Arachnid Build, ... or is it! (Highly Modified)

[Bill CNC]

(Ah-Crap-Nid) Arachnid Build, ... or is it! (Thankfully Highly Modified)

Hello Everyone.

My name is Bill and I live in the High Desert in Southern California and I am making an Arachnid (well sort of) from the plans at Spidercarts. I know their are, and will be other threads on the Arachnid, I feel that the changes (lots of them) that my Arachnid will have, ... will justify yet another Arachnid Build thread.

Although I haven't chosen the particular engine or the particulars of the independent rear suspension yet, I have started the build from the front end first and will build the rest as I go through the design phase.

This is the over all objective as of 7-31-10. These specs will change as I narrow the design down. Their is a little time to finalize everything in the rear as I work on the front.

Length ...unknown at this time
Width ... 54"
Engine ... Yamaha TT 500cc)
Drive ... 1985 Toyota Tercel differential and CV/Halfshafts. 1994 Geo Metro steering knuckles modified.
Brakes ... 1994 Geo Metro front disc brakes from 12" rims.
Use ... Off-road use, like a miniature Sand Buggy.


Any comments good or bad will be welcomed with open arms. I have never built a kart before but I am no rookie at making things from scratch. I am a Prototype/Model Maker by profession so my knowledge on what parts are available for use is were I am lacking. If any of you know were I can obtain parts from or how to do a Independent rear suspension, please inform me.

I will post pictures as I go along, some of whats on the plans, ... but I suspect most will be of the custom parts that I make.

Enjoy,


Bill

 

[r97]

parts? try here http://www.diygokarts.com/vb/showthread.php?t=1180

 

[Bill CNC]

The first modification and parts I am making are the A-arms. The bushings are what I modified for longevity, and for a smoother operation.

Here are all the parts that make up one of the bushings.

I started making the bushings by cutting up a 1." OD x 3' long steel rod into 2.250" long slugs.

I then chucked the slugs up into a lathe and bored them out to exactly.625" ID and trimmed them to exactly 2." long. I again used a boring bar and made a shoulder of .900" diameter and a flat at .100" down from the end surface. I then drilled and tapped a 1/4x28 thread for the grease fitting and de-burred everything.

I then made some washers on the lathe from Polypropylene that are 1." OD with a .625" ID and .140" thick to rest against the Silicone O-rings. I then used some high carbon steel Bellville disk spring as washers to take up any slack.

Here is what they look like completed. I wanted to use grease in the bushings, but I didn't want grease spilling out everywhere or dirt/sand getting in the the bushings. I think I have done that with this setup.

 

[Bill CNC]

Here is how the bushings mount to the front A-arms. I made the 1."x1." x 2.' long tube as per plans. I just used an end mill to cut the 1." diameter cutout for the bushings. These get welded together.

I am going to build this with independent rear suspension and I am going to make the rear end just as the front with the exception of using 1.250"x1.250" square which should be able to handle the power of the engine.

 

[redsox985]

Double post?? Those look awesome. If that what you put into the spindles, then this kart is going to be amazing. Just wondering, as I saw it in the background, does your Tap Magic ever smell like cinnamon? It's random but I noticed that while using it before (or maybe I'm nuts).

 

[r97]

if only i had a lathe....

 

[DsmEclipse]

oh the things you can do with a shop full of tools . . . . . =(

 

[theo]

Looks good, are those the pivots for a arms?

 

[Bill CNC]

Yes

 

[theo]

Bill are those red rings, seals for the grease? And is the bore through the pivot tube the same size as the through bolt?

 

[Bill CNC]

Hi Theo,

Yes the red things are Silicon O-rings and they are to "seal" the grease inside the bushing. The bolts diameter is .617" and the bushings ID is exactly .625". That will leave me with .008 for the grease.

I am thinking of cutting a .100" wide x .032" deep cuts into the bolts at .350" increments along the bolts length. This should, give me less surface contact/friction and more room for grease while still retaining more than enough strength to handle anything I could possibly do to it. In total, ... their will be 16 of these mounts for the 8 A-arms.

Anyone know of a trail for me to chase on building an Independent rear suspension?

 

[theo]

Interesting, I used the poly bushing on mine, but I like the system you are using.

 

[redsox985]

Independent Rear Suspension It's not great but there's some info here. Use the search feature too, you'll most likely find all you'll need.

 

[Silvergrizz]

Bill, Awesome work on the suspension you have done. I took another approach to the suspension (not having access to metal working tools). I am woodworker from way back. Looking forward to watching your progress as you complete your project, especially the rear suspension. I posted an update on how I am tackling the bushing issue on my thread, would certainly appreciate your insight on how it will work. Good idea to stretch the length. I am just under 6 feet and I think I am going to be a little cramped. On the other hand, my grandson might be overjoyed.

 

[brendonv]

If thats what the spindles look like i cant wait to see the kart.

 

[Bill CNC]

Well I have all the parts to the front end cut, de-burred, chamfered and ready for welding. Since I'm using flux wire I bought some Monkey Spray to control the splatter.

*** One question for those that have the Arachnid plans before I start welding, if I may;

In the picture below, ... I cannot seem to find any dimensions for the placement of the (4) 1.250" square tubing spacer upright parts #FM03-90 on parts # SB12-9045, are these just placed under the bushings?

Upper Shock mount

A-arms with bushings and mounts

 

[Bill CNC]

Hmm, ... maybe I should re-size these pictures.

 

[devino246]

This, sir, looks AMAZING! If you dont mind me asking, what do you do for a living? This stuff look professional. DsmEclipse, I know whatcha mean.

 

[Bill CNC]

devino,

Thank you for the kind words.

I am a Prototype/Model Maker by profession.

Bill

 

[fowler]

that is a very profesional job
assuming u can weld (im sure exalently)
this is going to be one very nice looking machine