LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently June 24, 2017, 1:15 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 81 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Author Message
PostPosted: March 8, 2017, 9:39 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
Update: was fried from work last night and the girl was at Rock school all evening (tying up the other women in the house). So I go to the garage with evil in my heart and 5/8" rod end suspension br@ckets in my sight. Check to see if they will fit inside of a 1.25" tube as a support and lo, they might, but not so well. Hmm. Check the front br@ckets and lo, the rod end won't fit there either. But this I know how to fix, and after a distressing day in the rat maze, a bit o angle grinding is just the thing.

So, still have rear br@ck#¥s to build, but I think I'm gonna just get that gas tank bolted in and worry about suspension on the weekend.

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: March 11, 2017, 3:10 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
Goofing around a bit more with vsusp. Given all the dead puppies from the last suspension discussion, I offer this without comment. Feel free to comment, however. I don't mind a good flambé of my work, as I pretty much know nothing, but do please be kind to other people.

Also, my design criteria came down to this: I could either control the roll center or could get a smallish camber change in bump, but not both. I went with roll center control. This, based on the dead puppy discussion, seemed to be the one least likely to give me surprises. I make no claims that this is sensible.

http://bit.ly/2mNkTSe

Also, to remind folks, I am using Miata uprights.

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: March 18, 2017, 9:54 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
Today was a lot of time delivering small but positive progress. I got the tank mounts drilled, nuts welded and checked. Perfect line up.

Boyd Welding, who made the tank, thoughtfully installed gusseted bolt-down br@ckets. Not, perhaps ideal, but I suspect that this will prove sufficient for my mostly non-track use after appropriate washers, cushioning and the like are added. Looks nice installed, BTW.

Next up, see where the tires are going to line up in back, and see how far out I can place the chassis rails around the engine. Maybe I WILL be able to get the engine in and out without separating it from the tranny.


Attachments:
File comment: gas tank mounts
gas tank mounts.jpg
gas tank mounts.jpg [ 99.97 KiB | Viewed 723 times ]
File comment: gas tank mounted to the frame
tank mounted 3 18 17.jpg
tank mounted 3 18 17.jpg [ 103.53 KiB | Viewed 723 times ]

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224
Top
 Profile  
Reply with quote  
PostPosted: March 18, 2017, 11:21 pm 
Offline
User avatar

Joined: February 9, 2016, 8:46 am
Posts: 218
Location: New Jersey
Ooooh, Shiny Tank..... 8)

_________________
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!


Top
 Profile  
Reply with quote  
PostPosted: March 19, 2017, 12:06 pm 
Offline

Joined: February 12, 2017, 7:57 pm
Posts: 36
Where does your steering rack fit?


Top
 Profile  
Reply with quote  
PostPosted: March 19, 2017, 8:41 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
Great question. Maybe not the $64,000 question (we are building locosts after all), but pretty important.

The short answer is that I don't yet know where I am going to put the steering rack. The longer answer is that I have two options: 1. There is room in front of the tank. This is probably close enough to the Miata steering position to keep Ackerman in check. 2. I can place it in front of the front cradle. This probably will affect Ackerman, but by how much and to the detriment of driving? I have no idea.

I have two racks for the car at the moment. The one I have been testing everything with is a manual rack. That is really thin. The powered rack (which I may depower for its faster rack), is a bit thicker, but I still think will mount and clear the tank. In all cases, there is plenty of room for the steering arm to come in beside the tank.

So, now that you mention it, it is a good time as any to ask the group: What impact would moving the rack forward ~4" have on steering? If it isn't much, I will probably go with the forward mounting. It makes that space just a little less busy, and provides additional protection for the tank, rather than a little more danger. What you you guys think?

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: March 20, 2017, 9:15 am 
Offline
User avatar

Joined: September 22, 2005, 8:12 am
Posts: 1303
Location: 4AGE in S.E. Michigan
Moving the rack 4" will effect the arkermann, but it does sound like the wises solution. A locost is full of compromises. Dave W


Top
 Profile  
Reply with quote  
PostPosted: March 20, 2017, 5:11 pm 
Offline

Joined: July 1, 2009, 9:36 pm
Posts: 26
Location: Christchurch, New Zealand
Rack position is critical to stop bump steer ( ackerman is not the problem)... you have to have it very close to the stock position, otherwise it will be undriveable.

