Brass vs plastic chassis

dvd3500 · 16th-Sep-20, 08:13 AM

Quote:I fail to understand how somehow although we're all united in our hobby these topics tend to split opinions along the lines of a choice one vs choice two.

Possibly because things are getting even more polarized in general...

Grah1 · 16th-Sep-20, 09:26 AM

I've always tended to diversify from the norm with my chassis using many different materials ,My personal preference is brass/wire but I've never been frightened of something new .As yet I've avoided 3d printing as due to the cost of the equipment vs the amount of actual builds I do these days its not worth the out lay to me . But if that's what you want go for it I'm all for keeping the art of scratch building going .

KensRedZed · 16th-Sep-20, 08:59 PM

Like anything. It all gets proven on the track. Bad designs or builds come in last on race day.

I would not make chassis out of aluminum they weren't winning races.

Chris Walker has seen my chassis, and says they can't be more simple. But they are super square, and super flat. The machining process is idiot proof (me proof). The axles can't be out of alignment if you follow the machining textbook. The main thing he still scolds me for are the cheap bearings I use. Chris says a good bushing is better than a cheap bearing. I'm still learning.

I can beat about 80% of plastic and brass with simple aluminum because it's square. But hope to eventually breach that top 20% with a brass/wire torsion chassis. I would like to learn 3D down the road too. I'm sure we'll all be printing our own bodies when the resolution gets better.

I am still just a humble student of slot cars.

Ecurie Martini · 20th-Sep-20, 06:38 AM

(16th-Sep-20, 08:59 PM)KensRedZed Wrote: Like anything. It all gets proven on the track. Bad designs or builds come in last on race day.

I would not make chassis out of aluminum they weren't winning races.

Chris Walker has seen my chassis, and says they can't be more simple. But they are super square, and super flat. The machining process is idiot proof (me proof). The axles can't be out of alignment if you follow the machining textbook. The main thing he still scolds me for are the cheap bearings I use. Chris says a good bushing is better than a cheap bearing. I'm still learning.

I can beat about 80% of plastic and brass with simple aluminum because it's square. But hope to eventually breach that top 20% with a brass/wire torsion chassis. I would like to learn 3D down the road too. I'm sure we'll all be printing our own bodies when the resolution gets better.

I am still just a humble student of slot cars.

My first scratch chassis were aluminum (ca. 1960) but always included screw mounting for the motors. I've followed your builds elsewhere and have a question: When you glue in a motor, how do your assure that it is level, square and in line with the axle?

EM

KensRedZed · 20th-Sep-20, 12:02 PM

Hello Al,

If you look closely at the builds. You can often see a brass spacer under one side of the motor. Sometimes I get lucky with the tire diameter and it doesn't require a spacer.

I have spacers ranging from 0.005, 0.010, 0.020... etc. I install the bearings, sit the motor in place and look through the bearings to see where the end of the motor shaft sits. I test fit spacers until the end of the motor shaft sits centered through the bearings.

But there is a much better way to do this if I were to sell this chassis to the public market...

Cheers,
Ken

Grah1 · 20th-Sep-20, 01:40 PM

Ken just make a gear alignment jig. A block of square aluminium drill 2 holes at right angles one the size of your motor shaft and the other the size of your axle . Cant go wrong .

KensRedZed · 20th-Sep-20, 08:33 PM

Interesting idea Graham. Thank you very kindly for the suggestion. Thumbup

I can drill a 3/32" hole straight though an aluminum block and install it on an axle in the chassis. One 2mm hole 90 degrees parallel on one side, and a 1.5mm on the other. An inline jig for any motor. Epoxy will fill any gap. No brass spacer required.

Trouble is, how do install the pinion after the motor is glued in? The pinion goes to the end of the drive shaft when I install a motor. There is nothing extending past the pinion once it's installed. I don't use the slot in the crown to keep the axle in place. Chris Walker will be the first to say "using the slot in the crown to keep the axle in place translates to a loss of power". Words of wisdom. It's wise to listen to someone that builds winning cars.

Maybe I can use the jig to make it easier and more precise to figure out the right brass spacer, and it's position relative to the motor?

My brain is thinking on how to use this new information... I need to sit down and go through the physics.

Ecurie Martini · 21st-Sep-20, 01:26 AM

(20th-Sep-20, 08:33 PM)KensRedZed Wrote: Interesting idea Graham. Thank you very kindly for the suggestion.

I can drill a 3/32" hole straight though an aluminum block and install it on an axle in the chassis. One 2mm hole 90 degrees parallel on one side, and a 1.5mm on the other. An inline jig for any motor. Epoxy will fill any gap. No brass spacer required.

Trouble is, how do install the pinion after the motor is glued in? The pinion goes to the end of the drive shaft when I install a motor. There is nothing extending past the pinion once it's installed. I don't use the slot in the crown to keep the axle in place. Chris Walker will be the first to say "using the slot in the crown to keep the axle in place translates to a loss of power". Words of wisdom. It's wise to listen to someone that builds winning cars.

Maybe I can use the jig to make it easier and more precise to figure out the right brass spacer, and it's position relative to the motor?

My brain is thinking on how to use this new information... I need to sit down and go through the physics.

I prefer to use solder-on pinions although I use LocTite, not solder to secure them. Most generally available pinions are press-on but a 1.5 or 2mm reamer takes care of that

EM

Gordon Steadman · 21st-Sep-20, 04:34 AM

Yup, Loctite 638. Get the pinion a good but not too tight a fit, a drop of Loctite over the end nearest the shaft and slide it into 'perfect' position! I tend to use motors at the more powerful end of things - NSR Kings etc. and haven't had one let go.

Soldering is messy and, if you are not careful, gets the motor a bit warm. I see people using gas guns to solder around motors and I would be nervous of that. Maybe it's an old wive's tale but I thought heat and magnets didn't mix!

KensRedZed · 21st-Sep-20, 01:14 PM

I have 2-styles of pinions in my inventory. Press-fit and solder. I can already solder a pinion on a motor shaft so fast, very little heat runs into the motor. But I prefer not to solder pinions on short motor shafts like flat-6's, etc.

It may be possible to invent an extention to add to my pinion press to get past the axle supports.

Thank you kindly for the input. Please keep it coming. No one has a monopoly on good ideas.