LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently December 1, 2021, 1:45 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 171 posts ]  Go to page Previous  1 ... 7, 8, 9, 10, 11, 12  Next
Author Message
PostPosted: August 29, 2021, 1:52 am 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
I assure you Perry it won't stay that way for long.
Attachment:
Day 1.jpg
Day 1.jpg [ 343.02 KiB | Viewed 1589 times ]


My build table is a bit different from the typical locost style as I do not have many flat frame members at floor level. The twin outer rails allow me to position the cross-rails at the working position with either g-clamps or tack welded tabs. Vertical position is achieved by threaded rods and angle iron tube supports to hold things in the exact positions required while I go back and forth from the drop saw. I recommend paying to watch the Tim McAmis chassis build video on his website, it gives some really good guidance and I got a lot of ideas from him. It's easy to take measures to the datum plane as it's on the underside of the cross rails. Since NZ is currently in full Covid lockdown I have not been able to tap an M16 thread into the foot plate for height adjusting - will be easy to add later. In true locost fashion I bought the leveling bolts in a hardware shop firesale about 6 years ago knowing I would need them eventually - they were 4 for a dollar.

To ensure that everything is built to the drawings I will shortly install the reference datum line running down the central axis and also another perpendicular at the center position. The datum line is high tensile steel wire known as No. 8 wire. I get a bit of a kick out of using no.8 as it's a big part of NZ culture, as due to our isolated location a lot of early pioneers were very creative with it's end uses - far beyond just fencing.
Attachment:
build table.jpg
build table.jpg [ 81.78 KiB | Viewed 1589 times ]


Top
 Profile  
Reply with quote  
PostPosted: September 2, 2021, 2:58 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 245
Noice. You mentioned Speeduino. Have you used it before? It sounds interesting, the attraction of having it "self" tune with a wideband O2 sensor is interesting (and it's open source).

_________________
"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: September 2, 2021, 5:47 pm 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
Not yet, but I am very close. Once I get a wideband O2 sensor and engine loom wired up I will be able to give some feedback.

The whole speeduino project really interests me, it started from a $50 dollar bet that Josh took to see if he could run a lawnmower engine on the Arduino. For me it's a cost decision, I am trying to get to the go/kill milestone with the least expenditure, but after proving the twin engine idea actually works I can see a lot more flexibility in being open source. I bought one of the V0.4 boards already assembled and even though it only supports 4 channels of fuel and ignition it can be configured to run a batch fire V6/V8 no issue - plenty are already. Plenty of rotaries and 4 cylinder builds are using it successfully.

A new version called the Dropbear was released in very limited numbers last month, however sold out in a few minutes. It's a greatly improved version using a faster processor and avoids the arduino mega hardware limits. It runs 8 channels fuel and spark sequentially, however due to chip shortages will not be available again for a while. https://wiki.speeduino.com/en/boards/Dropbear

The speeduino forum has some great projects, a vast majority of them are low buck since that is it's demographic. It's the fact that it is open source and DIY and even though the community is quite supportive, you REALLY have to help yourself to get it working. I like the idea of coding new options that suit my specific project - since the 2 engines in my car will not be mechanically timed to each other the crank sensors have to be totally independant and therefore I need to use 2 ECU"s - no product on the market caters for more than one crankshaft.

A peculiarity to my setup is the fact that any throttle during moving off could cause a rev rise on the unloaded engine and could wear/glaze the clutch prematurely. On the level the standard technique for a Mclaren F1 would be best (https://youtu.be/nk3DGaZ529E?t=117) as the engine torque even at idle is enough to get the car rolling. Using a pair of standard roadcar engines gives much greater flywheel effect compared to the f1, so would be an advantage in the "moving off without throttle" situation.

If the rev rise on unloaded engine is an issue during testing (and hill starts are when this issue would be obvious) I may have to put an extra idle adjustment feature into each ECU so if "zero road speed" and "clutch engaged" and "handbrake on" are detected the idle air valve opens to give a high idle (tunable from the drivers seat with a pot) so that the "loose " engine is prevented from revving up too much - it would almost act like an anti-stall. Once the clutch is fully released or road speed is above zero or the handbrake is off then high idle would be disabled. Trickling along in heavy stop start traffic is a good example of high clutch use and the tunable idle may be very useful for matching variable road conditions, although I must keep the system as simple as possible in the first iteration. It may seem counterintuitive but lightly applying the handbrake (enough to operate the switch but not the brake) could help the car move off smoothly in stop start.

