 |
10-07-2019, 09:13 PM
|
#1
|
Bus Geek
Join Date: Dec 2017
Location: Dawsonville, Ga.
Posts: 10,482
Year: 1999
Coachwork: Genesis
Chassis: International
Engine: DT466/3060
Rated Cap: 77
|
Hat and C Channel
On a roof raise what thickness metal should be used for the "C" channel insert?
My hat channels are 16g. How much over lap should the "C" channel have?
CB, did I see you say "C" in 18g?
|
|
|
10-07-2019, 10:06 PM
|
#2
|
Bus Geek
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 23,830
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
|
Quote:
Originally Posted by o1marc
On a roof raise what thickness metal should be used for the "C" channel insert?
My hat channels are 16g. How much over lap should the "C" channel have?
CB, did I see you say "C" in 18g?
|
14ga.
|
|
|
10-07-2019, 10:14 PM
|
#3
|
Skoolie
Join Date: Jul 2018
Location: Olathe, Kansas
Posts: 220
Year: 1990
Coachwork: Crown
Chassis: Supercoach
Engine: 6-71TA
Rated Cap: 90
|
Seems thin compared to a Crown but then again everything else seems thin.
|
|
|
10-07-2019, 10:23 PM
|
#4
|
Bus Geek
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 23,830
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
|
Quote:
Originally Posted by GWRider
Seems thin compared to a Crown but then again everything else seems thin.
|
I don't see the point of building the ribbing out of steel thicker than 14 ga.
What's your crown made of?
Maybe that's why they need class 8 running gear?
|
|
|
10-07-2019, 10:27 PM
|
#5
|
Bus Geek
Join Date: Dec 2017
Location: Dawsonville, Ga.
Posts: 10,482
Year: 1999
Coachwork: Genesis
Chassis: International
Engine: DT466/3060
Rated Cap: 77
|
Quote:
Originally Posted by EastCoastCB
I don't see the point of building the ribbing out of steel thicker than 14 ga.
What's your crown made of?
Maybe that's why they need class 8 running gear?
|
Don't the coaches have fewer ribs? So they make up for it in thickness of the rib. Just guessing. 
How much overlap is needed and does it change on the height of the raise, I wouldn't think so?
|
|
|
10-08-2019, 04:31 AM
|
#6
|
Bus Geek
Join Date: Sep 2015
Posts: 3,860
Year: 2002
Coachwork: Thomas Built Bus
Chassis: Freightliner FS65
Engine: Caterpillar 3126E Diesel
Rated Cap: 71 Passenger- 30,000 lbs.
|
It would seem to me that you need enough overlap to secure the ribs to the extension pieces. You *could* butt-end weld the pieces, with the strength of the weld being the weak point. Not suggesting this at all. It also depends on the fastening method used. Bolting the pieces together may require more overlap to get enough strength to bond the pieces in comparison to welding. You would have to make the engineering calculations if you want to be sure.
|
|
|
10-08-2019, 06:51 AM
|
#7
|
Skoolie
Join Date: May 2019
Location: Fresnope, CA
Posts: 154
|
I'd use square tubing, instead of channel. Overlap doesn't need to be much longer than the width of what you're welding. You want a little more than 100% of the sheer value of the stock material. If the outside surface of the hat channel (across the flange, around the back of the "C" part, and across the other flange) is 4 inches, a couple of 2" flare bevel welds along the open side, and one across the back of the C on the other side will be plenty. Or go with a little more overlap, and eliminate the weld across the back.
__________________
"Reality is that which, when you stop believing in it, doesn't go away" - Phillip K. Dick
|
|
|
10-08-2019, 07:55 AM
|
#8
|
Skoolie
Join Date: Aug 2019
Location: Central missouri
Posts: 128
Chassis: 2000 Int Amtran
Engine: DT466HT
Rated Cap: 84
|
Some of us need pictures. lol
|
|
|
10-08-2019, 08:16 AM
|
#9
|
Bus Geek
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 23,830
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
|
Quote:
Originally Posted by JustKip
I'd use square tubing, instead of channel. Overlap doesn't need to be much longer than the width of what you're welding. You want a little more than 100% of the sheer value of the stock material. If the outside surface of the hat channel (across the flange, around the back of the "C" part, and across the other flange) is 4 inches, a couple of 2" flare bevel welds along the open side, and one across the back of the C on the other side will be plenty. Or go with a little more overlap, and eliminate the weld across the back.
|
There isn't square tubing to fit a good many buses.
|
|
|
10-08-2019, 10:19 AM
|
#10
|
Bus Crazy
Join Date: Feb 2012
Location: Salt Lake City Utah
Posts: 1,635
Year: 2000
Chassis: Blue Bird
Engine: ISC 8.3
|
I did my raise by removing the rivets that secured the hat channels to the chair rail. I secured the new hat channel material to the chair rail where the original stuff had been, and I sized the overlap between the extension and the original to be the same height as the chair rail itself - something like 10 inches?. Lacking training in mechanical engineering, it made sense that if those original hat channels were secured to chair rail with so many inches of overlap then I could secure them to hat channel extensions with the same amount of overlap and same quantity and placement of rivets.
|
|
|
10-08-2019, 10:30 AM
|
#11
|
Bus Geek
Join Date: May 2016
Location: Eastern WA
Posts: 6,404
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
|
Quote:
Originally Posted by o1marc
Don't the coaches have fewer ribs? So they make up for it in thickness of the rib. Just guessing. 
How much overlap is needed and does it change on the height of the raise, I wouldn't think so?
|
I can't speak to MCI or Prevost but me Eagle was built very different from our school buses.
There are no frame rails or hat channel.
With the skin off it looked kind of like a spider web of square tube.
We used similarly sized square tube to raise the roof.
On my Bluebird we used C channel formed from 1/8" material and overlapped 10" top and bottom. A little overkill but I have some peace of mind with the structure.
|
|
|
10-08-2019, 10:43 AM
|
#12
|
Bus Geek
Join Date: Sep 2014
Location: Eustis FLORIDA
Posts: 23,830
Year: 1999
Coachwork: Thomas
Chassis: Freighliner FS65
Engine: Cat 3126
Rated Cap: 15
|
Quote:
Originally Posted by PNW_Steve
I can't speak to MCI or Prevost but me Eagle was built very different from our school buses.
There are no frame rails or hat channel.
With the skin off it looked kind of like a spider web of square tube.
We used similarly sized square tube to raise the roof.
On my Bluebird we used C channel formed from 1/8" material and overlapped 10" top and bottom. A little overkill but I have some peace of mind with the structure.
|
Man, Steve- we ended up doing virtually the same roof raise! 
I also had 10" overlap each side.
|
|
|
10-08-2019, 11:03 AM
|
#13
|
Bus Geek
Join Date: May 2016
Location: Eastern WA
Posts: 6,404
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
|
Quote:
Originally Posted by EastCoastCB
Man, Steve- we ended up doing virtually the same roof raise! 
I also had 10" overlap each side.
|
Great minds think alike
|
|
|
10-11-2019, 12:03 AM
|
#14
|
Skoolie
Join Date: Jul 2018
Location: Olathe, Kansas
Posts: 220
Year: 1990
Coachwork: Crown
Chassis: Supercoach
Engine: 6-71TA
Rated Cap: 90
|
Quote:
Originally Posted by EastCoastCB
I don't see the point of building the ribbing out of steel thicker than 14 ga.
What's your crown made of?
Maybe that's why they need class 8 running gear?
|
Seems a tad thicker than 1/8 (10 or 11 ga.).
|
|
|
 |
Thread Tools |
|
Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
» Recent Threads |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|