LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently July 22, 2019, 8:55 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 127 posts ]  Go to page Previous  1 ... 5, 6, 7, 8, 9  Next
Author Message
PostPosted: May 8, 2019, 8:03 am 
Offline
User avatar

Joined: October 19, 2010, 11:57 am
Posts: 485
Location: Waterloo, WI
Looking great! :cheers:

_________________
-Keith


Top
 Profile  
Reply with quote  
PostPosted: May 18, 2019, 3:28 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
Diff cage is basically done, need to cover up a few tube ends. I must be really bad at fixturing for welding cause it took 3 tries to get the top arm and the lower arm connected with the 2 vertical braces without it moving all over.

I had the diff cage mounted to the engine (12mm bolts just sitting in clearance hole on the engine and the diff mounted to the cage tightly. Then I clamped and tacked the vertical braces in. The first time I swear it moved an 1/8" or more after I finished the welds.

But third time was the charm (well, not charm really, more like f-it close enough!)


Attachments:
diff_cage_02.png
diff_cage_02.png [ 1.35 MiB | Viewed 1252 times ]

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."
Top
 Profile  
Reply with quote  
PostPosted: May 19, 2019, 6:07 am 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 6082
Yeah, I can see how that would move on you while welding. Needs a 4 point jig to hold it.

I suggest using motorcycle type chain adjusters. They are jambed after adjusting so even if the clamp is lost at the bolts, the tension doesn't immediately go away. I think they will be important to have considering your threaded into aluminum. 3/16 strip double hole washer with flanges/boxed edge, 3/8x3 bolts and nuts to jamb and adjust, blind nut plates on the cage.

_________________
MV8

https://www.youtube.com/watch?v=Om3C1Ep ... D3E18BB447


Top
 Profile  
Reply with quote  
PostPosted: May 19, 2019, 3:17 pm 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
Yeah, I was thinking something more than what I've got on there, like a screw stop would be nice.

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."


Top
 Profile  
Reply with quote  
PostPosted: May 20, 2019, 4:31 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
I thought while I was having welding success, I'd try to plug some of the holes in the diff. I'm not sure what the diff case is, I'd guess cast steel, but it worked pretty good. There was a bit of sputtering and smoke and it seemed like I could only weld about 3/8" long until I felt like I should stop and clean it with a brush.

I assume those four ends were open to allow some oil circulation where the screws are sliding when "diffing". I think that would be a good place to put some grease zerks. There are two more holes like these on the other end.

But then there are the two big openings in the middle of it. One is needed for access to remove a central spacer thingie so the whole diff can be dissasembled. The one opposite, I'm not sure, maybe to balance out the needed opening. Not quite sure how I'm going to seal those since the needed one is, well, needed. I guess I could make a bolt on cover for it. The BEC book guy suggest a cooking pot, NOT!


Attachments:
diff_hole_filling_01.png
diff_hole_filling_01.png [ 907.53 KiB | Viewed 1175 times ]
diff_hole_filling_02.png
diff_hole_filling_02.png [ 1.23 MiB | Viewed 1175 times ]

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."
Top
 Profile  
Reply with quote  
PostPosted: May 26, 2019, 1:24 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
Fitted some grease zerks to the diff and made some chain adjuster stops.


Attachments:
diff_cage_03.png
diff_cage_03.png [ 1.25 MiB | Viewed 1054 times ]

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."
Top
 Profile  
Reply with quote  
PostPosted: May 27, 2019, 4:44 am 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 6082
Looks like that'll work too. I was suggesting something like this extra crude drawing.


Attachments:
JOHNSINSKI adjiuster.JPG
JOHNSINSKI adjiuster.JPG [ 128.76 KiB | Viewed 1009 times ]

_________________
MV8

https://www.youtube.com/watch?v=Om3C1Ep ... D3E18BB447
Top
 Profile  
Reply with quote  
PostPosted: June 1, 2019, 12:45 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
Got a quote for my 2 roll hoops. 1 3/4" x .109", 10" CLR. Over $500 for both. Now before I completely blow up, I get it, it's special work and all, but Holy F! That seems a bit steep.