Aluminium flywheels on drysumped race engines are on my future upgrade list if the Tbox works, but using the stock dual mass flywheels will prolong the life of the Tbox gears enough for me to get some development miles on the chassis while I build the bodywork. If the Tbox turns out to be as robust as I expect then converting over to less damping for the sake of throttle response is part of the long term plan.


Top
 Profile  
Reply with quote  
PostPosted: September 18, 2021, 10:24 pm 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
Under lockdown level 4 I have run out of steel to work on the frame, so have been plugging away on with the interior buck.

Turns out wood is not magnetic so my usual technique of holding the end of the tape measure to the metalwork can't be used until I started doing this, saves a lot of hassle.
Attachment:
woods not magnetic.jpg
woods not magnetic.jpg [ 128.28 KiB | Viewed 1397 times ]


The CAD model helps set the dimensions and my 3 favourite "working on your own" tools for turning MDF into a car interior are clamps, scissor jacks and ratchet tie downs. With these 3 tools you can very accurately position the sections while the glue sets.
Attachment:
extra hands.jpg
extra hands.jpg [ 359.4 KiB | Viewed 1397 times ]


The build table is a great flat surface for doing woodwork on, lots of clearance for the clamps.
Attachment:
worktable.jpg
worktable.jpg [ 237.3 KiB | Viewed 1397 times ]


With the aid of duct tape the position of the gearshift has been confirmed, moved it 12mm from where the CAD model was to get the right feel. The interior mouldings will be in separate pieces to allow fitting into the space frame, the drivers tub will be made first and transferred to the build table assembly ASAP so that the gearshift linkage can be proven out early in the build (essential to prove BEFORE the Tbox castings are made in case reality is different from CAD!)
Attachment:
Goldilocks position.jpg
Goldilocks position.jpg [ 389.06 KiB | Viewed 1397 times ]


Top
 Profile  
Reply with quote  
PostPosted: September 19, 2021, 4:53 pm 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 7151
Location: "Banana Republic"
Drywall screws are also effective and can be readjusted.

I've not been able to buy blue rustoleum in quart cans for a while now.

_________________
My posts are my own opinion and do not represent an official public position by any other person, place, thing, animal, vegetable, mineral, etc.
https://www.azsenaterepublicans.com/audit
https://www.oann.com/india-govt-declares-most-populated-state-officially-covid-free-after-widespread-use-of-ivermectin/
https://www.oann.com/fauci-hhs-officials-discuss-using-new-virus-from-china-to-enforce-universal-vaccines-in-footage-from-oct-2019/
https://www.oann.com/the-story-of-iverm ... -the-drug/
https://pubmed.ncbi.nlm.nih.gov/33278625/
https://rumble.com/vokrf7-sen.-johnson-expert-panel-on-federal-vaccine-mandates.html


Top
 Profile  
Reply with quote  
PostPosted: September 25, 2021, 4:05 am 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
Clamped a couple of 30mmx30mm box sections to the build table and tensioned the datum wire by backing the M16 cap head out of its nut. The wire runs through a hole drilled in the cap head screw so that the distance between the opposing wire crimps is increased until the right "twang" is reached. The magnetic tape measure sticks to it easily and there is no deflection even against a gentle pull, so will weld the uprights in place and use the wire as the datum for polar co-ordinates while building the frame. The crossbeam just touches the top of the line at the center position , so there is no measurable sag. The perpendicular transverse datum will be run just below the longitudinal datum. Will borrow a transit to check at all positions on the "table", but its looking useable to the calibrated eyeometer.

Attachment:
datum line.jpg
datum line.jpg [ 337.07 KiB | Viewed 1198 times ]


Top
 Profile  
Reply with quote  
PostPosted: October 1, 2021, 11:25 pm 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
Won't be posting any of my welding for a while as this site has rules about offensive pictures. However to give morale a boost decided to pull forward a few years some bodywork trials - full scale rear plug underway. Going the route of CNC cut foam, covered with epoxy and glass to form a sandable shell for priming, then pull a female mould off the plug. Cardboard laminations proved too time consuming to assemble.

Attachment:
Left rear.jpg
Left rear.jpg [ 209.6 KiB | Viewed 1093 times ]


The end goal;
https://www.infinitous.co.uk/ourshop/pr ... Panel.html


Top
 Profile  
Reply with quote  
PostPosted: October 1, 2021, 11:59 pm 
Offline

Joined: September 29, 2020, 8:24 pm
Posts: 101
Magnificent attention to detail, and I've been enjoying following along something this ambitious.


