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Learning how to build Lotus Seven replicas...together!
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 Post subject: Not Yet Named
PostPosted: November 30, 2018, 10:47 pm 
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Joined: December 29, 2012, 11:27 pm
Posts: 12
Hello All,

This thread is to log my build project. I encourage all constructive criticism regarding my design/fabrication as I want to build the best car I possibly can with the budget & goals that I have.

Background:
I'm a 22 year old Aerospace Engineer with a focus in control systems. I currently work full-time and do grad school part-time. I also have a girlfriend, but I'd say we have a pretty relaxed/low-maintenance relationship. That being said, all of that stuff inevitably eats up time I could be dedicating toward the build. :roll:
I was maintaining a 60-70% savings rate with the goal of retiring very early, but decided I am too career ambitious and liked my job too much to plan on walking away at age 30. Plus, I could die or something at any moment so might as well pursue a dream project. I figure there is no point in saving up a lot of money and buying a super car at age 40-50 when I can just build my own fast car instead. Consuquently, I've loosened up my savings rate a little bit and plan on spending ~$5,000/year towards this build. I have spent about $5,000 already for 2018. I've broken the project up into three main phases which are discussed in the Build Plans section

Past Experience:
In high school, I was really into fuel economy so I turned my first car, a 2000 Ford Focus ZX3, into The AeroFocus. It was good for 50 MPG on the highway.
Image

Later in high school, I resto-modded a 1993 Geo Metro XFi as a more normal looking fuel economy machine.
Before:
Image

After:
Image

Since then, things have been a bit quieter in the automotive realm. In college, I spent more time on aerospace projects including rocket payloads, solid rockets, and liquid rocket engines. Over the years, I've built a diverse skillset that has positioned me to be successful with a large project such as building my own car. I still have a lot to learn, but now it's just a matter of time, money, and willpower to get this thing done.

Build Plans:

Phase I: Rolling Chassis, 1400 lbs, 200 HP, 7:1 lbs:HP
Phase I started about 2 months at project conception. Since then, I've been researching, designing, and spending money. My timeline for Phase I is now to the end of 2020.
During Phase I, my plans are:
-Finalize the vehicle architecture [Mostly complete]
-"Finalize" the desired suspension geometry (I understand this will likely need tweaks and revisions over time) [Mostly complete]
-Finalize the CAD model [In Work]
-Procure necessary tools and materials [In Work]
-Fabricate the tube chassis
-Fabricate suspension bits
-Mount the engine and transmission
-Complete interior fabrication and wiring harnesses
-Make the car street legal enough to get a VIN assigned. At this point, it will likely just be running and driving vehicle with an open tube chassis and the required lights, glass windshield, and more
-Take the engine and transmission back out, clean them up a little bit, add some goodies, and put them back in.

Phase I Goal: Drive on streets, compete in autocross and trackday type events

Phase II Fully Enclosed, 1600 lbs, 200 HP, 8:1 lbs:HP
For Phase II, I plan to full enclose the car with an aerodynamic fiberglass body. I anticipate this will be a PITA so I'm giving myself another 2 years for this portion of the build. The plan is to shape a fiberglass mold to the desired shape around the tube chassis, do a wet fiberglass mat layup with epoxy resin, and then go from there. I have composite experience with fiberglass, carbon fiber, and kevlar, but nothing on this scale. I am also used to vacuum bagging and using an oven for curing so I anticipate this will be a slightly resin heavy layup. This seems typical of most DIY garage composite work.

Phase II Goal: Drive on streets, compete in autocross and trackday type events

Phase III: Race Ready, 1600 lbs, 300-400 HP, (5.3-4):1 lbs:HP
-Race-Ready rebuild of the engine and transmission. Dry sump oil system, turbo/supercharge or high compression build, dog box engagement transmission, etc.
-Race Prep the car: Full containment racing seat, Certified Fuel Cell, New Wheels/Tires, etc.

