Suggestions Sought for New Chassis Design

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goatdope
Posts: 32
Joined: Tue 28. Jan 2014 19:53
Location: Lansing, Illinois, USA

Re: Suggestions Sought for New Chassis Design

Post by goatdope » Mon 25. Jan 2016 00:41

To Ned regarding "front end shimmy". You could try adding some weight. All my cars weigh at least 3.5 ounces. More weight in the front makes the car more responsive to lane changes. Ken.

Ned
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Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Suggestions Sought for New Chassis Design

Post by Ned » Mon 25. Jan 2016 16:24

Ken, Thanks for the tip about adding weight to front end to reduce front end shimmy. I'll try that.

The specs for a stock mag car chassis, with stock wheels, are as follows:
base frame width 2.135”
front track 2.060”
min rear track 1.910”
wheelbase 3.000”
The front and rear track can be reduced a little by reducing the width of the wheels and of course the rear track can be increased by using washers/spacers on a longer rear axle.
Assuming a scale of 1/32, then the full scale (1/1) equivalent numbers with stock wheels are:
base frame width 68.3”
front track 65.9”
min rear track 61.1”
wheelbase 96.0”

I have designed a chassis with an adjustable wheelbase having the following numbers with stock wheels:
base frame width 2.000”
front track 1.925”
rear track 1.850”
wheelbase 2.75” - 3.375”
Assuming a scale of 1/32, then the full scale (1/1) equivalent numbers with stock wheels are:
base frame width 64.0”
front track 61.6”
min rear track 59.2”
wheelbase 88.0” - 108.0”

My chassis also has a lower side profile so that it requires less vertical clearance to fit under a body as well as 8 different mounting points to accommodate the interior/underside of many different bodies, 4 mounting points in front, 2 in the middle, and 2 in the rear behind the axle. It also will have about 1-2 degrees of positive toe and maybe a slight bit of negative camber when finished. I have had one prototype printed and I’m in the process of tweaking the design. I expect to have it complete by March 1.

Would this chassis meet your needs? If not, what specs would?

kiklo
Posts: 175
Joined: Mon 9. Nov 2015 11:49
Location: Norway

Re: Suggestions Sought for New Chassis Design

Post by kiklo » Tue 26. Jan 2016 08:31

This sounds promising.
One thing I have in mind is rear axel dim. I have managed to bend the std. 2.mm(dropped off the table), I would consider using 3.mm, and bushings like other 1:32 scale systems. It would also give us a wider choice of supplies. But then you would move away from WES's origin.
Racing Regards

Kim K.

Ned
Posts: 314
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Suggestions Sought for New Chassis Design

Post by Ned » Wed 27. Jan 2016 02:02

Thanks for the feedback Kiklo. For the time being I'm going to focus on designing and producing two or three 1/32 scale chassis with adjustable wheelbases. To keep it simple and the cost of converting low, I'm trying to use as many standard chassis parts as possible. If I decide to design a 1/24 scale chassis, I'll definitely use a heavier and popular slot car axle size.

Ned
Posts: 314
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Suggestions Sought for New Chassis Design

Post by Ned » Fri 19. Feb 2016 01:20

I have completed my first chassis with an adjustable wheel base, narrower frame and tracks, and slimmer/lower side profile. It will fit 4 of the 5 bodies shown in my original post which started this thread. The specs of the chassis are indicated on my post of 25 Jan, 2016. This chassis does not yet fit the white 1965 Chaparral 2C. The frame still needs to be a bit narrower and the side profile a bit lower.

This one runs like a champ. No front end shimmy at all. Not even at the end of my 24’ long straight. Lane changes are more reliable than any of my other 5 cars. I think that the lack of any front end shimmy is primarily due to the fact that the front end is designed with 1.7 degrees of toe in (positive toe). Secondly, I eliminated much of the front wheel wobble by eliminating most of the taper in the stock front wheel bore. Reduced wobble may also contribute to less front end shimmy.

The white chassis below was printed by Shapeways.com from a 3D model I created. The grey chassis is a stock chassis. Regular #2 steel self tapping screws are used to attach the body to the chassis instead of stainless steel screws. This eliminates the need to glue magnets on top of the screw heads and makes future adjustments of screw height very easy. Also makes it easier to change bodies.

Image

Image

This chassis uses a lot of standard magracing parts, including the front stub axles and axle carriers.

Image

Image

As you can see in the photo below there is quite a bit of room to slide the motor/axle pod forward and thereby shorten the wheelbase. The excess length of the base frame was trimmed off at the tail end in this case. If it had not be trimmed off, the wheelbase could have been stretched to 108” at full scale, 12” longer than the stock chassis.

Image

Needless to say, shorter more flexible wire would help keep it out of the way of the car’s interior. Ideally all of the wiring would be level with or below the top of the battery box.

