Rear Bumper Design Feedback
 

First off, I want to thank Roy and Jeff for sending me some pics of
Air tank bumpers about a month ago.

Now, I've finally started designing a set for my CJ7. I'm looking for
people to give me feedback on it. Here is a general description. It
will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
better approach angles. It will have an integrated 2 inch receiver
hitch, and will be suppored by the frame and not just the rear cross
member (with the help of some angle brackets). It will also have
places for shackles. And it will be completely sealed so it can
double as an air tank. The Tire carrier is what I am working on now,
and the front bumper design will follow. I've rendered some pics from
the CAD package I'm designing it in. They can be found here

http://www.4x4owners.com/content/view/36/33/

I'm open to all feedback, I don't want to start building and decide I
should have thought of something else.

Thanks in advance.

----------
Tim J
Chassis - 1984 CJ7
Engine - SBC 305
http://www.4x4owners.com

Re: Rear Bumper Design Feedback
 

On Mar 14, 2:25 pm, "Tim J" <timothyljans...@gmail.com> wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305http://www.4x4owners.com

Looks great overall. The receiver does not seem to stick out enough
to put a pin through it though. Wish I had the skills to do something
like this.

Re: Rear Bumper Design Feedback
 

On Mar 14, 2:25 pm, "Tim J" <timothyljans...@gmail.com> wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305http://www.4x4owners.com

Looks great overall. The receiver does not seem to stick out enough
to put a pin through it though. Wish I had the skills to do something
like this.

Re: Rear Bumper Design Feedback
 

On Mar 14, 2:25 pm, "Tim J" <timothyljans...@gmail.com> wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305http://www.4x4owners.com

Looks great overall. The receiver does not seem to stick out enough
to put a pin through it though. Wish I had the skills to do something
like this.

Re: Rear Bumper Design Feedback
 

Looks like good start.

a few comments: 1/4" is way heavier than needed. 3/16" is plenty, 1/8"
is ok depending on what you want to do with it. You need to review how
long to make it: if you do rock crawling, you will want to expose the
entire tire to the rock, ie about 45" long. If you do heavy brush like I
do, the bumper should come to about the center of the tire so that brush
does not get hung up between the tire and the frame, about 57" long. If
it is mostly show and city traffic, any length is fine but longer is
better to protect your ride from the other guys.

You are showing clamping the mounts between the sides of the frame
rails. This does not work on a YJ because the shackle mount is welded
into the frame itself. IIRC, the CJ hangs the shackle mount below the
frame, your drawing may work. Better check carefully that there is no
interferance at full cmpression.

I didn't see any provision for tow hooks, rear lights (fog lamp style
for dealing with stuckiness in the dark!), receiver hitch lock pin
(watch the distance from hitch ball to hole on the ball mount), or
safety chains. You do show shackle mounts but they are in the center of
the tube side, will bow out the first time you get serious about pulling
something (someone) out.

Tim J wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305
> http://www.4x4owners.com
>

Re: Rear Bumper Design Feedback
 

Looks like good start.

a few comments: 1/4" is way heavier than needed. 3/16" is plenty, 1/8"
is ok depending on what you want to do with it. You need to review how
long to make it: if you do rock crawling, you will want to expose the
entire tire to the rock, ie about 45" long. If you do heavy brush like I
do, the bumper should come to about the center of the tire so that brush
does not get hung up between the tire and the frame, about 57" long. If
it is mostly show and city traffic, any length is fine but longer is
better to protect your ride from the other guys.

You are showing clamping the mounts between the sides of the frame
rails. This does not work on a YJ because the shackle mount is welded
into the frame itself. IIRC, the CJ hangs the shackle mount below the
frame, your drawing may work. Better check carefully that there is no
interferance at full cmpression.

I didn't see any provision for tow hooks, rear lights (fog lamp style
for dealing with stuckiness in the dark!), receiver hitch lock pin
(watch the distance from hitch ball to hole on the ball mount), or
safety chains. You do show shackle mounts but they are in the center of
the tube side, will bow out the first time you get serious about pulling
something (someone) out.