Phase III Goal: Compete in SCCA and/or NASA competitive events

Design:
The plan is to build a mid(rear?)engine RWD vehicle with 2 side by side seats. The engine and transmission will be from the Honda K-series. I'd like the final vehicle weight to be 1600 lbs or less.
Right now, I'm eyeing the windshield from the Lotus Elise (Polycarb for around $580 shipped) or the Toyota MR2 (Glass). The windshield wiper (required by law) will rest in the upright position like Koenigsegg cars. 8)
The front wheels will be 17x7 with a 40-45mm offset and 205/45R17 tires (These may adjust some as the design converges towards a final weight distribution)
The rear wheels will be 17x9 with a 40-45mm offset and 245/40R17 tires (These may adjust some as the design converges towards a final weight distribution)

The main roll hoop will be 1.5" x .12" wall to comply with SCCA Hill Climb rules. Just in case I ever want to get into that... 8)
The rest of the chassis will consist of 1.5" x .083" round tubes, 1.5" x .12" square tubes, 1.5" x .063" square tubes, and 1" x .083" round tubes

Desired Car Height: 42-45"
Desired Front Track Width: 60"
Desired Rear Track Width: 58"
Desired Overall Width: 68"
Desired Wheelbase: 90-100"

Microsoft Paint Sketch:
Image

Unfinished In-Work CAD Model. Between work, school, and hobbies. Please hold criticism on this particular item. I'd say only about half of these tubes are in right place. I've be iterating so much that I've been getting sick of CAD and decided to take a break from it for a little bit.
Image

Front Suspension Design is decently detailed:
Image


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 Post subject: Re: Not Yet Named
PostPosted: November 30, 2018, 10:54 pm 
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Joined: December 29, 2012, 11:27 pm
Posts: 12
Progress thus far...

Built myself a wooden build table complete with leveling feet to compensate for my slightly sloped garage. It is 6' x 12'. After I got the table in place, I moved all my shelves into a spare bedroom right by the garage so that opened up a lot of space.
Image
Image

Found a K24A2 with about 200k miles from a 04 Acura TSX
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Found a K series transmission from a 2008 Civic Si. This comes with an LSD. Hopefully it's in good enough shape so I don't have to rebuild it right away.
Image

Sourced Miata uprights/Spindles for the front and rear along with the K series half shaft and the miata steering rack & column. I'm not yet sure if the steering column will be long enough.
Image
Image

My seat came in so I decided to mock some parts up on the build table. I went with the Kirkey 55 series. I am planning for 16" on the driver's side and 17" on the passenger side. I haven't decided on a layback angle yet but I'm thinking somewhere between 20 and 40 degrees.
[imghttp://i1271.photobucket.com/albums/jj621/AeroFocus/20181128_184608_zpstjnz5vtx.jpg][/img]
Image


Items on the way:
-Hobart Handler 210 MVP MIG Welder, some welding wire, and an auto darkening mask
I still need to pick up the shielding gas, other accessories, and knock the rust off my welding skills

-About 50% of the steel tubing has arrived. I scored a 25% off deal at Online Metals during their Cyber Monday sale.

Next To-Dos
-Start welding up practice pieces and cutting the cross section to check weld penetration
-measure, measure, plan, check, measure, cut, re-do, measure, measure, tack and start building stuff!

Next To-Buys:
-Welding Accessories
-Angle Grinder
-Portable Band Saw
-Shop Crane
-Control Arm Bits (Rod Ends, threaded weld-in bungs, etc.) I already have my upper and lower ball joints.


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 Post subject: Re: Not Yet Named
PostPosted: December 1, 2018, 8:19 am 
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Joined: December 22, 2006, 2:05 pm
Posts: 6050
I miss that kind of energy. Don’t worry though; you will be an old fart before you know it. I hope you mean investing when you say savings.

I built similar aero mods into my ford aspire. I got 56mpg without a kam back but I had a head start with only 63hp. Those mods really made a difference in the highway performance and noise too.

Polycarb scratches easily, is damaged by oil (from you or other traffic), and is not DOT legal. Inspectors generally require specific markings on the glass to pass.

I like that your lcas consider where the rack should be. Consider aligning the rear leg to point to the lbj ball instead to eliminate the offset, pulling the chassis end forward on the chassis as necessary for rim clearance at full lock, though you have extra room with a 17 inch rim. The longitudinal bolt in the lbj can be fit within short tubes with washers welded to the ends. The lca legs can weld directly to these tubes. Then just trim the excess from the short tubes, leaving a gusset around the bolt flange. Draw lines between the lbj center and the pivots to know where the tubes should be.

This a life-long hobby so don't take it too seriously. Pressure takes the fun out of it :cheers:

_________________
MV8

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


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 Post subject: Re: Not Yet Named
PostPosted: December 1, 2018, 11:32 am 
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Joined: March 30, 2011, 7:18 am
Posts: 1521
Location: central Arkansas
> fiberglass body

That will take about 90% of the effort...

