Your progress is absolutely astonishing and this car looks like its going to be a beauty. Can't wait to drool over it at the track. Good luck with the rest of the work. Can't wait to see it all finished.
Your progress is absolutely astonishing and this car looks like its going to be a beauty. Can't wait to drool over it at the track. Good luck with the rest of the work. Can't wait to see it all finished.
Really great stuff Jon. Please keep posting pictures.
I am curious. I see the finished plug, and the great looking bodywork, but did you make female mold? If not, how did you get the finish on the parts?
Between you and Devins there must be something about Michigan and great composite work.
Jim
In the past Jon has used a male mold (sometimes using old bodywork) with three 6 oz layers of cloth - then a mix of 410 Microlight and epoxy to fill the exposed weave.
I think the key here is patience to work all the air bubbles out of the layup. It certainly makes a lot of sense if you have the skill.
Article can be seen here
http://www.westsystem.com/ss/project...on-staudacher/
Mark Silverberg - SE Michigan
Lynx B FV & Royale RP3 FF
240Z Vintage Production Car
PCR, Kosmic CRG & Birel karts
Jon
Was just looking at the pics of your uprights (posted earlier in the month)
- do you press the wheel bearings directly into the aluminum
- - - or via steel 'sleeves' (ala Stohr)?
- do you use 6061 to machine them (which most of us can just about afford)
- - - or 7075 (which most can't)?
Thx - Derek
Last edited by dereklola; 01.28.13 at 10:08 PM. Reason: speeling
uprights
Derek,
The bearings are pressed into the aluminum. 7075T6. About .0035" press fit.
Jon
Jon,
Just a question on those wings of yours.
Are they made with a thin ply wood skin over the ribs?
How do you adjust the front wing angle as it looks as if it is attached directly to the underside of the nose.
Nice workmanship.............including the house!
Desmond
Liked Jons upright design so much....
...That I blatantly copied them!
Wings
Desmond,
Yes, the wings are covered with plywood 1.5 to 3 mm thick. Some birch some okoume.
You are right about the front wing not being adjustable, but it will have flaps (second elements) that are.
Jon
Looks Great Jon. Looking forward to seeing the finished machine. I have mine being built now and look forward to being on the track in June.
Jason
Would have said owner been Mike Weinert?
Looks amazing Jon! I have always been amazed what you can do with a race boat and cars! They are all top notch! I am proud to say i have been able to drive one of your race boats! Maybe some day one of your cars! Awesome work like always!
Brandon Kennedy
Final assembly
Here are a few photos of my FB as I assemble it. I streamlined the round tubing used in the A arms with wood. A wood sample is shown in a photo. I did the pushrods too.
Jon
Jon adds "photo art" to his list of talents...
Stan Clayton
Stohr Cars
Aero
Jon,
I was hoping for teak and holly laminated wood aero farings with 6 coats of varnish.
Sorry I am a former sailboat racer and love teak and bright work.
Incredible.
What will be your first outing?
Single Shear
Hmmm - single shear all over the place - with 'normal' size bolts and thin attachment locations.
I need to go back to school to relearn something.
Jon,
Beautiful work. Regarding the steamlined tubes, is the wood glued to the round tubing? Or are the tubes shaped with the aid of the wood?
Thanks,
Barry
Single Shear
All of Jon's DSRs were built that way. I don''t recall hearing of a single (ha ha) failure.
Marty
single shear design
I learned that double shear is the preferred method---but most importantly, I've never designed a car. Perhaps all these fasteners in single shear are actually much larger than needed if designed in double shear and therefore up to the task under normal conditions + x% safety factor. In the event of an impact, perhaps the fasteners will shear minimizing damage to other harder/more expensive to replace components?
Is wood legal on suspension parts?
Just curious, how do you justifiy compliance with 9.1.1.G.9.A which states:Originally Posted by JONKATHY
All suspension components shall be of steel or ferrous material, except that hubs, hub adapters, hub carriers, bell cranks, pivot blocks, bearings and bushings, spring caps, abutment nuts, anti-roll bar links, shock absorber caps, and nuts may be aluminum alloy or magnesium alloy.
The only allowances I see for wood are composite bodywork stiffening and skid blocks.
David, I suspect that Jon is saying he used wood(en forms) to ovalize the round (steel) tubes...not that he has wood tubes.
Stan Clayton
Stohr Cars
Looks to me like he added wooden trailing edges to the steel suspension components.
Hmm, now that I reexamine the photos, you may well be right.
Stan Clayton
Stohr Cars
If it were my car I would argue that the wood is a fairing not load bearing. We allow paint and also fiberglass trailing edge covers so why not a little wood. I may not win but I can not imagine that I would lose since it meets the intent as far as safety goes.
wood
Pound for pound wood is stronger than steel. ... I think
While the use of wood as a fairing material is unique, I would doubt that it would be considered illegal. The basic test as to whether or not something is "suspension" is to remove it and see if the suspension collapses. Since these fairings are purely decorative, their removal would not compromise the suspension, and therefore would not be considered 'suspension".
If we had steel strip and a wood strip of the same width that have the same wright per unit length, then pound for pound the wood strip will be stiffer in bending loads. This is because the increase in thickness. However, in a pure tension load, the steel is much better. Likewise, if we try to compress the strip, the thin steel is going to buckle at much lower loads (unless the strip is very short).Pound for pound wood is stronger than steel. ... I think
I wonder how much the wood adds to the buckling strength of the suspension tubes?? Very cool idea. If the parts are not suspension, then would they be subject to a bodywork width rule?
single shear
i LOVE this guy's work but those single shear attachments just look wrong...just saying
I don't think so, but I'd have to look again at what the class defines bodywork to be ( we set a definition in the revised FF/FC rules). If there is not a class-specific definition, then they would be subject to the Glossary definition.
The single shear inboard attachments don't bother me too much, assuming that the bolts used are strong enough (even tough such practice is frowned upon_. What I would question is the lower outboard ends - eg - whether or not the rod end used is strong enough to take both the vertical and the braking loads at the same time. They look like 1/2" rod ends, and we used to bend them under braking on an FF when they were the outboard end of the upper a-arm and hung out past the jamb nut a bit too much.
Last edited by R. Pare; 02.23.13 at 5:00 PM.
Geez, Dustin. Did you create your own personal unit of measure now? The existing choices weren't up to your standards?
Load calculation
Here's the load calculation for the lower outboard pushrod attachment:
Highest corner, vertical load: 300#
Pushrod load (30 degrees)=1.67x300= 500 #
Spring: 350# max
Bump resistance: 100# at 12"/second
Motion ratio: 1.56
Suspension travel: 1.5"
Maximum pushrod load = 500+[350+100x1.67x(1.56 squared)]x1.5=3570#
Or, with no bump resistance=2634#
Pushrod column strength=2600#
Bearing strength of .375" hole in .120 thick 4130 plate=4500#
Single shear AN6 bolt=8250#
It appears the single shear attachment is not an issue. This arrangement has been in service on 5 cars since 2004 which is encouraging but, of course, no guarantee.
To answer Michael Crowe's question: I intend to run my sports racer during the coming seasaon and only test/race the FB as time allows.
To answer Richard Pare's question: The rod end in question has a 5/8" shank.
Thanks for everyone's interest. Jon
I agree with Richard - especially on the lower outboard front rodends. I broke a 1/2" UPPER rodend in the rear of an RF93 last summer. The lower front outboard rodends in single shear in Jon's design are taking quite a braking load, especially in a fairly high downforce car - and add in the torque moment from the outside of the front tires. It's a bending load rather than strictly a shear load.
Errr.. Whoops. Weight.Geez, Dustin. Did you create your own personal unit of measure now? The existing choices weren't up to your standards?
I think you are underestimating the loads that are possible.
Let's assume that the car has a 45% F/R weight distribution. Car is 1000#, so each front caries 225# static after a race. Dynamically the car might generate 1000# down force at 150mph. That corner weight is now 450#. That is before I brake or corner the car.
Now let's assume a 125 mph corner, 2 degrees banking, 2.5G lateral force. The total loading on the chassis will be 2110", 1416 # normal force and 694# aero loading. That translates to 718/887 # on the outside wheels. That does not account for any additional loading for bumps.
Your numbers are correct but you are under estimating the potential of a FB. Use these numbers and calculate what your safety margin is for the front lower ball joint/ rod end.
On another subject, I don't think that wood is in the list of materials for suspension components. Therefor the wood would be a fairing. But because it moves with the suspension, is it not a moveable aerodynamic device? And the last time I checked thaat was not legal.
Steve if that is correct then aero tube would have to be illegal as well. I believe that as long as the section is symmetrical and has no angle of attach you should be fine.
Aero tubing is steel tubing. Steel is an approved material for suspension components. Wood is not. Nor are composites of any kind.
This is the 2013 GCR:
9. Suspension
All suspension components shall be of steel or ferrous material, except that hubs, hub adapters, hub carriers, bell cranks, pivot blocks, bearings and bushings, spring caps, abutment nuts, anti-roll bar links, shock absorber caps, and nuts may be aluminum alloy or magnesium alloy.
my point was about the shape being a movable aero device - the material issue is a separate conversation. My thought is that if the shape is not legal then it would not matter what material it is made of and therefore aero tube would be illegal, hell it's even called aero tube!
I have seen NUMEROUS cars with aero shaped aluminum covers over the brake lines. If any kind of additional covering for a control arm is illegal then every one of those cars with aluminum shields are also illegal period. I personally do not think this is or should be considered illegal. Just because it moves with the suspension does not mean that it is suspension. Remove the aluminum cover or the wood and the suspension still works without a problem. This is the kind of issue that gets blown out of proportion IMHO.
Jon has created a very low cost solution that makes a lot of sense for club racing. We should all applaud him instead of trying to say that he is not legal.
Thanks ... Jay Novak
Corner Weights
A small point. Steve said "Let's assume that the car has a 45% F/R weight distribution. Car is 1000#, so each front caries 225# static after a race". I think that in truth that each front suspension carries the sprung portion of that 225#.
Marty
OK so let's assume that you can not use wood - how will the scrutineers be able to tell if they are in fact made or wood?
As long as someone has a duck and a good set of scales it should be fairly simple.
and now for something completely different......
http://www.youtube.com/watch?v=yp_l5ntikaU
They would have to consult the manual to determine that....
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