The chassis you see here is being fitted to my red Fly 1970 Ferrari 512S. I’m using the Fly rear wheels. Eventually want to use the Fly front wheels.
I plan to make another similar chassis which is even narrower and thinner to fit the Chaparral 2C. It will also have larger diameter pins at the ends of the steering plate (tie rod) for increased strength.

Let me know if you have any questions.

kiklo
Posts: 175
Joined: Mon 9. Nov 2015 11:49
Location: Norway

Re: Suggestions Sought for New Chassis Design

Post by kiklo » Fri 19. Feb 2016 09:58

This looks great.
Will you make it available to us? I will certainly have a couple.
Racing Regards

Kim K.

Ned
Posts: 314
Joined: Sun 13. Apr 2014 01:02
Location: Sedona, AZ USA

Re: Suggestions Sought for New Chassis Design

Post by Ned » Fri 19. Feb 2016 12:57

I'm interested in partnering with Wes to offer this new chassis as a kit with all of the parts needed for assembly and mounting to a body. Would also like to offer it as a ready-to-run chassis and perhaps a ready-to-run car, with injection molded & detailed body. I've also considered offering a slot car to mag car conversion service, whereby people short on time or talent, mail their 1/32 slot car body to me and I send it back to them ready-to-run as a magracer. Do any of you think one or more of these 4 ideas would be of interest to anyone currently involved with or contemplating this hobby?

If Wes and I don't team up on this, I'll at least make the 3D printed parts available to everyone via Shapeways.com .

On a related matter, the width of the frame between the front and rear wheels could be reduced further by .08" (about 2.5" at full scale), by shortening the battery box so that it would hold only unprotected 10440 batteries. It would easily fit a Chaparral 2C then, but you would not be able to uses protected batteries. Which would you prefer, a narrower frame using unprotected batteries or a wider frame which would accommodate protected as well as unprotected batteries? Do many of you use protected batteries in your cars?

Jeee
Posts: 48
Joined: Tue 5. May 2015 07:32

Re: Suggestions Sought for New Chassis Design

Post by Jeee » Fri 19. Feb 2016 17:40

Ned wrote:I'm interested in partnering with Wes to offer this new chassis as a kit with all of the parts needed for assembly and mounting to a body. Would also like to offer it as a ready-to-run chassis and perhaps a ready-to-run car, with injection molded & detailed body. I've also considered offering a slot car to mag car conversion service, whereby people short on time or talent, mail their 1/32 slot car body to me and I send it back to them ready-to-run as a magracer. Do any of you think one or more of these 4 ideas would be of interest to anyone currently involved with or contemplating this hobby?

If Wes and I don't team up on this, I'll at least make the 3D printed parts available to everyone via Shapeways.com .

On a related matter, the width of the frame between the front and rear wheels could be reduced further by .08" (about 2.5" at full scale), by shortening the battery box so that it would hold only unprotected 10440 batteries. It would easily fit a Chaparral 2C then, but you would not be able to uses protected batteries. Which would you prefer, a narrower frame using unprotected batteries or a wider frame which would accommodate protected as well as unprotected batteries? Do many of you use protected batteries in your cars?
I don't know the current sales numbers but from what I see on the forum the userbase seems pretty small. I suppose there must be people interested in ready to run. I think they also need a ready to run track in that case.

Looking at the number of active people and the way they stand in this hobby don't you think it is better to share the source files? (the option to add those has just been added to the forum). I think we get more progress by sharing then by everybody doing their own thing and than maybe sell one piece.....

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Lasp
Posts: 313
Joined: Wed 16. Jan 2013 16:35
Location: Helsingborg, Sweden

Re: Suggestions Sought for New Chassis Design

Post by Lasp » Fri 19. Feb 2016 19:40

The concept is alright!
You need a large space to build a right form off track. Look att Markus and Ned!
There must be some parts at a free market!
Wes R have don a good job , but there is needed a new restart! And somebody that will ...

goatdope
Posts: 32
Joined: Tue 28. Jan 2014 19:53
Location: Lansing, Illinois, USA

Re: Suggestions Sought for New Chassis Design

Post by goatdope » Tue 23. Feb 2016 15:36

To Ned Your new adjustable chassis is "right on track". However, the 3.375 max wheelbase will only be good enough for about 35% of the bodies that I currently have. My bodies are all vintage American stock cars from 1940 thru 1998. Most 60's musclecars wb are 3.5". The wb for 55 Buick , 66-69 Ford Fairlane is 3 11/16" or 3.687. Early 60's full size cars would be even longer but I could'nt find any in clear plastic. Would 3.75 be possible ? Sorry to be of such trouble but the format of the small motordrome dictates the use of stock cars. Ken.

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