Tim J wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305
> http://www.4x4owners.com
>

Re: Rear Bumper Design Feedback
 

Looks like good start.

a few comments: 1/4" is way heavier than needed. 3/16" is plenty, 1/8"
is ok depending on what you want to do with it. You need to review how
long to make it: if you do rock crawling, you will want to expose the
entire tire to the rock, ie about 45" long. If you do heavy brush like I
do, the bumper should come to about the center of the tire so that brush
does not get hung up between the tire and the frame, about 57" long. If
it is mostly show and city traffic, any length is fine but longer is
better to protect your ride from the other guys.

You are showing clamping the mounts between the sides of the frame
rails. This does not work on a YJ because the shackle mount is welded
into the frame itself. IIRC, the CJ hangs the shackle mount below the
frame, your drawing may work. Better check carefully that there is no
interferance at full cmpression.

I didn't see any provision for tow hooks, rear lights (fog lamp style
for dealing with stuckiness in the dark!), receiver hitch lock pin
(watch the distance from hitch ball to hole on the ball mount), or
safety chains. You do show shackle mounts but they are in the center of
the tube side, will bow out the first time you get serious about pulling
something (someone) out.

Tim J wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305
> http://www.4x4owners.com
>

Re: Rear Bumper Design Feedback
 

Nice.

I would recommend crush sleeves in the back frame between the angle
irons. These are easy to make. You drill the 3/8" hole in one side for
the bolt to run through and on the other side you drill a hole to fit a
3/8" ID piece of pipe the width of the frame minus one layer of frame.
The pipe then slides and butt to the 3/8" hole on the other side to
cross the frame and fits flush on the larger hole side. Your bolt will
then not crush the frame.

It is amazing the stress that can happen in an extraction. I bent my
Warn HS9000i's mounting plate the first time I used it. I am glad the
frame had crush sleeves that came with the kit....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Tim J wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305
> http://www.4x4owners.com
>

Re: Rear Bumper Design Feedback
 

Nice.

I would recommend crush sleeves in the back frame between the angle
irons. These are easy to make. You drill the 3/8" hole in one side for
the bolt to run through and on the other side you drill a hole to fit a
3/8" ID piece of pipe the width of the frame minus one layer of frame.
The pipe then slides and butt to the 3/8" hole on the other side to
cross the frame and fits flush on the larger hole side. Your bolt will
then not crush the frame.

It is amazing the stress that can happen in an extraction. I bent my
Warn HS9000i's mounting plate the first time I used it. I am glad the
frame had crush sleeves that came with the kit....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Tim J wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305
> http://www.4x4owners.com
>

Re: Rear Bumper Design Feedback
 

Nice.

I would recommend crush sleeves in the back frame between the angle
irons. These are easy to make. You drill the 3/8" hole in one side for
the bolt to run through and on the other side you drill a hole to fit a
3/8" ID piece of pipe the width of the frame minus one layer of frame.
The pipe then slides and butt to the 3/8" hole on the other side to
cross the frame and fits flush on the larger hole side. Your bolt will
then not crush the frame.

It is amazing the stress that can happen in an extraction. I bent my
Warn HS9000i's mounting plate the first time I used it. I am glad the
frame had crush sleeves that came with the kit....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)


Tim J wrote:
> First off, I want to thank Roy and Jeff for sending me some pics of
> Air tank bumpers about a month ago.
>
> Now, I've finally started designing a set for my CJ7. I'm looking for
> people to give me feedback on it. Here is a general description. It
> will be made from 2"x5"x1/4" tube stock. The ends will be tapered for
> better approach angles. It will have an integrated 2 inch receiver
> hitch, and will be suppored by the frame and not just the rear cross
> member (with the help of some angle brackets). It will also have
> places for shackles. And it will be completely sealed so it can
> double as an air tank. The Tire carrier is what I am working on now,
> and the front bumper design will follow. I've rendered some pics from
> the CAD package I'm designing it in. They can be found here
>
> http://www.4x4owners.com/content/view/36/33/
>
> I'm open to all feedback, I don't want to start building and decide I
> should have thought of something else.
>
> Thanks in advance.
>
> ----------
> Tim J
> Chassis - 1984 CJ7
> Engine - SBC 305
> http://www.4x4owners.com
>