Stix's Gen 3 Coupe Build - Striped Steel

[Blue Viking]

Awesome work, gonna be one of a kind for sure! Have you finished mounting the Pinion Flange yet? In the same process myself, interested to see if you were able to close the gap on the dust cover.

[q4stix]

Hi, yes I got the dust cover in place too. I answered your question on the other thread you posted, but I think what worked in my application may not be best applicable to your application.

Here's hoping I pull it all off and have a working one of a kind and not a fun looking static display

[Blue Viking]

Sorry, didnt see this until now. Just picked up my new pinion flange and shortened driveshaft from the axle shop. Had to modify the flange they found for me, should fit nicely now. But also had to shorten the driveshaft a bit. A little welding to be done on the frame, had to cut out a piece where the parking brake bracket sits, but in the end, if everything works out as intended, the engine will sit in the stock position.

[RuffShod]

Wow!!!

[q4stix]

Suspension update....finally!

I was able to 3d print the two ends of my A-arms and I used some PVC pipe to complete the lengths of the A-arms to get the mock-up rolling along. A little bit of PVC cement and I was good to go (mostly). The legs are to the correct lengths as I designed them (rod end to spherical) and the diameters are close.


Here are a couple pictures of everything in place minus the pushrod.




Finally, here's how much the width change will be. The front has a track that is 2" narrower than the rear... all without any spacers anywhere.

[John Dol]

Not sure that's going to handle the G-forces with the PVC!

But seriously, great work. Going to need some serious fender flares.

John

[q4stix]

Yep! Flares will be a necessity

Not car progress, but progress on the mill to make parts for the car. I've been getting things prepared for painting the mill and have most of the things masked off (ways, mating surfaces, fastener holes, etc) and now a paint booth set up with the parts inside.


I still need fans and filters in place before I can start though. Does anyone know what the setup should be for them? I think I remember the booth should be pressurized but I can't remember if the filters are for incoming air, outgoing, both, or what. I'm also not sure how to not have my driveway covered in mist and my neighbors not breathing in vapor or misted. Any help?

[Alphamacaroon]

When I built my paint booth (still using it), I made it positive pressure. Two fans blowing in air, with filters, and then filters on the other side of the tent to let the air out. Incoming vents prevent dust from entering the booth, outgoing vents prevent overspray from ruining your garage/driveway. I went with positive pressure because I like the idea that if there were any small holes anywhere, it would push dust out rather than sucking it in. Seems to be working pretty well so far. The only hard part was figuring out how to create a doorway that was also sealed. I found some neat 7 foot long zippers (Home Depot) with adhesive sides that are used for creating zippered doorways in tarps— you just stick it on, unzip it, then cut the plastic in-between the zipper and then you have an instant, well-sealed, doorway.

[q4stix]

Awesome, thanks for the info! I'll hunt for the zipper you're referring to. Seems a lot easier than making a door

[Alphamacaroon]

Awesome, thanks for the info! I'll hunt for the zipper you're referring to. Seems a lot easier than making a door

This is the one here: https://www.homedepot.com/p/Homax-7-...3142/206526231, but it also seems like there may be some better ones out there. It works really well when it's finished, but it was a bit of a pain to install— the sticker peel-off was really difficult to separate.

[q4stix]

Reviving my own thread from the dead! Wow, didn't realize it's been so long since I've had a chance to make any real progress on things. Work has been full of challenges with projects, multiple late nights, and taking care of my own things too.

First up, I have the Bridgeport mill all painted and ready to start re-assembling. I was able to pick up a nice DRO and scales at an auction for a machining company going out of business. Hopefully those function well but too late to do anything about it now haha.


One of the work projects has been repairing and upgrading the electronics to a CNC machine in our shop. Since I took it on I've had to do lots and lots of wiring, re-writing code, installing circuit boards, contactors, etc. to get it going since the machine was fairly analog based with 80's era computer controls. As part of the proof I did things right, I have to test things each step of the way. Now that I'm able to run NC style g-code and I have the tool changer up and running, I dove in with my own test program and a big chunk of 4140 alloy steel I bought and brought in. Nothing like putting your money where your mouth is. Figure out which parts this block will be turning into.


As you can see, the tool paths all look smooth and consistent. Even after really ramping up the feed rates (450-500 SFM) for this machine and later finding a chipped carbide insert for some reason (these inserts can cut at 950 surface feet per min in steel), you can start to get a better idea of the parts in progress.


Sadly after this I'll resort back to my own resources since the testing phase of this CNC machine will be complete and it'll be put into true prototyping use.

Hopefully the updates will be a bit more frequent but I suppose that won't be hard to do after this long delay.

[q4stix]

Clearly I haven't been posting as much as I'd like but that's also because I've been constantly busy with other things which means the coupe has taken the proverbial back seat (which it doesn't even have!).

