Machining a Go Cart Wheel Hub
 

I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

Machining a Go Cart Wheel Hub
 

Jeremy Samuels writes:

Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs.

Why not use the HF wheels? For example,

http://www.harborfreight.com/cpi/cta...emnumber=40729
http://www.harborfreight.com/cpi/cta...emnumber=30900

etc.

Machining a Go Cart Wheel Hub
 

Go ahead and make the wheels. If they are too wobbly, paint the cart up
and sell it to some circus clowns for a funny car.
Seriously, with that little equipment and expertise, stick with stock
wheels. Try haunting some wrecking yards for parts.
Bugs

Machining a Go Cart Wheel Hub
 

On 5 May 2006 19:52:52 -0700, "Jeremy Samuels"
wrote:

I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

Forget about aluminum with the welder you have.

You'll want a lot better than 20 thou tolerance on a bearing housing.
You should be able to hold 1 thou with your minilathe over a short
distance like the depth of a bearing. Just take it slow, don't get in
a hurry, measure often, take more than one pass at a given setting
when boring because the bar (and the small lathe) will flex a little
until it's only skinning a thou or less.

Machining a Go Cart Wheel Hub
 

Don Foreman wrote:
On 5 May 2006 19:52:52 -0700, "Jeremy Samuels"
wrote:

I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

Forget about aluminum with the welder you have.

You'll want a lot better than 20 thou tolerance on a bearing housing.
You should be able to hold 1 thou with your minilathe over a short
distance like the depth of a bearing. Just take it slow, don't get in
a hurry, measure often, take more than one pass at a given setting
when boring because the bar (and the small lathe) will flex a little
until it's only skinning a thou or less.

I've welded aluminum before, 6XXX extrusions. It was difficult, but
not impossible. A spool gun would really help, all the problems were
wire feed related.

Turning the hub, I could probably get close to 1 thou accuracy.
Drilling the bolt pattern is where my inaccuracy will be. I expect it
to be 20 or more thou off. This is for a live axle, so no bearing, but
a keyway or a few strong set screws.

Machining a Go Cart Wheel Hub
 

On 6 May 2006 09:54:32 -0700, "Jeremy Samuels"
wrote:


Don Foreman wrote:
On 5 May 2006 19:52:52 -0700, "Jeremy Samuels"
wrote:

I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

Forget about aluminum with the welder you have.

You'll want a lot better than 20 thou tolerance on a bearing housing.
You should be able to hold 1 thou with your minilathe over a short
distance like the depth of a bearing. Just take it slow, don't get in
a hurry, measure often, take more than one pass at a given setting
when boring because the bar (and the small lathe) will flex a little
until it's only skinning a thou or less.

I've welded aluminum before, 6XXX extrusions. It was difficult, but
not impossible. A spool gun would really help, all the problems were
wire feed related.

Turning the hub, I could probably get close to 1 thou accuracy.
Drilling the bolt pattern is where my inaccuracy will be. I expect it
to be 20 or more thou off. This is for a live axle, so no bearing, but
a keyway or a few strong set screws.
With a careful layout you should be able to get within .005" That's
you, not someone else with more experience. I see you have welded
aluminum before with your welder. Did you test your welds? If so, how?
Did you pre-heat the aluminum? Did you notice how soft it was after
welding? Remember, just because a weld looks good doesn't mean it is.
I've seen plenty of "good" welds separate at the weld/partent metal
interface. I personally would not use a welded aluminum hub for this,
unless it was heat treated after welding because the aluminum is so
soft after welding.
ERS

Machining a Go Cart Wheel Hub
 

Jeremy Samuels wrote:
I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

$20?!! Have you priced out what material costs will be to this
yourself? I seriously doubt you can get to less than half, so is your
time worth $10(per). And that assumes that you get it right the first
time.

I realize you are a poor student, but for a potential $20 savings for
probably at least a day of work, I could find other places to employ
some "sweat equity". There is a pretty high chance of making some
scrap or borderline acceptable part here.

JW

Machining a Go Cart Wheel Hub
 

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

$20?!! Have you priced out what material costs will be to this
yourself? I seriously doubt you can get to less than half, so is your
time worth $10(per). And that assumes that you get it right the first
time.

I realize you are a poor student, but for a potential $20 savings for
probably at least a day of work, I could find other places to employ
some "sweat equity". There is a pretty high chance of making some
scrap or borderline acceptable part here.

JW

Here is Option B:

http://www.northerntool.com/webapp/w...70_52526_52526

JW

Machining a Go Cart Wheel Hub
 

jw wrote:
Jeremy Samuels wrote:
I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9

$20?!! Have you priced out what material costs will be to this
yourself? I seriously doubt you can get to less than half, so is your
time worth $10(per). And that assumes that you get it right the first
time.

I realize you are a poor student, but for a potential $20 savings for
probably at least a day of work, I could find other places to employ
some "sweat equity". There is a pretty high chance of making some
scrap or borderline acceptable part here.

Jeez, give the kid a break! He has some tools, he probably has access
to scrap material for free, and he has time!
Note the "rec." in the newsgroup title. This is recreational, and
doesn't need to be cost-justified.
Sometimes we want to make things because we can, for the pleasure of
doing so.

Machining a Go Cart Wheel Hub
 

Jeez, give the kid a break! He has some tools, he probably has access
to scrap material for free, and he has time!
Note the "rec." in the newsgroup title. This is recreational, and
doesn't need to be cost-justified.
Sometimes we want to make things because we can, for the pleasure of
doing so.

I totally understand that. Just asking him to think about what is
going into this. He implied money was a big deal, sometimes making it
yourself isn't the cheapest solution(even with "free" labor).

I'm all for making things, just because you can. Done it myself many
times. But he's trying to make a go kart. Not screw around trying to
make an adequate wheel hub to get it going.

There are a lot of other places on a go kart I would choose to spend
that much effort DIYing than on machining hubs. IMHO.

JW

Machining a Go Cart Wheel Hub
 

Jeremy Samuels wrote:

I'm working on a go cart as a school project with a friend. Our budget
is extremely limited, so we're leaning towards machining our own wheel
hubs. I have a HF minilathe, 1/2" drill press, and a 120v lincoln mig
with c25 and straight argon, so welding aluminum is possible. I'm
wondering what kind of accuracies would be required. Bolts will be at
a 4" circle, tire diameter of 6-8" at a speed of up to 25 mph, I'm
calculating 120 rpm (is that right?). Although this is kind of low,
I'm affraid the heavy radial loads may damage the bearings, especially
with no suspension. I'm confident I can hold 20 thou tolerances with
the setup I have now, but is there anything else I should consider?
I'm using the stock three jaw chuck, with HSS. I have a few boring
bars for the bearing. I don't have a rotary head or cross slide vise,
but have a wiggler.

An example can be found at
http://www.mfgsupply.com/m/c/53-681.html?id=XGPPnfW9



Jeremy -

you might want to check your math on the rotational speed required for
an 8" wheel to go 25 mph.

Doesn't matter for the question at hand, but if you use 120 rpm as a
target when you figure the gears or chain sprockets you'll be
disappointed with the result...

Carla

Machining a Go Cart Wheel Hub
 

you might want to check your math on the rotational speed required for
an 8" wheel to go 25 mph.

Doesn't matter for the question at hand, but if you use 120 rpm as a
target when you figure the gears or chain sprockets you'll be
disappointed with the result...

Carla

Good catch. I thought that rpm seemed really low for 25mph. :)

JW