QUOTE now where have I seen that before? wink.gif
"I stand on the shoulders of giants"
-and no, that's not original with me either!
EM
"I stand on the shoulders of giants"
-and no, that's not original with me either!
EM
Building a Pre-Add BRM
The combination of an apparent high level of interest in Mac Pinches Pre-Add bdies as decribed in "News" and the recent arrival of some of Mac's new laser cut chassis has prompted me to start another project along side the W154/Patto chassis that is ongoing.
Thinking that there might be some interest in this project, I am going to document it in photos and (hopefully) brief text as it progress.
These will be a series of "real time" progress reports, not a "how to" since what I describe in one post may well be reversed in the next when I discover that it didn't work! I'll try to keep a rough log of time and cost.
The bits and pieces:
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In no particular order: the body molding, driver, vac-formed screen and metal castings for the steering wheel, exhausts and filler cap (all part of the body kit) There are actually two chassis in the picture - on the lower right the laser cut chassis as supplied and spread about the middle, the parts after cutting and removal of the webs. The rear axle carriers/rear motor mount are "stuck" together. The fit of the parts is so good that the assembly is stable without soldering! Also in the picture is a guide and guide shaft bearing. One of the first things that I do with any commercial chassis is to try and figure out what guide shaft fits the hole. This is of particular interest for laser cut steel chassis because my experience is that these holes can oly be enlarged with some difficulty, the steel being very hard. In this case, the TSRF guide made for conversion of plastic chassis is a perfect fit and, on preliminary examination, to be short enough so that it will not extend beyond the front of the car (important for some rules)
Now let's do the numbers: A quick Google search yielded:
http://8w.forix.com/brmp15.html
LOA: 158"
Width 56"
Height 35"
WB 98"
Wheels and tires: 5.25 X 18 front, 7.00 X 17 rear
If I believe my digital caliper, the wheelbase is spot on and the length is very close (perhaps 0.10" too short, but, the body that Mac has modeled differs from the one pictured on the site so I'm going to call it perfect!
A listing of tire dimensions for Dunlop Vintage Series tires yields:
7.00 X 17 30.2" diameter
5.50 X 18 30.1" and 5.00 X 19 29.6" so I'm calling 5.25 X 18 as 29.7"
This translates into 0.94" rear tires and , rounded to /100s, the same at the front.
Quick dimension check: The distace from the center of the rear axle carrier to the bottom of the chassis is about 0.288" If we subtract that from the radius of the proposed rear tire, 0.47", we are left with 0.18", plenty of room to add a weight pan and still meet a 0.125" ground clearance rule.
Second check - height is listed @ 35" or 1.1" in 1/32 scale. Knowing the axle height we can then check the body to see where the axle would be to give us that height in the finished car - and it turns out to be exacltly where Mac has placed the top of the rear axle slots!
Little worry (postponed until the initial chassis assembly is done and a motor fitted) - the fit between the top of the motor and the dash is the limiting factor for positioning the body on the chassis and, at first glance, it is a problem. The decision will be: can enough be ground off the bottom of the dash to accomodate the motor or will the dimensions dictate a front motor placement (and, in the latter case, isn't it nice that the chassis kit includes twoadditional motor mounts!)
An issue which has arisen long before its time: decoration: I am not really enamored of the peculiar diseased liver green that was chosen for these cars! (I recognize that there may have been budget constraints but did they really have to use paint left over from the redecoration of the railway station loos?) Any suggestions as to alternate correct liveries will be appreciated. I reserve the right to assign the car to Ecurie Martini and since this organization (long predating the red, white and blue "Martini" sponsorships) is a Belgian/American consortium, I'll paint it yellow!
Time so far, hands on and on the net, about 2 hours - parts @ current exchange, about $50
Next steps: chassis assembly, motor, axles & gears
EM
Thinking that there might be some interest in this project, I am going to document it in photos and (hopefully) brief text as it progress.
These will be a series of "real time" progress reports, not a "how to" since what I describe in one post may well be reversed in the next when I discover that it didn't work! I'll try to keep a rough log of time and cost.
The bits and pieces:
In no particular order: the body molding, driver, vac-formed screen and metal castings for the steering wheel, exhausts and filler cap (all part of the body kit) There are actually two chassis in the picture - on the lower right the laser cut chassis as supplied and spread about the middle, the parts after cutting and removal of the webs. The rear axle carriers/rear motor mount are "stuck" together. The fit of the parts is so good that the assembly is stable without soldering! Also in the picture is a guide and guide shaft bearing. One of the first things that I do with any commercial chassis is to try and figure out what guide shaft fits the hole. This is of particular interest for laser cut steel chassis because my experience is that these holes can oly be enlarged with some difficulty, the steel being very hard. In this case, the TSRF guide made for conversion of plastic chassis is a perfect fit and, on preliminary examination, to be short enough so that it will not extend beyond the front of the car (important for some rules)
Now let's do the numbers: A quick Google search yielded:
http://8w.forix.com/brmp15.html
LOA: 158"
Width 56"
Height 35"
WB 98"
Wheels and tires: 5.25 X 18 front, 7.00 X 17 rear
If I believe my digital caliper, the wheelbase is spot on and the length is very close (perhaps 0.10" too short, but, the body that Mac has modeled differs from the one pictured on the site so I'm going to call it perfect!
A listing of tire dimensions for Dunlop Vintage Series tires yields:
7.00 X 17 30.2" diameter
5.50 X 18 30.1" and 5.00 X 19 29.6" so I'm calling 5.25 X 18 as 29.7"
This translates into 0.94" rear tires and , rounded to /100s, the same at the front.
Quick dimension check: The distace from the center of the rear axle carrier to the bottom of the chassis is about 0.288" If we subtract that from the radius of the proposed rear tire, 0.47", we are left with 0.18", plenty of room to add a weight pan and still meet a 0.125" ground clearance rule.
Second check - height is listed @ 35" or 1.1" in 1/32 scale. Knowing the axle height we can then check the body to see where the axle would be to give us that height in the finished car - and it turns out to be exacltly where Mac has placed the top of the rear axle slots!
Little worry (postponed until the initial chassis assembly is done and a motor fitted) - the fit between the top of the motor and the dash is the limiting factor for positioning the body on the chassis and, at first glance, it is a problem. The decision will be: can enough be ground off the bottom of the dash to accomodate the motor or will the dimensions dictate a front motor placement (and, in the latter case, isn't it nice that the chassis kit includes twoadditional motor mounts!)
An issue which has arisen long before its time: decoration: I am not really enamored of the peculiar diseased liver green that was chosen for these cars! (I recognize that there may have been budget constraints but did they really have to use paint left over from the redecoration of the railway station loos?) Any suggestions as to alternate correct liveries will be appreciated. I reserve the right to assign the car to Ecurie Martini and since this organization (long predating the red, white and blue "Martini" sponsorships) is a Belgian/American consortium, I'll paint it yellow!
Time so far, hands on and on the net, about 2 hours - parts @ current exchange, about $50
Next steps: chassis assembly, motor, axles & gears
EM
81 - 82 of 82 Posts
G
What a wonderful BRM, EM.
RR
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RR
81 - 82 of 82 Posts