Top
 Profile  
Reply with quote  
PostPosted: October 5, 2021, 1:30 am 
Offline
User avatar

Joined: April 19, 2018, 2:02 am
Posts: 245
Foam looks nice, do you know what it is (blue, pink, syntactic, Renshape)? I also learned why I'll never own a McLaren, $30,000 for a used rear bumper cover! Lordy!

_________________
"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: October 5, 2021, 2:25 am 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
It's just plain old wall insulation - extruded polystryrene sheet just under 2' thick. https://www.expol.co.nz/expol-x/ not expensive either, home depot probably has something similar.


Top
 Profile  
Reply with quote  
PostPosted: October 5, 2021, 5:17 pm 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 7151
Location: "Banana Republic"
I lean toward the velorex trike body which is basically a vinyl tarp. You roll back the front for more ventilation. Brilliant! Not too late to take it in that direction. It would be a built in theft deterrent. Add a cup holder and your done.

_________________
My posts are my own opinion and do not represent an official public position by any other person, place, thing, animal, vegetable, mineral, etc.
https://www.azsenaterepublicans.com/audit
https://www.oann.com/india-govt-declares-most-populated-state-officially-covid-free-after-widespread-use-of-ivermectin/
https://www.oann.com/fauci-hhs-officials-discuss-using-new-virus-from-china-to-enforce-universal-vaccines-in-footage-from-oct-2019/
https://www.oann.com/the-story-of-iverm ... -the-drug/
https://pubmed.ncbi.nlm.nih.gov/33278625/
https://rumble.com/vokrf7-sen.-johnson-expert-panel-on-federal-vaccine-mandates.html


Top
 Profile  
Reply with quote  
PostPosted: October 5, 2021, 5:42 pm 
Offline
User avatar

Joined: March 19, 2011, 10:22 am
Posts: 2124
Location: Holden, Alberta, Canada
Miatav8,MstrASE,A&P,F wrote:
I lean toward the velorex trike body which is basically a vinyl tarp.
Ha Ha Ha Ha, I have a whole file full on my laptop of the Velorex. Once I finish my XS400's and the Super Slant 6 Seven build, a Velorex build would blend all my passions into one, bike build, car build, and covering it like I covered my Bushmaster II airplane.

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O.
Perry's S10 Super 7 The 3rd
Perry's 4th Build, The Topolino 500 (Little Mouse) Altered
Perry's 5th Build, the Super Slant Six 7


Top
 Profile  
Reply with quote  
PostPosted: October 5, 2021, 7:55 pm 
Offline
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 7151
Location: "Banana Republic"
Heck yes! I look forward to that build.

viewtopic.php?f=32&t=16054

_________________
My posts are my own opinion and do not represent an official public position by any other person, place, thing, animal, vegetable, mineral, etc.
https://www.azsenaterepublicans.com/audit
https://www.oann.com/india-govt-declares-most-populated-state-officially-covid-free-after-widespread-use-of-ivermectin/
https://www.oann.com/fauci-hhs-officials-discuss-using-new-virus-from-china-to-enforce-universal-vaccines-in-footage-from-oct-2019/
https://www.oann.com/the-story-of-iverm ... -the-drug/
https://pubmed.ncbi.nlm.nih.gov/33278625/
https://rumble.com/vokrf7-sen.-johnson-expert-panel-on-federal-vaccine-mandates.html


Top
 Profile  
Reply with quote  
PostPosted: October 5, 2021, 10:21 pm 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
Now that I have seen the velorex, I can't unsee it. Should have come with a warning or something - I see what you mean about inbuilt anti theft. Still I do admire the cost conscious nature of the design, but I think for now I will hold the course - maybe the cupholder can be incorporated somehow - I seriously have not made provision for one.


Top
 Profile  
Reply with quote  
PostPosted: October 8, 2021, 11:14 pm 
Offline
User avatar

Joined: April 23, 2019, 4:30 am
Posts: 221
Mucking around with the CNC router settings to try and improve cutting times, but learned the hard way that push too fast and the material balls up on the cutter and ruins a perfectly good part. Made a 1/10 scale part to test the 1/8" cutter settings.

Attachment:
Right rear.jpg
Right rear.jpg [ 160.73 KiB | Viewed 803 times ]


Next priorities are;
test engine frame (welding and tube fitting practice)
finish the interior seating buck
get the suspension bump steer measured


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 171 posts ]  Go to page Previous  1 ... 7, 8, 9, 10, 11, 12  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 7 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