As a new update, I finally have things basically ready to weld up one of the lower A-arms for the custom front suspension required for the all wheel drive. All that is left is fitting up the tubes to the CNC'd outer section and drilling the hole for the pushrod in the CNC part. Since the test machining wasn't on a 4 or 5 axis machine I couldn't just punch in that pair of holes without fixturing the parts another time in the machine. Easier to just do on a manual mill later when I don't have to worry about holding up other projects.

[Snowman]

This is one of my favorite build to follow. It's gonna be a very unique and awesome coupe when complete!

[q4stix]

This is one of my favorite build to follow. It's gonna be a very unique and awesome coupe when complete!

Keyword "when" hahaha!

[q4stix]

And then there were two...


Now to start getting the uppers ready for welding and heat treat like the lowers.

[q4stix]

Now there are 4 A-arms and two push rods ready to be welded and heat treated. The sphericals locations will be bored out to after to allow for any distortion during heat treatment. The rod ends will come last.





I still need to make the upper mounting brackets or plates to allow for double shear on the bolts. After that it's upright / knuckle work. At the very least, when these are done it'll go a long way towards making me feel like I've had some real progress after such a long time.

[John Dol]

Those look great, not being an engineer myself how do you know what pipe size and wall thickness to use in a project like this?

John

[q4stix]

John - There are a few different things that determine it. I estimated the loading based on the car weight, cornering loads, etc.

From there I knew the geometry of the suspension and I set up 'free body diagrams'.... basically coordinate systems that show where the load is going with angles and such. Next is solving some equations and getting loads in each part. From there it's standard formulas that take into account tube material properties, cross sections, fixity (pinned-pinned because of sphericals), and a few other things. I've also got a safety factor in there because of plenty of driving unknowns like bumps and potholes, encompassing my estimates, and more. Most properties were assuming an infinite fatigue life which is super conservative.

The upper arm is sized by lateral loading, the pushrod by axial loading and buckling capability, the lower arm turned out to be sized by bending because I couldn't attach the pushrod as close to the upright as I would have liked because the front half shaft was in the way.

It seems a little daunting at first but looking at it in single steps and chunks makes it not so bad

[cgundermann]

This is my favorite build.

Hands down…

Chris

[Alphamacaroon]

Those are absolute works of art. It's almost a shame that they'll be hidden under the fenders. Almost.

Curious, how do you weld those? Do you just weld where they butt up, or do you drill a couple of holes or slots and fill weld so you get some joining where they overlap as well? I'm not a welder, so pardon if it's a stupid question

[q4stix]

Those are absolute works of art. It's almost a shame that they'll be hidden under the fenders. Almost.

Curious, how do you weld those? Do you just weld where they butt up, or do you drill a couple of holes or slots and fill weld so you get some joining where they overlap as well? I'm not a welder, so pardon if it's a stupid question

No stupid questions, I'm learning a lot of things too!
There are two variants that I'm aware of. One is to do a butt weld (which I'll be doing with a chamfered edge on each part to form a V to fill) and the other is to do that plus a 'rosette' weld which is drilling further towards the end of the tube end insert and doing a filling weld (sometimes just the tube, sometimes both). I plan to just do a butt weld but may do the rosette last min.

Butt weld only


Rosette weld:


btw, going to send you an unrelated PM

[Alphamacaroon]

Rosette weld— that's exactly what I was thinking! Now I know what to call it. Thanks!

[q4stix]

Welding time!
I had a friend and a friend of a friend come over to my place and get the A-arms and pushrods welded up. He has a lot of experience (training and job) and knowledge (degree) in materials / materials joining so really it was a no-brainer when he agreed to help with these. He has a new, water cooled Tig setup from Miller and was happy to have a project for it again.

Since the parts are 4140 and 4130 that I bought in the annealed state and I want to get them heat treated, he hunted down some 4130 filler rod instead of the typical ER70.. or ER80.. type filler. This would allow the weld area to be more uniform with the base metal and be able to be heat treated to the same levels instead of the ER series wire.

So... on to pictures.
I used my oven to get the parts preheated to 400F to help ensure the weld areas in the alloy steels wouldn't later crack. We then locally heated the weld areas with a MAP torch before welding began.


He welded all of the tube ends first. Notice the safe attire haha. He said it's the first time he's welded in sandals but not the first time in shorts. We experienced record breaking heat this weekend in Seattle so I couldn't blame him. Molten metal might have felt cooler with the humidity and heat we're not used to (typical 70s or 80s and it hit almost 110 at my place this weekend)


All the tubes were stuck in a bucket of sand to control the cool down rate after the ends were welded. When those were cooled we started the pre-heat cycle for the tubes to the machined lugs. Weld. Sand cool-down.