A) Steve Graber, who did the LaBala kit car, glued together a bunch of foam blocks, then cobbled up a huge gantry router out of threaded rod and eBay bits. When it was done, he sanded the ripples out, laid resin over it, and had the male plug to make the body molds. If you don't want to make extras (like for replacement panels in case of damage) you can just lay glass right over the plug.

There advantages of the gantry router are that it saves about a zillion hours of sanding, making templates to ensure the curvatures on each side are the same, etc. And with modern prices, you can build a router dirt cheap.

Steve had a web site up with pictures of the router and descriptions of the process, but after he sold the LaBala business the new owner appears to have just let the whole thing fade away; grabercars.com is an ad site now. You might find some of the pictures at archive.org: http://web.archive.org/web/201109010000 ... ercars.com

B) Then there are details like window frames, door jambs, and all the other minutiae people get bogged down in. I strongly recommend this book:

https://www.amazon.com/How-build-your-o ... B01MUC1X9I

The author bought a show car, which turned out to be just a shell over a chassis. It The majority of the book is about wheelwell lips, headlight buckets, weatherstrips, door hinges, wiper linkage, and all the stuff it took to make the shell a practical street car. You can find all sorts of books talking about resins and weaves, but this one has what you're supposed to be *doing* with it...

C) CAD...

You're obviously comfortable with CAD, but as you get close to your final iteration you might want to consider making a scale model from balsa and cardboard. I wound up doing some fairly major revisions of my chassis layout when I built a model.


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 Post subject: Re: Not Yet Named
PostPosted: December 1, 2018, 12:05 pm 
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Joined: October 24, 2008, 2:13 pm
Posts: 3882
Location: Carlsbad, California, USA
You sound like a man with a plan. Good on ya!

We have members who have gone for high mileage vehicles, but as far as I know, no one has done a car with aerodynamic efficiency as the goal. That would be a very worthy undertaking and it sounds like it would be right up your alley.

Good luck to you. I look forward to following your build.

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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 Post subject: Re: Not Yet Named
PostPosted: December 2, 2018, 12:25 pm 
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Joined: December 29, 2012, 11:27 pm
Posts: 12
Miatav8,MstrASE,A&P,F wrote:
I miss that kind of energy. Don’t worry though; you will be an old fart before you know it. I hope you mean investing when you say savings.

I built similar aero mods into my ford aspire. I got 56mpg without a kam back but I had a head start with only 63hp. Those mods really made a difference in the highway performance and noise too.

Polycarb scratches easily, is damaged by oil (from you or other traffic), and is not DOT legal. Inspectors generally require specific markings on the glass to pass.

I like that your lcas consider where the rack should be. Consider aligning the rear leg to point to the lbj ball instead to eliminate the offset, pulling the chassis end forward on the chassis as necessary for rim clearance at full lock, though you have extra room with a 17 inch rim. The longitudinal bolt in the lbj can be fit within short tubes with washers welded to the ends. The lca legs can weld directly to these tubes. Then just trim the excess from the short tubes, leaving a gusset around the bolt flange. Draw lines between the lbj center and the pivots to know where the tubes should be.

This a life-long hobby so don't take it too seriously. Pressure takes the fun out of it :cheers:


The Lotus Elise glass is the perfect shape but it's about $1,500 for glass and only $580 for a 1/4" polycarb version. My state (Alabama) doesn't put a lot of info about the VIN assignment process on their website so I need to give them a call and find out what they're going to look for as far as DOT markings. The state code requires the safety glass but doesn't mention any markings. I know polycarb scratches easily but it's also a lot lighter. The plan would be to get a VIN with a cheap piece of safety glass and then pull a switcharoo for racing reasons. Of course, that would be illegal to drive on the roads.

I can get aftermarket 2000-2005 Toyota MR2 glass for about $300 so I might go that route instead and bite the bullet on the ~20 lbs and less ideal shape.

Toyota MR2 Front View
Image

Lotus Elise Front View
Image

If anyone has additional suggestions on an available, low cost, curved windshield, I am open to ideas.

Thank you for the tips on the lower control arms. I've been trying to optimize that a little more so I'll keep your suggestions in mind.

TRX wrote:
> fiberglass body

That will take about 90% of the effort...

A) Steve Graber, who did the LaBala kit car, glued together a bunch of foam blocks, then cobbled up a huge gantry router out of threaded rod and eBay bits. When it was done, he sanded the ripples out, laid resin over it, and had the male plug to make the body molds. If you don't want to make extras (like for replacement panels in case of damage) you can just lay glass right over the plug.

There advantages of the gantry router are that it saves about a zillion hours of sanding, making templates to ensure the curvatures on each side are the same, etc. And with modern prices, you can build a router dirt cheap.

Steve had a web site up with pictures of the router and descriptions of the process, but after he sold the LaBala business the new owner appears to have just let the whole thing fade away; grabercars.com is an ad site now. You might find some of the pictures at archive.org: http://web.archive.org/web/201109010000 ... ercars.com

B) Then there are details like window frames, door jambs, and all the other minutiae people get bogged down in. I strongly recommend this book:

https://www.amazon.com/How-build-your-o ... B01MUC1X9I

The author bought a show car, which turned out to be just a shell over a chassis. It The majority of the book is about wheelwell lips, headlight buckets, weatherstrips, door hinges, wiper linkage, and all the stuff it took to make the shell a practical street car. You can find all sorts of books talking about resins and weaves, but this one has what you're supposed to be *doing* with it...

C) CAD...

You're obviously comfortable with CAD, but as you get close to your final iteration you might want to consider making a scale model from balsa and cardboard. I wound up doing some fairly major revisions of my chassis layout when I built a model.


Interesting stuff about the router. I've played around with the idea of building a router like that and still might do it when the time comes. I've also been toying with the idea of getting myself a mini-mill from precision matthews and doing a CNC conversion on it. That would allow me to also make steel/aluminum parts and could also do the foam. But, my foam pieces would have to be much much smaller. I moved away from making the whole "plug" out of foam because I calculated it would cost me about $2,000 in pink foamular sheets to extend the cross sections to the whole length of the car. The best plan I could come up with to mitigate the cost was to build a OSB shell and then build my foam up around that to get the final shape.

Thanks for the lead on the book. It's not a bad price, so I'll probably pick that up when the time comes.

Lonnie-S wrote:
You sound like a man with a plan. Good on ya!

We have members who have gone for high mileage vehicles, but as far as I know, no one has done a car with aerodynamic efficiency as the goal. That would be a very worthy undertaking and it sounds like it would be right up your alley.

Good luck to you. I look forward to following your build.

Cheers,


I've toyed with a custom high MPG designs before but never pulled the trigger. Maybe I'll go down that route someday. For now, I've got a need for speed. 8)



My welder arrived yesterday. I went with the Hobart Handler 210 MVP which I picked up for $700 shipped after $100 rebate. The welder is dual voltage, but they shipped it with two 230 V plugs instead of one 115 V plug and one 230 V plug. I don't have 230 V installed in my garage yet so I wasn't able to try it out. I should have 230 V in my garage by the end of this month and will try to get them to send me a 115 V plug soon.
Image


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 Post subject: Re: Not Yet Named
PostPosted: January 6, 2019, 10:22 pm 
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Joined: December 29, 2012, 11:27 pm
Posts: 12
The project continues moving forward.

My dad (electrician) and I installed a 240V outlet in my garage so I can power my welder. For simplicity, we dropped the receptacle right out of the bottom of the box.
Image

Got my shield gas tank & did a little bit of practicing. Definitely need to get better before I start on the chassis. I also need to get a cart for the welder and tank before someone knocks over the tank. Luckily, I live alone at the moment.
Image

Went to the junkyard and found the miata windshield frame I've been trying to locate. Took some cutting, but I got it out with the help of a buddy.
Image

Image

Started looking at angles and different dimensions of the windshield
Image


Using a miata windshield gives me a decently curved glass windshield for aerodynamics. Plus, since miatas are so popular, I think it'll be relatively easy to find new glass in the future.

The only portion of the metal windshield frame I'm planning on using is the mounting flange for the windshield. It'll be welded directly to the rollcage and should look pretty seamless if it turns out how I am imagining.
I started digging into it so hopefully this gives a better idea of what I'm after. I still need to remove the middle perforated sheet metal and then I'll be left with just the windshield flange.
Image
Image

The gap across the remaining sheet metal is about 2 inches and converges down to a pinch weld seam. so my 1.5" tube should drop in and weld up pretty nicely.
Image

My only remaining concern with my approach is any warping caused by welding. Hopefully leaving the windshield in place keeps things squared up. If I can manage to not break the windshield throughout the build, then that would be nice too.

