I am just wondering as to what constitutes scratch building .
I have used Penelope Pitlane Chassis's. RM and BD lol. I've even made some brass ones. I see now plastic or abs 3d printed components available, such as front carriers, motor and rear axle cradles, all to be connected by brass tube or rod.
It pretty much takes the skill out of brass chassis building, but then I suppose so does the PP chassis. I use resin bodies and build them up and try to replicate as much as my skill set allows, and I can build a basic brass chassis.
Are there any given rules or guidlines as to what is or is not scratch built.I really enjoy this aspect , but wonder if the new components are still in the scratch category.
I posted this over on the Slot Forum but then thought that it might be of interest here. The particular examples are not both open wheel cars but the idea is general.
When I first got into slot cars (late 50s) there was really no choice except to build one's own chassis. Commercial RTR cars were few and those that were available were really rather toylike. For a variety of reasons I focused on 1/24 cars motorizing available plastic kits. I left the scene in the early 60s before the explosion of commercial tracks and sources.
With the exception of a brief period in the early 80s spent reviving an old Scalextric track and discovering all of the cars and parts that had evolved in the preceding 20 years, I was inactive until about 1995.
When I joined a local group in 1995 I was in for a few surprises. I had never seen a car fitted with a magnet. The speed and road holding were astonishing. I bought a few cars and joined in. As the group evolved, we moved away from magnets. The Internet brought me into contact with was going on in the rest of the world.
My experience with the RTR cars of the day served to reinforce my long-standing dislike of plastic wheels, gears and chassis. Wheels fell off, gears stripped and chassis broke. My interest in chassis building was rekindled. I was quite convinced that I could build a better chassis and thus a faster car. My workshop was augmented with a small lathe and a small milling machine fitted with 3 axis digital readout.
In those days it appeared that my belief was vindicated. A whole collection of cars with machined chassis using center pivots and spring wire rails was constructed. None of them had magnets and they enjoyed significant success.
As the years went by it became clear that the advantage that these cars enjoyed over the newly available RTR cars with movable/adjustable motor – axle assemblies was diminishing.
I like proxy races because in a typical, well-run proxy race one sees the results of a range of competing cars handled by the same driver in a given race. (It also removes the factor of my driving versus that of the others in our group) the first foreshadowing of my current observations occurred in a proxy race 6 years ago. The cars were 1.5 L F1 cars. I had entered one of my typical twisting sprung chassis with machined brass rear assembly etc. The car performed well (as I recall it even won one of the races) but at the end of the day winners honor with a series went to a car that had a carefully built but simple "fold up" commercial chassis.
At the same time – over the past 10 years or so – I have found it exceedingly difficult to build a chassis that can offer any significant advantage over the best of the commercially available RTR chassis especially when their performance is further enhanced by a variety of aftermarket bits and pieces.
I have been mostly inactive for the past couple of years for a variety of reasons. A relocation and a necessary consolidation of my workspace dictated the sale of my milling machine. (It was my intent to replace this rather large machine with a smaller unit fitted with CNC capabilities – for reasons outlined below this plan has been put on hold)
My first priority after reestablishing it workshop was to build cars for 2 proxy races. These cars were sent off untested because my track was also a casualty of the relocation. I've been following the results of these contests in these results are changing my way of thinking. In one case, my car is doing very poorly. It is contesting last-place honors with cars that are either DNS or DNF. There may be a variety of reasons for this – I'm suspecting among other things that I made a poor choice of motor for this (unusual) free motor choice race. What has really caught my attention is the fact that the current leader, a car that has been placed 1 or 2 in races and qualifying, is built on an (undoubtedly well executed) simple "fold up" chassis. In a 2nd instance, my entrant is doing somewhat better as one might imagine it should running a sophisticated spring steel plus rattle pan chassis. The leading cars in this race are, however, what I believe to be carefully set up and tuned versions of commercial RTR cars complete with original plastic chassis!
What's going on here? Am I a dinosaur looking up at the meteorite rushing towards the earth? I think there may be an explanation and I'm going to offer one for discussion (or disputation)
Traction is always an issue. One side of the slot car world, those looking for speed at all costs, have adopted very wide foam tires, aerodynamics and in some cases sticky stuff on the track to avoid wheelspin on the straights or loss of control in the corners. Those of us in the "scale" hard body world have used magnets and weight to achieve control. Magnets have fallen out of favor and the increasing instance of motor rules make the use of weight a two-edged sword.
I was first introduced to Ortmann tires by Phillipe DeLespinay at one of the early Las Vegas slot car conventions. I put a set of them on one of my old 1/24 cars and the effect struck me as close to magical. Of course, urethane tires are now in routine use everywhere. My theory is that the superior traction of urethane tires significantly changes the relative importance of various aspects of chassis function. (This effect can be taken as similar to the ability of magnets to at least partially hide defects in the older plastic chassis) . The basics are still important – wheels and tires need to be round and square on the axles, the chassis needs to be square, gears must mesh properly, the guide will set up and the laws of physics with regards to the distribution of mass must be obeyed. Track with will always be important and wheelbase/guide base will have an effect. That said, it appears to me that once these "basics" are attended to, the overall mass and distribution of that mass is more important than the tricks and twists of other chassis functions.
My take away all of this? I have just ordered several examples of what I refer to as "origami chassis."
Post by Phil Kalbfell on Oct 24, 2016 19:13:20 GMT -5
Great observations Al, and so true. I have been building chassis since the sixties, but late last year my Grand Daughter wanted to build a complete car. She spotted a fold up chassis here and wanted to have a go at it. With some instructions she folded it up very carefully, used my resistsnce soldering station and in an afternoon had a completed chassis. Over the next few weeks she assembled it up very carefully, listening to my comments.! The car was entered in the Tasmsn Proxy series and won the event! Beating all the scratchbuilts. Why? Mainly because it was easy to drive and very well assembled. If a very patient 16 year old can do this then just imagine what an experienced constructor can do! I still like building chassis and take pride in doing it,but is all the time and effort with it? For some class's of racing yes, but for these little F1cars the origami chassis are certainly a great option.