Wheelbarrow hot rod

[Allracing]

Time to start on the frame The solution was in the cards; it had to be based on two rectangle section frame rails like a real hot rod. So I went and got some 25x50x3mm (1x2’’, 1/8’’ wall thickness). Cut the 2 rails a little longer than needed:

I wanted to contour the frame to meet a few criterias:

- Wide in the back to put the axle bearings close to the rear wheels

- Frame rails should follow the edge of the ‘’body’’ i.e. wheelbarrow tray

- Narrow in the front to get the split wishbones swung in and away from the front wheels. And to bring forward the looks of the I beam axle.

So I started cutting up my perfectly good rails!

And finished off with a mock up:

Rails are too long front and back, will cut to length and get some crossmembers in there as the next step

 

[ezcome-ezgo]

Nice!!

 

[Allracing]

Put in some more work on the frame. I wanted a round x-member in the front with a spring perch, inspired by t-bucket rods. It meant more work than a rectangular one would have but what the ****. I cut the front of the rails to length and prepped them for the x-member (made from some round tubing):

Welded in the x-member:

Still struggling to make pretty youtube quality welds but I am patient and learning a little at the time


Then made a spring perch from the same rectangular tubing that the frame rails were made of:

Tacked it it:

Progress in the frame so far (rear crossmember is a dummy):

 

[Kartorbust]

She's coming together nicely. Can't wait to see the finished product!

 

[Allracing]

I wanted to change things up a little bit after doing alot of weldig so decided to start working on the front spindles. Started out with a nice chunk of 6061 aluminium:

Cut 2 workpieces which I took to the lathe for further refinement. The drawings that I am working from are in my head only , which usually is not a good idea. But this project is meant to be freestyle and feelgood so let’s get going. Time will show how this works out:

These bad boys are going to need alot more work. More to come

 

[Allracing]

Moved the spindles over to my Bridgeport mill and continued the work there. Started by flattening top and bottom on each spindle:

Then cut the slot within which the ends of the I-beam axle will sit:

Next up will be to bore the king pin holes.




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[Kartorbust]

Can't wait to see what they look like when they are done

 

[Desertduler]

Nice work!

 

[Allracing]

Got the kingpin holes bored. Fiddly work as I am going to line the holes with bronze bushings, meaning I need to bore the holes to really tight tolerances. The bushings like an interference fit and upon control measurent they all come in at 18.02-18.03mm. I aimed to bore the holes as close to 18.00mm as I could, for a 0.02-0.03mm press fit. Ended at like 17.97-17.99 for the 4 holes. Probably a tad tight but then again the spindles are aluminium so should be forgiving enough.

 

[ezcome-ezgo]

This is good stuff.

 

[Allracing]

More spindle action - time to make the stub axles. Used 25.4mm (1’’) prehardened 4140 round stock for these. This is a nice, strong material which machines well too, as long as heat is controlled. Wheel bearings are 25mm ID so not much to remove from the OD of the workpiece. Here I’m done and parting off the first one:

Drilled and tapped for a 10mm bolt on the outboard side of the axle:

Drilled the rest of the axle with a 12mm drill to remove some mass. Done! They are ready to be pressed into the spindles:

 

[Allracing]

Time to mate the stub axles to the spindle bodies. The king pin inclination on the I-beam axle is 7.5deg so I planned to install the stub axles at 7deg for 0.5deg negative camber on the wheels. Started by flattening the sides of the spindle bodies to be able to clamp them in the vice the way I wanted to:

I then set them in the vice at 7deg:

And flattened the surface against which the wheel bearing will sit:

Then bored the hole for the stub axle. Got 0.06-0.07 interference om both, a pretty tight fit:

I set up the parts in the press to install the stub axles into the spindle bodies:

I heated the bodies with a heat gun and attempted to press the parts together. Nogo. Tried a couple times but couldn’t enter the stub axle straight into the body. Too much give in the setup apparently. So I tried with more heat and at somewhere well above 100degC/212F the axle dropped right in. Done:

 

[ezcome-ezgo]

This is awesome.

