pair I just got, dunno the brand but they're hard as rock--WO! .7575" on one, .7650" on the other. Ummm--thanks for the reminder, Pablo, I wouldn't've thought of it. Now I'll never forget it.

See, that's why I want to do this kind of thread; not because I think I'm clever enough to reinvent a 40-year-old wheel, but because I'm arguably astute enough to want to discuss the engineering and good practice that I and we may find important, including all those little essential points I and we may forget to mention until we see it pop up. Good for me right now, maybe good for someone else who'll read this at some point where he hasn't yet established habits firmly enough that he forgets he's doin 'em naturally. And this just may be the most run-on paragraph I've ever written.

Here's another one:

Did you put any angle 2 to 5 to degree of upward rake? I just don't see it in the pix.

Good call, and if you're wasting what remains of your sharp eyesight scrutinizin' my stuff, you have less of a life than I do!

No, the coining tool is just flat-turned discs, you can see it in the second pic. I just figured I'd put it in at assembly. (How would I build that cant into the tool?) Part of the problem is, the 10-32 screw in the R-Geo bracket wouldn't fit in a canted hole, my clearances are too tight. I'll bend it in now, which is its own ball of snakes but I don't see a better way. I'm hoping my hoody coined overbuild is more durable--if it's hard to bend the cant in, it may not go out as easily. The prototype used a simple z-bend in .050" stock and I was tweaking it all day...I know I know, learn to not-crash and the problem's solved.

Oh, and that pic brings up another point, from earlier:

Did 15 year old Duffy cut that nose piece out with a coping saw or did older Duffy machine that out after work?

15-yr-old Inner Duffy grudgingly admits my sawing job is sufficiently sloppy--see the nearside plate looking crooked? It ain't just parallax distortion!

I scribed up four of these nosepieces to cut out; considered stacking and machining, considered all those setups grabbed in precious lunchbreak time at the shop, and just went "Wait...why?..."

See, there's a tradeoff here. Some processes, the amount of setup and planning needed to achieve a level of accuracy you're trying for--naww, saw file & measure and in the space of a cup of coffee you're on to the next thing, all in the comfort of your home.

I don't know where the line for that is for everybody. I know I've erred on both sides of it myself plenty times.

Duffy

[Tex]

Nice chassis, Duff. The last thoughts you posted are very telling. We can spend a lot of time, I mean a LOT of time, trying to engineer the PERFECT chassis in our mind, doing and redoing and remembering this trick and don't forget THAT trick, or..... just start building and let it happen. You may not get everything done on one chassis; that way, we get to build another to try out those things left undone on the first. But in the end, you have a couple of chassis' built instead of just perfect ideas stuck in your head(paralysis by analysis); you have something to PLAY with while you think of new mountains to climb. Gotta have some fun for the 12-year old, ya know?

[Marty Stanley]

Marty,

I tried some of that "thin wall" tubing awhile back for floppys and found that it would actually "tear" if involved in a crash (which was common for me!).

Don Weaver

Don,

I try NOT to use that tubing, for the reason you stated, on pans that can make contact with the wall. When I build one of the outer / inner pan chassis, I always use that tubing for the inner pans as they are protected by the outer pans during unfortunate incidents!

Pablo likes to build main rails out of .062 wire inside of .093 square tubing. I was suggesting he try some .006 1/16 tubing with .047 wire soldered inside for his main rails. I have a chassis in my mind this morning - I'm starting to come up with ideas for chassis now in my sleep - that will use that technique.

BTW, I still have my 'Official SERRA Brenda's Sausage Biscuit Plate" sitting right on my build area. Alas and alack, it is empty and void of those succulent little sausage creations that your wife makes. It's time for another trip to Abbeville. Probably soon as I get clearance to travel and so anything from the doc.

[Joe Mig]

Good call, and if you're wasting what remains of your sharp eyesight scrutinizin' my stuff, you have less of a life than I do![/size][/font]

No scrutiny here I was just trying bring something to your attention.