Final results!


I'll drill the pushrod holes after heat treat and bore out the spherical bearing holes to their final diameter to account for any shift or deformation during heat treatment:






I just dropped off the parts to a local heat treat shop (ok, a business that does large castings, machining, and heat treatment) that agreed to put my personal project in their flow since I asked for a fairly typical heat treat level of 150-160ksi.

Now it's a waiting game for them to anneal, heat treat, and temper before I can chase the threads in the ends and finish machine everything. In the mean time I'm finally getting back to moving the Bridgeport base in place to re-assemble that.

[John Dol]

Pretty cool stuff as usual. It’s nice to have accomplished friends!

John

[johnpinetree]

Phenomenal phenomenal build thread. Someone mentioned episodes on netflix, I feel the same way, only I don't watch TV. I prefer to spend my screen time reading amazing threads like this!

I almost feel bad inserting a Coyote question here (this thread really is like an art piece), but... like you I went with a gen 2 coyote and will go with an AEM Infinity (we chatted for a sec on the other forum). Question for you is: would you recommend going with the AEM harness and modifying that harness as needed? I've got no ECU at all right now... but figured what better way to start than by diving off the deep end??? I know you haven't been thinking about the Coyote lately, but mine just made it to Denver and am hoping to start some tinkering.

[q4stix]

I went with a gen 2 coyote and will go with an AEM Infinity (we chatted for a sec on the other forum). Question for you is: would you recommend going with the AEM harness and modifying that harness as needed? I've got no ECU at all right now... but figured what better way to start than by diving off the deep end??? I know you haven't been thinking about the Coyote lately, but mine just made it to Denver and am hoping to start some tinkering.

Hey! I haven't been able to be on the forums for 3 weeks so sorry if I missed a question on the other forum. Closer to back to normal now.
The AEM harness makes things really easy. Think of it as the equivalent as the Ford control pack harness for the Infinity. Both require the engine harness still. You can add in extra fuses and lines if needed too. I bought the Ron Francis harness with my kit before I knew about all the AEM harness stuff so I'm sure there is overlap between the two but that'll be ok. I didn't have to modify anything to get the engine running other than fixing a pin location mentioned in my earlier comments.

[q4stix]

Progress on two fronts recently...

First, the Bridgeport is finally getting assembled in position!
Base first


Then knee, turret, and ram. This accounts for a majority of the 'heavy' items. Once I replace the bearing in the knee that goes over the lifting screw, I'll be able to get the table put on. The head re-assembly will follow all of that.


Now for the front suspension update:
The arms and pushrods are back from heat treatment. At first I specified a minimum strength of 160ksi (160,000 lbs tension capability per square inch of material cross sectional area). I didn't specify a maximum because that was a fairly easy target to hit. I figured it'd come back around 180ksi. Turns out they figured they could skip tempering and that resulted in almost 240ksi. Way over the minimum so technically they met my requirements. Since stronger equals harder which equals less elongation and more brittle (in a relative sense, not like a ceramic brittle), I asked them to temper it lower. In the end it came out to 200-215ksi depending on the 4130 tubing and 4140 lug. Still has good elongation to prevent cracks due to bumps or road hazards but still strong enough to give me extra safety margin from what I calculated originally.


In this picture you can see where they removed the scale after quenching so they can do hardness testing (and calculate strength based on that). Look close and you'll see multiple, tiny dimples from the tester on the end and on the tube.


The dark arms are after heat treat, tempering, and quenching. The light is after a soft sand blasting to get the scale off. I don't think I'll polish or powder coat the arms but I will probably clear coat them after I solvent clean the outside to keep the metallic look but prevent rust on the alloy steel.


Next up is boring out the lug ends for the spherical bearings and grooving them for a snap ring. The lowers will also have the hole drilled for the pushrod rod end.
I'm also starting on the upright parts for the spindle, brakes, steering, etc.

[q4stix]

Onward with the latest

I did a quick test fit of the A-arms on the chassis and I think they'll work pretty well once I get some proper spacers/parts made to take up the gap between the arm lugs on the chassis and the rod ends. This will also be one of the ways I can adjust the caster in the front even though I'd rather the lower arms stay relatively fixed due to the pushrods connecting there.


The upright has also made progress with the LH/driver's side one. I started with a billet of 14lbs of 7075 aluminum and started machining away.


Mid progress before flipping:


The end result is an upright that weighs 5lbs, 2oz. Not super duper light but considering I'm doing hand calcs and conservative estimates (I hope haha), I don't think it's too shabby. If anyone wants to weigh the front spindle Factory Five provides to compare, feel free to post the weight of that.


Finally, this is the configuration of the front suspension including the upright, hub, brakes caliper and rotor, steering bracket, etc. There's still a few 3d printed parts I need to fabricate out of metal but the progress was good for a couple weeks.


