1910 Sears Motor Buggy

[kenlwest]

To all,

Early Automobile subjects are not very common in this forum.  Having worked in Automotive Design for over 35 years, I have always been intrigued with the innovation and development that these early subjects brought to the market.  The Sears Motor Buggy has an interesting story that I hope to tell through this thread.

The Sears Motor Buggy was produced from 1908 through 1912.  The predecessor to the Sears Motor Buggy was the Krotz Motor Buggy.  Alvaro Krotz was an innovator and entrepreneur who left his mark on several industries including telephones and automotive tire development.  When Sears Roebuck decided to get into the auto business, they partnered with Krotz to build the car, and renamed it the Sears Motor Buggy.  Here is a link to the Krotz/Sears story.

https://www.hemmings.com/stories/article/alvaro-krotz

I hope you will find this an interesting build.  There is enough information out there to build a reasonably accurate model. 

[kenlwest]

Starting with Frame...  there were several variants of the Sears MB, and the length of the frames were modified accordingly.  Here is a picture of a completed chassis for reference.  

[peteski]

That is a very unusual and interesting subject.  Is the model designed in CAD and 3D printed?

[Richard Bartrop]

Definitely looking forward to seeing how this one turns out.

[NOBLNG]

Interesting build.?

[Bugatti Fan]

Veteran cars have been very under represented in kit form over the years. The only ones I can think of were made by Airfix, Revell and Gowland way back when in 1/32nd scale mainly. Aurora did a few in 1/16th scale plus one of two other kits of Japanese origin who I cannot remember. The very latest kit is of a vintage Mercedes in 1/24th scale by ICM that has photo etched wire wheels that I can think of. Not much market for them I guess.

However, it is a refreshing change to see a scratch build of this Sears car taking shape. Nice thing about most veteran cars is that the chassis and bodywork are mostly quite angular. The wheels present the biggest challenge on tnem.

[GLMFAA1]

The old Wil-O-Line wooden fire engine kits had the wheels. a little heavier spoked but right diameter. Looks like these in this photo are repros as I don't recall them in clear. Years ago Jim Etter cast repos in pewter. Interesting build, always fascinated by the power trains in the original automobiles.

greg

[peteski]

2 hours ago, Bugatti Fan said:

Veteran cars have been very under represented in kit form over the years. The only ones I can think of were made by Airfix, Revell and Gowland way back when in 1/32nd scale mainly. Aurora did a few in 1/16th scale plus one of two other kits of Japanese origin who I cannot remember. The very latest kit is of a vintage Mercedes in 1/24th scale by ICM that has photo etched wire wheels that I can think of. Not much market for them I guess.

True.  There are also other models of the early 20th Century vehicles in smaller scales.  Micron Art (no longer in business) produced several photoetched brass models of such vehicles in N scale (1:160).  I built their Knox Fire Engine.   See https://nscalevehicles.org/galleries/2/knox_fire_pumper.php  for photos, and  https://nscalevehicles.org/tips_n_tricks/micronart_knox_fire_truck.php  for construction details.

[Bugatti Fan]

Never heard of Micron Art kits Pete. Fascinating little model you posted.

Your post actually jogged my memory about some exquisite little plastic kits by a company named Jordan Miniatures. As it was a fire engine it made me think about many years ago that I had their Mack Ladder Chief and an Ahrens Fox Pumper. I wish I had not sold them on now. I think the kits were American in origin and I believe that Jordan had a nice range of those miniature kits. Not sure if they were N gauge or HO/OO gauge as they looked like they were made to place on railway model layouts as well as being lovely little models in their own right.

Either yourself Pete or other readers might know more about Jordan Miniatures and Micron Art kits.

Edited August 12, 2023 by Bugatti Fan

[Danno]

The Jordan kits were HO scale - marketed for use in the most popular model railroad scale. 

 

Question:  Did Alvaro call his souped-up version the Krotz Rocket?    ?

 

 

[kenlwest]

On 8/10/2023 at 10:18 PM, peteski said:

That is a very unusual and interesting subject.  Is the model designed in CAD and 3D printed?

Yes, CAD and 3d printed.

[kenlwest]

The first set of engine parts.  Starting at the top, the 2 crankcase halves (cylinders were casted with the case), flywheel, friction plate, case cover, intake pipe, carburetor, and starter engagement cog.

[kenlwest]

The rest of the engine parts:  

Front engine cover and valve boxes, flywheel shield, spark plugs and fill cups, fan drive belt and pulleys, cooling fans, and cam boxes.

[kenlwest]

Main engine assembly:  I used a spring from an ink pen to represent the valve return springs.  Also, a picture of the real engine.  The 2 cylinders are not offset to accommodate individual crank journals.  However, the connecting rods are offset.  I have never seen this on any other engine.

[kenlwest]

Engine assembly so far:  the resin parts tend to be heavy, so I need to find a way to make the suspension parts strong enough to support the weight.  Normally this would not be a problem on modern cars, but these cars are very fragile in small scale.

[Richard Bartrop]

Maybe go with something like brass for the suspension?

 

[absmiami]

Are you familiar with fusee chain ?

[kenlwest]

9 hours ago, Richard Bartrop said:

Maybe go with something like brass for the suspension?

 

That would work, but I don't really have the tools or skills for that.  I have seen some really great work with brass on this forum though!

[kenlwest]

32 minutes ago, absmiami said:

Are you familiar with fusee chain ?

Not familiar with it.  Is it a brand name?

[kenlwest]

I added the cooling fans, pulleys and cam boxes.  Here is a picture of the progress, carb and flywheel.

[Deathgoblin]

I dig it!    Following this one.

[kenlwest]

A quick preview:  the seat and body sitting on the frame.  At 1:8 scale, the width of the body and frame measure 4.5 inches.

[peteski]

20 hours ago, kenlwest said:

That would work, but I don't really have the tools or skills for that.  I have seen some really great work with brass on this forum though!

I find it interesting that you are perfectly at home in a virtual (CAD) world, but don't have any hands-on modeling experience working with metal.   You produce some amazing 3D designs, and I have a feeling that you could likely get out of your comfort zone and try some new techniques in the "real" world.

Actually I wish I had half of your CAD abilities to augment my hands-on skills.  I have so far only taken baby steps in CAD design.

As for fusee chain, it is a extremely fine metal chain used in antique clocks and watches.  It can be used to represent scale chain in model  motorcycles or other chain driven vehicles.  There is no brand name I know of.  There are sellers on eBay who sell fusee chain.

More info about it is at https://en.wikipedia.org/wiki/Fusee_(horology) 

Edited August 16, 2023 by peteski

[absmiami]

What he said - but actually the chain - which was used in pocket watches - is too small for a large scale drive train - oh well …

[Bugatti Fan]

Was unaware until later in the this thread that the model is both 1/8th scale and drawn up in 3D CAD and then 3D Printed.

Must have access to quite a large printer to make the chassis and seat etc. Interesting project and subject. 3D CAD and printing have revolutionised the model making process for many these days whether private individuals or a cottage industry.

In the case of the cottage industry, no more master and mould making, mixing of resin and limited to when the moulds give up. No more wastage when parts come out with blow holes or distortion etc. To a certain extent for the private individual or industry you are designing and producing your own kit or parts that can be repeated ad infinitum with consistency.