[Duffy]

No scrutiny here I was just trying bring something to your attention.

And I was having fun with you. Start to finish.

[Joe Mig]

And I was having fun with you. Start to finish.

Fun is what it is all about.

[Pablo]

Pablo likes to build main rails out of .062 wire inside of .093 square tubing

Wrong. And it ain't that simple.

Also, for anybody who may be curious, I was trying to convince the Duffmaster of setting up the front axle assembly in a manner where one would be able to PRECISELY set, and be able to adjust, the EXACT front clearance of the chassis. It is extremely difficult to secure the axle beforehand and have the clearance end up perfect. But of course somehow his method worked so I cannot fault it.

[Duffy]

Wrong. And it ain't that simple.

I officially invite, encourage, and sanction hijacks, creep and drift in MY thread. Go for it.

Also, for anybody who may be curious, I was trying to convince the Duffmaster of setting up the front axle assembly in a manner where one would be able to PRECISELY set, and be able to adjust, the EXACT front clearance of the chassis. It is extremely difficult to secure the axle beforehand and have the clearance end up perfect. But of course somehow his method worked so I cannot fault it.

Don't be quite so quick, Glosstop, I just used jig wheels for optimum axle setup and trusted the store-boughten tyres to do the rest. You've reminded me big-time that this mightn't be the case.

In the first iteration of HOODOO I went apespit with my wire-bending, looping both the uprights off the main rail and the font brace over the top of the axle for "maximum solder area"--the front brace was a topological conundrum that would make a Texas Longhorn blush, I swear. Well, TonyP and Pablo both gently apprised me of the time I'd have if I should ever have to make adjustments here...and I listened.

Being the micromanager of dimensions I [claim to be], my axles supply my optimum clearance; the rest is up to the tyres, and that's up to my grinding.

Duffy

[Rick Moore]

Duffy

Since Marty, Tony & Pablo have offered you their ideas, and you're actually listening to these guys, I figure you might be crazy enough to listen to me too!

On the matter of front axle mounting, there's more than one way to skin a (animal reference omitted at request of SPCA), I've got my own system of making two wire axle uprights that span the chassis fore and aft of the axle; here's a pic:



They are superstructure, not components of the chassis frame. Yes, there are four bends in each of them (Tony's head is probably getting that migraine thing again…), but they're not that hard to make and all I use is needlenose pliers and a vise. They're angled for better stability and strength. The axle just drops in between them at the desired height, and is soldered along the width of the uprights. Makes replacing a bent front axle (or even the uprights if things got really really bad) quick and easy should the need ever arise.

Rick (aka CMF3)

[Pablo]

More than one way to skin a stray cat ? Yes.
Is it strong ? Yes.
Is it simple ? Yes.
Is it easy to adjust the clearance precisely ? Yes.
Could you have a complete spare axle/wheel assembly ready to go and change it out quickly ? Yes.
Will it bend before it breaks ? Yes.
If it breaks, will it ruin other components ? No.

Rick, together maybe we can convince him In his current neapolitan state of mind, he cares not about a couple thou here or there. In time he may Then it would be "Katy-bar-the-door", Duffy is eating Chinese with his micrometer again

BTW, Rick, Duf said we could drift, so:
I may bring my chihuahua to the next Viper Pit race, so bring a muzzle for killer, I mean Joey
They may have to cage the cats.

[Noose]

Duffy,
Technical mumbo jumbo aside. Nice job dude.

[Pablo]

HOOOOOODOOOOOOOOO

[Duffy]

HOOOOOODOOOOOOOOO

Occasionally, I doo.

A bump-up, partly, and first shakedown impressions:

Got this chassis out on the track a little this weekend; didn't have time to resolve guide-height to SAL's King track--I got my wish, made that tongue so strong I can't even bend it on purpose!!--but a few minutes doing laps reveals no glaring challenges. Car seems to run just like HD1, only hotter with the Puppy Dog in it. I'll get over next week and work more with it. Happy so far.

