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 Post subject: Collins vs Book Fame
PostPosted: October 22, 2018, 6:37 pm 
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Joined: May 27, 2013, 6:15 pm
Posts: 5
Getting my frame design nailed down and would like to hear about the pro's and con's of the Collins vs Book frame, specifically the design of the front suspension area (a-arm attachment points). In my inexperienced view the Collins front frame looks easier to build, and perhaps a little easier to build in sections (see my thread "modular frame" ). I should note that the frame would be built with standard "Book" dimensions. I tried to search for more information on the Collins frame but didn't find much.

http://www.locostusa.com/files/Collins.pdf

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 Post subject: Re: Collins vs Book Fame
PostPosted: October 23, 2018, 7:49 am 
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Joined: September 22, 2005, 8:12 am
Posts: 1506
Location: 4AGE in S.E. Michigan
The Collins designed front frame section and suspension bracket attachment would be easier to fab. The Book design would be structurally superior in both areas. It's boils down to what is more important to you.
Only 10,000 more decisions needed to complete the build :ack:
DaveW


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 Post subject: Re: Collins vs Book Fame
PostPosted: October 23, 2018, 12:56 pm 
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Joined: May 27, 2013, 6:15 pm
Posts: 5
Well that brings up a point i hadn't considered. I was mainly curious about the design impact on the suspension and geometry of the a- arms.
Is the book frame structurally superior because the F1/2 tubes run right to the front of the frame rather than to the point circled in the pics below (creating a "hinge" point in the Collins frame):
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Cheers


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 Post subject: Re: Collins vs Book Fame
PostPosted: October 23, 2018, 11:23 pm 
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Joined: December 30, 2007, 1:21 am
Posts: 548
Location: North Van., BC
davew wrote:
Only 10,000 more decisions needed to complete the build :ack:
DaveW


That wouldn't be bad Dave. Some folks make 10,000 decisions just to get started. At least 1,000 for the build table alone. :mrgreen:

Ron

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They say a journey of a thousand miles begins with a single step. By the time you finish the car it'll feel like you've done it on your knees.


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 Post subject: Re: Collins vs Book Fame
PostPosted: October 24, 2018, 7:50 am 
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Joined: September 22, 2005, 8:12 am
Posts: 1506
Location: 4AGE in S.E. Michigan
The Collins frame front lower control arm attachment is cantilevered off the front structure without any triangulation. You will increase the strength some what, by adding the steering bracket if the designed spans the width of the lower boxed structure. Since YOU control the design and fabrication you could add triangulation in that area plus fab additional support for the front lower control arm bracket if going with the Collins design. Because the lower control arm typically see 60% of the impact and braking loads you should really reinforce that area. With either designs you should tie the rear lower control arm bracket to both lower inboard side rail tubes, i.e. in the book design, tubes F1 and G1 & F2 and G2.
Search for aussie frame mod's, for additional front triangulation in the engine bay area. If you know how you will be routing the exhaust in advance of your frame build, then consider additional engine bay side triangulation, which is an excellent way to increase torsional stiffness. The odds are low but if you are not [that's a big if] obstructed and can triangulate from the top of the fire wall down to the engine mount area or R/L/C/A bracket you can easily increase torsional stiffness in the engine bay by another 20%.
DaveW


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 Post subject: Re: Collins vs Book Fame
PostPosted: October 28, 2018, 5:04 am 
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Joined: January 9, 2011, 2:50 am
Posts: 5
Location: Adelaide Australia
G'Day Guys,
The "Book" front end is actually quite easy to build without making all the compound angles on the end of the upright tubes. I've built a few now and I do the front "L" tubes on a piece of MDF/Chipboard with the tube positions drawn on it and build it flat on the board so you only need to cut one angle on the tubes.
The trick is laying the board on the table with the lower end set up at the 15 Deg the L Assy lays back in the frame. I cut a circle out of each side of the board so I can get a square to lay up against the side of the side tubes. Clamp the top and bottom tubes to the board and lay a side tube up with a square sat against the side of the tube and tack both ends in place. do this for both sides then weld it out. When you view the assy on the board, the side facing you is the front, and when you stand it up as it would be in the frame the side tubes are parallel to the centreline of the car. The suspension brackets will automatically be aligned correctly when it comes time to put them on.
Hope this makes sense.
Regards,
Mike.
Adelaide Australia.


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