Still on the list is boring out the a-arm lug ends for the spherical bearings and grooving them for a snap ring.

[Skuzzy]

Looks like fun!

[q4stix]

More two front progress. First the car:

I was able to bore out the holes for the spherical bearings at the end of the A-arms and also put in the grooves for the internal snap rings that will retain the sphericals. I'll get a couple more pictures once I clearcoat the arms since two of the ends I machined too undersized (not a big enough bore) for the press fit. I'll have to re-jig those two or figure something out. I didn't notice until I removed them from the jig because measuring the bore with a dial bore gauge requires decent access vertically. Live and learn


I created some spacers for the rod ends to the frame. Since the original a-arm setup from Factory Five has wide bushings and the rod ends are comparatively narrow, the gap had to be filled. Here's a simple, yet cool looking spacer I'll replicate for the locations.



Next up is finishing the spherical installs, clear coat the arms, make more spacers, and then finally install the arms to the chassis! And people talk about long waits on their suspension parts backorder list

[q4stix]

Bridgeport resto progress:
Here's the knee components that lift and lower the table. Rather dirty and greasy.


The knee bearing that supports the weight of the table was just plain nasty. You can see the grease I picked out on the table below my hand. I then put it and the other parts in an ultrasonic bath. Thank goodness for cheap Harbor Freight jewelry cleaners and Simple Green


Components cleaned and ready to re-install. I was able to get the knee to raise and lower with the crank so that means progress!

[cgundermann]

Unbelievably mad skills - sooo nice!

Chris

[cgundermann]

Very, very, very nice work!

Chris

[q4stix]

More front suspension updates:

I got all of the a-arm spherical bearings and internal snap rings installed. The upper arms use a 'typical' spherical while the lowers that have more load through them and hold the weight of the front of the car up both use a wide ball spherical to take more axial load. Shown is an upper arm.


All 4 front arms with the spacers:


Rod end side to attach with the chassis. The washers are a set thickness which will later give me flexibility with alignment adjustments to dial in caster. I will have jam nuts before setting the car on the ground:


Lower arm with spacers on the chassis. Notice the gap that had me a bit confused at first:


Turns out the spacers were hitting the liner which was slightly thicker than the spec showed:


Instead of modifying the replaceable rod end, I narrowed the end of the spacer to clear the liner:


Upright progress is scheduled next

[cgundermann]

WOW - nicely done!

Chris

[q4stix]

I had a free night to work on the Coupe in the garage last night so I took advantage of that and started assembling all the components that I've been working to fabricate in little time increments available.

First up is the lower a-arm to upright bracket. I made the spacers to evenly hold the spherical bearing in the middle of the opening even though there's a bit of extra material on the arm itself. More on that later...


As a general rule of thumb for me, I didn't want to be threading into aluminum for a complex part in case the threads failed or got damaged. Didn't want to replace a complex part when I could more easily replace a simple part. This called for something to act like a nut that is captured in place. I've seen barrel nuts before so I replicated that. These are hardened steel rods that fit in the bores of the upright and are threaded. I matched the angle of the upright on one end to help with alignment since it's a blind setup.


Both a-arm brackets and upright all attached:


Some views of the tight clearances. Someone on Facebook commented on the caster angle but if you look closely you can see the lower arm connects in front of the wheel centerline and the upper arm connects just behind the wheel centerline giving me positive caster. The scrub radius is minimal even with the wide upper bracket because my wheel offset is +22 and that puts the pivot point just outside of center.



View looking inboard you can see the pushrod almost at the back of the upper a-arm. Once connected to the bellcrank it'll have a bit more clearance.


In the aft view looking forward, you can see the pushrod is really close to the CV boot. I thought it would clear more but obviously not, so I'll need to think about that one. I don't want it to rub and tear open throwing grease everywhere.


Finally, the front view looking aft. Here if you look at the a-arm brackets you'll be able to see a little bit of contact to the upper a-arm. I'll clearance that a bit and check where there's a rub with the upright at full droop and where full lock left and right will be. I have some rubbing and will need to disassemble it to see exactly where. Right now I have free movement up and down by a total of 4". I'd like to clearance that to get 2.5" up and 2.5" down with full steering lock at the extremes. Not that I'd be at full lock in full compression, but I'd rather it not bind on me either.


So, more to do, but more progress too.

[cgundermann]

Absolutely incredible!

Chris

[Geoff H]

I agree! Amazing skill!
Thank you for continuing to post your progress.

[jdm65]

Can't believe this is the first time I'm seeing this - incredible work!!

[q4stix]

Thanks everyone!

No big news to report yet, but I've been trying to work to get the passenger side suspension to the same state that the driver's side is at.