_________________
7ish


Top
 Profile  
Reply with quote  
PostPosted: March 20, 2017, 9:53 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
7ishNZ wrote:
Rack position is critical to stop bump steer ( ackerman is not the problem)... you have to have it very close to the stock position, otherwise it will be undriveable.


You are quite right. Vertical rack position is critical to bump steer. In the case of the Bauhaus, I have almost unlimited ability to position the rack in the vertical. The 4" we are talking about is the placement in front of the front bulkhead or behind the front bulkhead. No vertical positions will be harmed in the making of this car...at least not yet!

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: March 20, 2017, 10:26 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
davew wrote:
Moving the rack 4" will effect the arkermann, but it does sound like the wises solution. A locost is full of compromises. Dave W


This. I have no idea how "ideal" the Miata ackermann is in the first place. Plus, I am widening the track by quite a bit (to 64"), so that probably altered the ackermann anyway. So where does that leave me? I wish I knew better what I was doing designing suspension, but I am thinking that I should be OK.

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: March 20, 2017, 11:57 pm 
Offline
User avatar

Joined: December 24, 2007, 5:11 am
Posts: 611
Location: Seattle area
Here is a Miata front sub frame with rack and spindles in place. Notice that the rack is ahead of the center line of the spindles. I didn't do that, wish that I had.


Attachments:
locost_for_sale 019.jpg
locost_for_sale 019.jpg [ 365.47 KiB | Viewed 632 times ]

_________________
Larry in Seattle
Top
 Profile  
Reply with quote  
PostPosted: March 21, 2017, 8:37 am 
Offline
User avatar

Joined: September 22, 2005, 8:12 am
Posts: 1303
Location: 4AGE in S.E. Michigan
Typical Arkermann percentages are any where from 35% to 200%. Unless you start making custom steering arms there isn't an easy solution.
For over all handling the bump steering should be a higher priority. If your new rack mount is designed to incoprorate U/D shims, you should be able to dial out most of the bump steer. Dave W


Top
 Profile  
Reply with quote  
PostPosted: March 26, 2017, 5:18 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
Thanks all for the input on steering. Not sure if I will try to get it behind the front frame member or not, but I now have confidence nothing disastrous will happen. Hopefully I won't have to push it. :D

In other news, I got lucky on the windshield measurements. Somebody posted a lower channel for a 53-56 vetted on eBay. And wouldn't you know it, they posted measurements! Outside edge measures 52 1/4". Channel is about 1, maybe 1.125" wide. This puts the screen width at 51" give or take. Looks like a contender with the MGB (maybe 2" narrower).

The Bauhaus is pretty wide. The passenger area is 48" wide, with 1.25" rails (50.5" wide total). MG would be on the inside of the rails, vette on the outside.

And in other news, I started tackling the rear. Started. Glacial pace. Don't get too excited.

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: April 11, 2017, 5:11 pm 
Offline

Joined: September 15, 2014, 8:13 pm
Posts: 143
No progress update. Life in the way. But promising progress opportunity. At work, I got introduced to an IT/digital guy. Mind you, I work in Pharma, so it was a bit surprising to find out he started as a photographer, and ended his undergraduate career as a sculptor.

Over the usual weird banter, I mentioned the Bauhaus build and he asked me if I'd built a model. The meeting went well, and as we were wrapping up, he asked if I had a lathe. No? Well, would I like someone to build a clay model? So I gave hime key dimensions and he's going to take a shot at a design for me. Seriously! Life is cool.

_________________
Figuring out how to build in the bucolic garden state
Build log: viewtopic.php?f=18&t=18224


Top
 Profile  
Reply with quote  
PostPosted: April 11, 2017, 11:25 pm 
Offline
User avatar

Joined: February 9, 2016, 8:46 am
Posts: 218
Location: New Jersey
You just NEVER know who you are going to meet in life. That is just absolutely cool!

_________________
Certified Welder, Certified Welding Inspector, Full Time Car Freak...In New Jersey no less!


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 81 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  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