Not that that's off the table, but I'm designing my own bender now (based on various internet research). The problem with buying one is I can't even find 10" CLR dies. Did I just design the roll hoops wrong? 10" CLR seems nice (for a single seater).

The large arc is cast steel. Not sure how I'm gonna do that one! Probably won't.


Attachments:
bender_01.jpg
bender_01.jpg [ 64.88 KiB | Viewed 895 times ]

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."
Top
 Profile  
Reply with quote  
PostPosted: June 1, 2019, 5:23 am 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 6082
With such a large radius, have you considered a roller bender (3 small die type)?

_________________
MV8

https://www.youtube.com/watch?v=Om3C1Ep ... D3E18BB447


Top
 Profile  
Reply with quote  
PostPosted: June 1, 2019, 11:36 am 
Offline
User avatar

Joined: July 17, 2008, 9:11 am
Posts: 5065
Location: West Chicago,IL
What determines your chosen tubing dia , wall thickness and radius?

A lot of us have used Rollcagecomponents.com to make our custom roll bars. That is where I had mine made. And Jack gets his made by him too, at least he used to. I can't say if he has changed suppliers since. They have 1-3/4 x .095 and .120 wall DOM available. I'm not sure what radius tooling he has. You might try giving Jimmy a call to talk about his available options.

_________________
Chuck.

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

Visit my ongoing MGB Rustoration log: over HERE


Top
 Profile  
Reply with quote  
PostPosted: June 1, 2019, 1:48 pm 
Offline
User avatar

Joined: July 29, 2006, 9:10 pm
Posts: 2973
Location: Oregon, usually
rx7locost wrote:
And Jack gets his made by him too, at least he used to.
Yep, I still do. Jimmy's terrific.

_________________
Locost builder and adventurer, and owner/operator of http://www.kineticvehicles.com


Top
 Profile  
Reply with quote  
PostPosted: June 1, 2019, 2:24 pm 
Offline
Mid-Engined Maniac

Joined: April 23, 2006, 8:26 pm
Posts: 5963
Location: SoCal
Unless it's really necessary, a chassis doesn't require a fixed bend radius. The Midlana plans only fix the end points (and overall width and height), giving builders the freedom to use any bend radius within reason.

_________________
Midlana book: Build this mid-engine Locost!, http://www.midlana.com/
Kimini book: Designing mid-engine cars using FWD drivetrains, http://www.kimini.com/book_info/


Top
 Profile  
Reply with quote  
PostPosted: June 2, 2019, 2:06 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
A couple reasons for the design:

1. The BEC book specs that tube (in metric).
2. One of the SCCA roll tube specs was 1 3/4 x .109 (for a bigger car though)
3. The radius is large because it made sense to me for a single seat roll tube. It covers a large area on the sides.

The tube size is probably way overkill, but I do like the large radius. I could go smaller, but I still can only find around 7" dies.

I'll check with Rollcagecomponents.com

And I'll see what I can find on a 3 wheel roller/bender.

I found a youtube video of a guy making a large radius die by cutting a slightly larger tube in half, then making many cross cuts so it could be bent to the desired radius. Then welding plates and such to it. One side plate omitted for clarity.


Attachments:
die_cobbled_01.jpg
die_cobbled_01.jpg [ 61.34 KiB | Viewed 840 times ]

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."
Top
 Profile  
Reply with quote  
PostPosted: June 2, 2019, 9:51 am 
Offline
User avatar

Joined: July 17, 2008, 9:11 am
Posts: 5065
Location: West Chicago,IL
I've also seen dies being made with hardwood. It only has to survive a few bends. Google will get you there.

_________________
Chuck.

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

Visit my ongoing MGB Rustoration log: over HERE


Top
 Profile  
Reply with quote  
PostPosted: June 2, 2019, 10:43 pm 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 112
Oh that's interesting, a hardwood die. That's got me thinking I have some out-of-date tooling urethane I should use up. Cast that thick enough and back it with the steel plates and that should work. Like you say it's only gotta work twice.

_________________
"It ain’t what you don’t know that gets you into trouble, it’s what you know for sure that just ain’t so."


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 127 posts ]  Go to page Previous  1 ... 5, 6, 7, 8, 9  Next

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