Now that the plan was taking shape I had a good
idea of what I needed to purchase for Project BMP. This is actually a
pretty fun portion of the project, I mean who doesn't like to find presents on the
doorstep? Ok, so maybe the fun wears off when the Visa bill arrives, but at
least you have a pile of shiny parts. I sat down early on and made a
spreadsheet to track the costs and time on this project. First up was
figuring out what I would use from my old crawler. If the parts were
fairly new I just used the receipt price, if they were older I guessed at what
they might be worth now. I really didn't need to assign prices but I just
know when this is done I will be asked how much did it cost (right after the
"how much does it weigh?" question).
Next up is keeping track of what I need. As
I locate parts I usually hyperlink the part to the internet site I am going to
buy it from, makes it easy to find when the time has come to order it. The
column on the left is parts purchased to date (including shipping and taxes).
The first couple rows are blank since I have broken even on the parts car that
the transmission and t-case came from. Tubing and the coilovers are on the
verge of being ordered so I have them in both columns.
To avoid having to drop a lot of money at once on
parts I may not need for weeks I am going to stagger my purchases and bring
stuff in only when I am close to needing it. This will also allow me
to watch for sales to maximize my project dollars. What I haven't shown in
the pictures above is the list of parts I would like to buy if I have money left
over, so there is some incentive to keep costs down.
On to phase 1. Basically I want to
build the base of the buggy and get the drive train mounted to it.
This explains all the drive train parts I have on order. Coming from
is a Ringr transmission adapter, a modified Celica 1970-71 clutch disc (machined
3/8" smaller), a modified Sidekick throwout bearing (the bore is opened up to
fit the Toyota transmission snout) and a Sidekick pilot bearing. From
Marlin Crawler I
ordered a dual case adapter. There is a cheaper alternative to the Marlin
Adapter but after reading about some of the differences there is no way I'd use
the cheaper one especially considering the difference in price is well under
$100 or in my case about $15 due to a sale. To complete the drive train I have a
Sidekick 4x4 bellhousing coming from
Hawk Strictly Suzuki and a pressure plate
from Checker Auto Parts.
Tubing is next up on the to buy list (all but the
1" dia stuff is DOM). I plan on buying it all at once in order to get a
discount. As you can see, steel prices are still pretty
high, roughly double what I paid two years ago. I will also swap out all my
1.38 x .120 wall tubing for 1.50 x .095 wall tubing to save weight and to cut
down on the number of tools I will need (more on that below).
I put the 1.38 x .120 tubing in my design to save
some weight. It was going to be used for bracing in areas not expected to
take rock hits but out of curiosity I played around with the tubing in the
FEA software we have at work. I modeled a 36" long piece of DOM tubing,
constrained it at both ends, then applied a 3000lb load to the middle of it in
one direction. This would simulate a slow roll, a fast roll would easily
multiply that force value. Here is the estimated amount of deflection each material
1.375 OD X .120 Wall = .26in
1.50 OD X .095 Wall = .24in
1.50 OD X .120 Wall = .19in
As you can see there wasn't a huge difference
between any of the materials. Assuming good welds on the ends, the tubing
would most likely dent. Knowing this I am going to replace all the 1 3/8
braces with 1.50 x .095 wall tubing. This will save a little weight and
eliminate the need to buy 1 3/8 hole saws.
Eliminating all the 1 3/8 tubing also
means I only have to buy one of these tools. It's called a Pipemaster,
Trick-Tools.com in a variety of sizes and are designed to make notching
tubes at odd angles much easier. Basically you position the two tubes in
relation to each other, slide the pipemaster over the tube that needs notching
and then slide it down till the metal pins form the shape of the other tube,
this gives you the profile of the required notch. You can then transfer
this profile to the tube that needs to be notched. If this little tool
works good it will save me a lot of time.
The other tool I picked up from
Trick-tools is a pair of these
welding positioners. Hopefully they'll be as valuable as a second set
I have begun the tear down of the old
rig. The first thing I did today was to pull all my tools and spare parts
out to weigh them and then put them away. I ended up pulling out 212lbs of
gear broken down as follows:
Ammo Cans (2)
Ammo Can (1)
Spare Axles (3)
I guessed 200-300lbs so I was in the
ballpark. I am hoping to pare down the spare parts in Project BMP, leaving
more of the heavy stuff at the trailer unless the remoteness of the trail
On the design front I have continued to
refine the chassis design. I went through my model today and changed most
of the dash bar tubing and the cooler rack tubing to 1.00 x .055 wall. I
also eliminated a some redundant braces and changed the roof shape. I
managed to cut about 50lbs of weight off the chassis bringing it down to 460lbs.
Another change was the decision to go
with a set of 16" air shocks instead of purchasing another set of coilovers.
Both economics and the weight savings helped push me in this direction.
From what I have read and heard, the airshocks weigh about 6-8lbs each as
opposed to roughly 42lbs for a single coilover shock with dual coils. That
is a huge weight savings. I have the airshocks slated to go in the rear of
the buggy since that will be the lighter end. This change along with the
chassis refinements puts the estimated Project BMP weight at 2574 lbs, down from
just over 2800lbs. I am really happy with this especially since it
includes a tire upgrade to some 38 x 15.50 MT Baja Claws.
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