Used some scrap 2x4 cut offs to make myself a metal organization rack.
Image


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 Post subject: Re: Not Yet Named
PostPosted: January 7, 2019, 2:01 am 
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Joined: April 26, 2008, 6:06 pm
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Location: Under the weather. (Seattle)
hydrojim wrote:
Got my shield gas tank & did a little bit of practicing. Definitely need to get better before I start on the chassis. I also need to get a cart for the welder and tank before someone knocks over the tank.
You have steel, you have a welder, and you need welding practice. You don't need to 'get' a cart for the welder and tank...You need to BUILD one! :mrgreen:

Image

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Also follow my build on blogspot, tumblr, or instagram and twitter (GarageOdyssey)


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 Post subject: Re: Not Yet Named
PostPosted: January 7, 2019, 9:07 am 
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Driven5 wrote:
hydrojim wrote:
Got my shield gas tank & did a little bit of practicing. Definitely need to get better before I start on the chassis. I also need to get a cart for the welder and tank before someone knocks over the tank.
You have steel, you have a welder, and you need welding practice. You don't need to 'get' a cart for the welder and tank...You need to BUILD one! :mrgreen:


I know I know :roll:

I've been trying to avoid sinking time into other distracting projects, so I was thinking of just buying a cart. However, I can't really find anything that fits what I want so I might end up building one.


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 Post subject: Re: Not Yet Named
PostPosted: January 8, 2019, 9:17 am 
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Location: Waterloo, WI
Paging Jack McCormack... viewtopic.php?f=23&t=8984&hilit=lalo Mr. McCormack, please pick up the white courtesy telephone.

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 Post subject: Re: Not Yet Named
PostPosted: March 3, 2019, 8:10 pm 
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Joined: December 29, 2012, 11:27 pm
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More progress to share. Perhaps this thread needs to be moved over the the build-logs section... oops.

Built myself a welder cart / welding cart. It has capacity for 3 bottles so I can eventually expand to more machines besides just my MIG welder.
I would like to eventually get a CertiFlat table for it, but I don't have a urgent need for it right now.

Still waiting for some nice weekend weather to prime and paint the cart so I can call it done. It has been raining non-stop here. I sprayed it a little bit but didn't want to get overspray all over my garage.

Gonna add some shelves and hooks as well.

Image

Any feedback on the welds?
Image


3D printed some PVC fittings at work to mock up the roll cage. Not happy with the way it turned out so I'll print some more once our nicer printers (2nd extruder with soluble support) are up and running (waiting on parts).
My goal is to mock up the whole cage to ensure I'm happy with the roll bar and windshield placement before committing to bending tubes.
Image

I also started on the chassis "base" layer

The MDF table surface has been really nice for laying out all my measurements and angles.
Image

This is as far as I got this weekend before calling it quits. Nothing is welded yet
Image


Additionally, I ordered a tube bender, a pipe notcher, and all the rod ends & threaded weld bungs for my control arms


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 Post subject: Re: Not Yet Named
PostPosted: March 31, 2019, 9:31 pm 
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Semi-finished welding cart. Room for more machines and two more tanks. Need to add a bottom shelf, some hooks, and proper tank hold downs. It's usable for now.
Image

Woodward Fab WFB2 horizontal tube bender mounted vertically in a custom cart with a air/hydraulic ram. Works good!
Image

Good all my rod ends, spacers, etc. Using McGill Motorsports 1/2" rod ends with AN178 bolts. Very tight fit.
Image

Pretty proud of it A pillars. 5 bends in total.
Image

Got the try out my tube notcher. Works excellently!
Image

Progress!
Image

Image

End of the semester is coming up so probably not gonna make much progress for a month. Then, I'll be back to my steady pace.


Last edited by hydrojim on April 1, 2019, 5:24 pm, edited 1 time in total.

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 Post subject: Re: Not Yet Named
PostPosted: April 1, 2019, 11:09 am 
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Location: Carlsbad, California, USA
Nice job on the cart.

It's a little hard to take in the other work as the photos are so large. If you want to keep the photos large for details (usually selectable in a camera) and posterity, you can resize them to post here in MS Paint or similar Mac software,

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886


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 Post subject: Re: Not Yet Named
PostPosted: April 1, 2019, 5:27 pm 
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Lonnie-S wrote:
Nice job on the cart.

It's a little hard to take in the other work as the photos are so large. If you want to keep the photos large for details (usually selectable in a camera) and posterity, you can resize them to post here in MS Paint or similar Mac software,

Cheers,


Got it. I posted from my phone last night and I couldn't find anyway to get resized links from the imgur app. I got it sorted out now.


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