 

[qtband]

You're doing the things that most of us can only dream of doing. Keep it up!

 

[Allracing]

Thank you for the kind words guys

---------- Post added at 09:37 PM ---------- Previous post was at 09:28 PM ----------

Figured I’d pin the stub axles to the spindle bodies to discourage them from coming out at any point in time. Drilled from the underside:

Tapped for a 6mm (1/4’’) screw:

Countersunk, and installed a screw:

Still some work left on these bad boys. Need to install the bronze bushings and bore them to the correct ID, drill and tap for the steering arms and install grease nipples for the bushings. Phew, quite a bit of time invested in these. It has been alot of fun though

 

[Allracing]

Continued the spindle marathon. The amount of work with these make me 2nd guess the project. However, there is some comfort in that this is probably the most complex and time consuming part of this go-kart.

Anyway, drilled and tapped holes for the steering arms. The will be one upper arm connected to a steering box of some sort + 2 lower arms connected to eachother by a tie-rod. I don’t know which side will have the upper arm, so drilled and tapped both:

Bored the I-beam axle to accomodate the 12mm (just shy of 1/2’’) king pin. Tight slip fit:

Time to install bushings in the spindles. Had to heat here due to slightly tighter than ideal tolerances, which made the bushings bleed some oil (they are Oillite bushings which mean they are 60% metal and 40% oil). Nevermind. They turned out fine:

Last piece of the puzzle was finding a way to lock the king pin in the axle. I decided to do it the way Ford did it on their I beam axles. First, I needed some meat in the area close to the axle end. Welded up the axle at these points:

Machined the same areas flat and drilled a 6mm (~1/4’’) all the way through then an 8mm (~5/16’’) almost through (left 3mm (~1/8’’) of 6mm (~1/4’’) hole).

Will clean up the edges of the new flat by grinding, at a later stage.

Then made a pair of locking screws to fit in the new holes in the axle. Made these out of some old bolts:

Ground flats on the king pins to accomodate the locking screws. Had to be ground as the king pins are hardened and can’t be touched with cutting tools:

Finally, time to install the spindles onto the axle:

I am very pleased with the restult. The spindles require little effort to turn, yet have no play at all. Should make for a tight ride.

It remains to install grease nipples and perhaps to slim the with of the spindles some more. But that will be another day.

Next up: hang the axle on the frame

 

[ezcome-ezgo]

Thank you for including us in this adventure. Looking forward to the next installment.

 

[Allracing]

Need to finish up my split wishbone wannabies. I’ll hang them with tie-rod ends on the frame side. Bought these bad boys for a decent price on eBay.

They are 10mm (~3/8’’) with a 1.25mm pitch. This is not the usual metric pitch which would be 1.5mm. A semi fine pitch on other words. So had to buy taps as well, one standard and one LH. Luckily those can be had cheap too...

Anyway, threaded the frame end of the ‘bones and installed the tie rod ends:

On the axle side, there is a bit more work. I started machining some ends to fit the axle. I plan to weld these to the fat side of the wishbones. Squared off 2 workpieces:

Rounded off 1 side on each:

Drilled and reamed them to 8mm (~5/16’’):

Made these out of some 10mm (~3/8’’) bolts. The are turned to just shy of 8mm for a slick fit through the bone ends:

Machined pockets for the I-beam axle:

(Just getting started in this pic, forgot to take any more shots)

Drilled and reamed the I-beam to 8mm:

And pre-installed the pieces:

The ‘bone ends will be massaged a bit more to fit the wishbones.

 

[landuse]

This is such a cool build! Sorry I don't have much to say. I don't think you need our advice though....it looks like you have everything covered

 

[Allracing]

This is such a cool build! Sorry I don't have much to say. I don't think you need our advice though....it looks like you have everything covered

Thank you I wish I had it all covered! It is my first build though and I really don’t. No idea if/how this thing is going to drive and handle when it is finished but only one way to find out I guess