And now, a crisis. I put it here because this thread's already going, because it's MY thread anyway & I'll do as I damm please with it, and because I'm Duffy that's why.

Which in a way IS the crisis:

A friend sorta dropped on me today, "You know--in Racing, it's considered bad luck to knowingly take another racer's nickname.
"Just, y' know, FYI...
"...I mean, since you're still in the process of becoming fast, I just thought there might be REASON..."


Ah. I did not know that.
--Soo, I may be struggling under a Karmic cloud here? My famous lack of skill, my well-earned Track Cred as Grenade On Wheels may have a Cause, and a Curse? BAD LUCK? Is this even possible? (Can I have an Excuse, besides I'm-just-a-pi$$poor-driver??)

But, still, what can I do about it?
See, first, I came home and tried to find confirmation that "Duffy" is really a Nickname. (It turns out, Is. Frank "Duffy" Livingstone. Darn.)
Then, I thought about playing The Semantics Game. (Well, the key is "knowingly" as in, I didn't adopt the nickname knowing it would bring me bad luck! --No? Okay, no. Darn, again.)
Well, hmmmm.

AH! I got it:
It's not really that Duffy.
Nope, sounds like but no. Uh-uh, no similarities here. Pay no attention to that polkadot helmet behind the curtain. Because--
--because I took the name from one of my musical heroes, late-Medieval / early-Renaissance hotshot Guillame DUFAY.
No, really. Great guy, Dufay, played a lot of his stuff back when I could play. So, naturally, in my waning years I vainly co-opt his name to remind me of the excellence I contiinue to strive for. And it ain't no NICKNAME, Jack, that's a durn SURNAME.
And, everybody knows they hadn't standardized spelling in the Renaissance, right? (e.g. "Shakespeare, Shake-Speare, Shaxper, Rattle-Speare, Bacon...")
Ergo:
DUFFY.
Pronounced. Duh-FIE. Or, well, however. We haven't standardized pronunciation in modern-day Brooklyn. Say it, y' know, As You Like It.

Works for me. Okay?

Duf

[Marty Stanley]

We haven't standardized pronunciation in modern-day Brooklyn. Say it, y' know, As You Like It.

Duffy,

I never knew that Brooklyn ever had a standardized pronuciation! Aside from the day that the Dodgers left Brooklyn for life on the left coast in a ravine, I've never heard anything from Brooklyn, other then phrases like "Youse Guys". Okay, so most names are prefaced with terms like "Yo", like in "Yo Tony" or "Yo Joe" or the more famous, "Yo Vinny" - that usually gets the majority of the people gathered anywhere in Brooklyn to turn and ask "Wha?" About the only other name with as much popularity in the world is "Bob". I remember one time when I worked in an office with 3 guys with the name of "Bob". I found it quite easy to get any of them, all I yelled was "Bob" and they all came running.

Now on nicknames . . . . I had heard that you were being called "Roadblock" at one time by your fellow racers. I have no idea what they meant by that!

Rather then bending, you might want to try the more effective washers between the guide tongue and the guide flag!

[Duffy]

I never knew that Brooklyn ever had a standardized pronunciation!

Nope. But now, "Yo [ Kaz, Ahmed, Jesus, Kareem, Bruce ]" will get you just about the same result. It's a Polyglot Hipster Mecca these days, B'klyn is.

Now on nicknames . . . . I had heard that you were being called "Roadblock" at one time by your fellow racers. I have no idea what they meant by that!

Yes you do. Thanks; but you do.
Yup, I'm the freekin' Slots Kaopectate, I am.

Rather then bending, you might want to try the more effective washers between the guide tongue and the guide flag!

Yah, but in this case it's the opposite, I didn't coin deep enough and I need juuuust a little more. Soon.

Dew-Fie