LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently September 27, 2021, 3:27 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 6 posts ] 
Author Message
PostPosted: September 17, 2019, 8:58 pm 
Offline
User avatar

Joined: January 2, 2009, 1:45 pm
Posts: 1303
Location: Halifax, Nova Scotia
I am bolting rubber torsion suspension onto a trailer that I am building and want (need?) to add crush tubes to carry the compression load from the bolts where they penetrate the rectangular tube frame rails. I am planning on using schedule 40 steel pipe for crush tube, but the selection of diameters is rather limited, and I'm reluctant to drill out the length of an undersized tube but otherwise will have a sloppy fit on one end at least. The internal diameter of a 3/8 Sch 40 pipe is something like 0.49 inches, and the ID of the next lower size (1/4 in.) is too small for a 3/8 bolt.

Any suggestions?

_________________
Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601


Top
 Profile  
Reply with quote  
PostPosted: September 17, 2019, 9:34 pm 
Offline

Joined: April 17, 2009, 1:28 am
Posts: 190
Location: San Tan Valley, Arizona
1/4 sched 40 pipe is .364 could very easily be drilled to .375 and then reamed .002 over or use a size "V" (.377") bit to finish.


Top
 Profile  
Reply with quote  
PostPosted: September 17, 2019, 9:53 pm 
Offline
User avatar

Joined: July 17, 2008, 9:11 am
Posts: 5935
Location: West Chicago,IL
I really hadn't thought about it. I would guess that the cross section of the tube should be greater than the cross section of the bolt being used. Buckling must be avoided. I don't think this will be a problem with a relatively close fit of tube vs bolt. Steel tubing (not schedule 40 pipe) can be bought from many different sources in various OD's and wall thicknesses. I've been fortunate to find the right sizes for reinforcing axle slices and trailer axles. I'm sure that a bit of searching for steel tube in various wall thicknesses should get you close.

Are you wanting to use 1/2" hardware? Looking at onlinemetals.com I see .75 OD Cold rolled with .12 wall is available. This gives .51 ID. the cross sections is larger than the 1/2 inch bolt.
https://www.onlinemetals.com/en/buy/tub ... eckbox=on#

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE


Top
 Profile  
Reply with quote  
PostPosted: September 18, 2019, 8:08 am 
Offline
User avatar

Joined: January 2, 2009, 1:45 pm
Posts: 1303
Location: Halifax, Nova Scotia
Thank you. I will do some more homework.

Thee other twist on my application is that I am galvanizing the trailer. Do I fit the crush tube loose and naked, or do I weld it in and galvanize it?

Decisions, decisions. :-)

_________________
Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601


Top
 Profile  
Reply with quote  
PostPosted: September 18, 2019, 8:42 am 
Offline
User avatar

Joined: July 17, 2008, 9:11 am
Posts: 5935
Location: West Chicago,IL
Personally, I would weld the crush tubes in place, then dip the frame. Zinc is very soft and if it gets in the ID, then chasing with an appropriate sized drill should be easy. Much easier than drilling an undersized hole, which is pretty easy itself.

_________________
Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE


Top
 Profile  
Reply with quote  
PostPosted: September 20, 2019, 9:09 pm 
Offline
User avatar

Joined: January 2, 2009, 1:45 pm
Posts: 1303
Location: Halifax, Nova Scotia
Went with 1/4 sched 40 pipe and fitted the first crush tube tonight. I won't weld until I've fitted all eight. Picky work or what, but better safe than doing without.

_________________
Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY