Kurt H (hoffkm) SL-C build thread

Neil

Supporter
Thanks for the reply. I was looking at units with the capability of backdrive, but like you said it makes for more "switchology". I'm hoping avoid the need for a release pin and a way to re-set it in event of electrical issues. Not trying to takeover the thread, but has anyone successfully used a backdrive-capable linear actuator with gas pistons?
With gas pistons why would you need any linear actuators?
 
...instead of simply pulling the door down with your left hand? OK.

I mean, not trying to argue here but if all we wanted was auto-open a gas strut and solenoid unlock should suffice rather than a linear actuator? Heck, even my wife’s subaru has power open/close on the lift gate, don’t see why it’s odd to apply that to a door in this situation. The point of the ability to backdrive is so you can indeed open and close the door manually if so desired.
 

Neil

Supporter
I mean, not trying to argue here but if all we wanted was auto-open a gas strut and solenoid unlock should suffice rather than a linear actuator? Heck, even my wife’s subaru has power open/close on the lift gate, don’t see why it’s odd to apply that to a door in this situation. The point of the ability to backdrive is so you can indeed open and close the door manually if so desired.
If that is the way a person wants to configure his car, more power to him. Added complexity and added weight are the consequences but if those are not a problem, actuate away.
 
Took yesterday off of work to spend some time in my shop and de-stress. Have made some good progress over the past few months on my way to having the car road worthy late this summer for testing and tuning. This fall I will then take it all apart again for bodywork, paint, and interior finishing.

One of my original inspirations to building this car was Rumbles build and his paint scheme has been resting on my mind with a twist to the Porsche Guards Red color I have selected.

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My splitters (front and side) will be skinned in carbon fiber. The body is Guards Red, the roof is Ford Absolute Black, and the transition color is Ford Magnetic Grey (the wheels on my F150 are this color and I love it!) with Ford Absolute White pinstripes between the colors. What are everyone's thoughts on this paint scheme? I hate to be stealing someone else's vision, but I am putting my own twists on it.

My electric doors are finished, aligned, and working well.

I finished one of my tail light housings and have it mounted. It will be bodyworked later to finish out the 3D printed surfaces.

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I have all the wiring done in the interior. The rear view camera system is working as well as the stereo. It sure is LOUD in such a confined cockpit space.

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Working on installing the five point safety harness next.
 

Joel K

Supporter
Very nice progress Kurt. Looks like your 3D skills are really paying off. Nice job on the tail light bezels. Do you recreate those in fiberglass or just cover them in fiberglass? Just curious.

With regard to the paint scheme. I’m sure what you’re planning will look great. Certainly a lot of work. I like the following look which is simpler than what you are describing. I think black accentuates red better than gray. Maybe something like this with a gray pinstrip separating the colors…

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Joel,

Thank you for the compliments and feedback. My plan on the bezels is to prime the 3D printed parts with epoxy primer to seal the plastic and then to use body filler and polyester primer to smooth everything out. As long as the 3D printed material is sealed (it is very porous right off the printer) it will work just fine.

Like you, I have seen the photos and video of Alan's recent build in red and black. That is a VERY sharp SL-C to say the least. I have a year or more before I am ready for paint so I will probably change my mind a couple more times before then but that is half the fun, envisioning and re-envisioning what I am building.

Here is a photo of my F150 that is inspiring my color choices currently.


2019 F150.jpg


Decisions---Decisions---Decisions

The straight black and red scheme would certainly be much simpler but I am ready to challenge my painting skills. Painting the spider, doors, and rear clam will be a couple of intense days with a lot of mixing, masking, and spraying as I cannot fit all the parts at once in my booth so it will be two days for those parts alone minimum. I plan to take a week off of work to do all the final paintwork with many months of prep work before that.
 
My plan on the bezels is to prime the 3D printed parts with epoxy primer to seal the plastic and then to use body filler and polyester primer to smooth everything out. As long as the 3D printed material is sealed (it is very porous right off the printer) it will work just fine.


What material did you print the light housing in? I’ve had some PLA+ parts warp in the Texas sun, so I’m going back and reprinting everything in ASA.
 
What material did you print the light housing in? I’ve had some PLA+ parts warp in the Texas sun, so I’m going back and reprinting everything in ASA.

Alan,

I printed the parts on a Stratasys MC250 FDM type machine using ABS Plus material. It is a plastic that is similar to nylon only a little stronger. Most stereo lithography and poly jet parts are sensitive to UV light since they are cured with UV light. That is not an issue with FDM (fused deposition modeling) which is cured by heat.
 
Haven't posted an update in a while because there has not been much progress on the build unfortunately. My workplace has me traveling every other week and spending a week at a time away from home at our Greenville, SC sister company. This time away from home has cut my spare time down to almost zero. Before this assignment began I did manage to finish out mounting everything in the interior, finished the rough bodywork on molding in the rear clam vents, finished the rough bodywork on the rear tail light housings, started fabrication and mounting of my rear wheel wells and engine compartment closeout panels, fit the front clam and splitter, began mounting the splitter, and began fabrication of my own design for a front clam hinge. Once I get these tasks finished I will post up an update and pictures. Still hoping to get the fully assembled "raw" (not painted or finished) car on the road by late summer for testing and a couple of car shows up town. I will probably have to take some vacation days from work to be able to spend any time on the car at all. Got to keep my priorities straight!!

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Preview of my hinge design, I bonded some long 3/8 clevis from McMaster Carr into the front clam and am in the process of fabricating aluminum pivot brackets that mount to the front structure and the splitter. The splitter support rods will be mounted to the top of these for additional rigidity and strength.

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Getting some really good use out of my Bridgeport mill!!
 

Joel K

Supporter
Nice progress Kurt! Car is looking really good. I like the Lotus tail lights and the blending in of the rear window louvers.
 
We have had some rainy weekends so we have not gone camping and I have found some time to spend in my shop.

Finished and installed my rear wheel wells and closeout panels for beside the engine.

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I will spray bedliner on the wheel wells and will either polish or paint the close out panels in the "finishing stage" of the car.

Front splitter is installed and the front clam hinges are also completed.

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My front clam hinge works very well and is less noticeable than other designs. I just need to mount the gas springs to aid in raising the clam and holding it open.

Headlights and front turn signals are fit and I bonded in the headlight mounting brackets. For front turn signals I am using Kuryakyn halo headlights made for Harley motorcycles. These have a white halo LED for a driving light and an orange LED center turn signal. Since they are larger than the openings in the clam they are mounted from behind and will have a recessed look to them similar to the headlights.

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Once the 3M panel bonding adhesive cures on the brackets I will further reinforce them with fiberglass mat and resin.

I also started installing the panel latches. This small task proved to be a bigger time waster than I thought. Some longer fasteners will make installing the remaining two easier I believe. The includes fasteners are just long enough for the thickness of the fiberglass body. Plus, in hindsight, I should have mounted the front latches before installing the body. It would have been much easier that way.

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I will replace the two silver screws above with black flat heads once I get some longer ones.

Slowly proceeding along and getting very antsy to get this beast on the road for some testing this summer. I started it up for the first time in a long time the other day and she fired right up. Just need to finish the latches, mount the headlights, wire the headlights and tail lights, and get my inspection completed at the State Highway Patrol to be ready to title it and get it on the road! Then I will take her all apart again this winter for bodywork, paint, and interior work. Plus fixing whatever I find this summer to repair or improve upon.
 

Brian Kissel

Staff member
Admin
Lifetime Supporter
Nice job as always Kurt. Can you please show some more details on your front hinge ? I’ll be ordering my RCR Lola T70 next month and would like to come up with a hinge for the front clip for that as well.
Thank You

Regards Brian
 
Nice job as always Kurt. Can you please show some more details on your front hinge ? I’ll be ordering my RCR Lola T70 next month and would like to come up with a hinge for the front clip for that as well.
Thank You

Regards Brian

For my front hinge I bonded some 3/8 diameter threaded rod ends into the front clam for the pivot points.

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Holes were drilled very carefully into the "fangs" (as others have called them) of the front clam. The rod ends were then inserted using an alignment rod to keep them in line with each other and fiberglassed and epoxied into the body.

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Many layers of fiberglass were added to fill the fangs and they were finished off with epoxy to basically make this area solid.

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I then fabricated aluminum brackets that are bolted to the front frame structure of the car as well as the front splitter. They have milled pockets for the splitter support rods to fasten to them as well, adding more strength to the pivot points.

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The clam pivots on two 3/8 shoulder screws that are locked in place to prevent them from backing out by a set screw threaded into the hole from the opposite side.

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I will also be adding gas springs to open the clam and hold it up as others have done.
 
***************BIG NIGHT TONIGHT!!***********************

The SL-C is sitting back on the ground on it's own wheels.

In between still traveling for work every other week I have been preparing the SL-C to drive it to a couple of car shows this month. Our town holds a cruise in every Tuesday throughout the summer and the third Tuesday of each month is a "Super Cruise" where we have roughly 400-800 cars give or take show up downtown. (on the normal cruise ins we see between 30-100 cars) My boss at work (he is also a huge car nut, probably bigger than me and is really into Fieros) and I are planning to hold a car show at work for our fellow employees and then all drive up to the super cruise together. We are working to raise money for our charity organization at work. My boss is currently working to swap the motor in a Pontiac Mura he is working on restoring. He still has a lot of work ahead of him to be ready. We want to show both his Mura and my SL-C together.

I recently finished all the clam latches, mounted the headlights, and mounted the rear window. All I need to do before the car show is wire in the tail lights and headlights.

After the show I will setup my inspections at the State Highway Patrol to get my VIN and will then be able to transfer my plate and get insurance on the car. I then plan to drive the car for about a month to shake everything down before tearing it down again for paint, bodywork, and interior finishes.

Set the car back on the floor, hopped in, and she fired right up. Still needs a tune but she is running decent. Still wants to stall under light load (think parking lot cruising). The AC still works well and after a short drive in the neighborhood that gathered nearly every neighbor on our street to my driveway, there are no leaks anywhere. Feeling very good about things but only longer and longer drives will find any hidden gremlins.

I really got a sense for how LOUD the exhaust is when my first neighbor stopped over and I could not hear a word they were saying. Had to turn the car off. Luckily some of my neighbors are also car nuts so they will not mind the noise too much (or so they say).

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I had once again forgotten just how low this thing is. Good news is my lift works perfectly in my yard and driveway. The first approach leaving my driveway was a very slow, cautious moment with the AC off and door open listening for a dreadful "SCRAPE" that luckily never came.

I am way more graceful getting in and out with it on the ground than I am with it up on blocks. Also, even with the camera and the high mounted mirrors backing this thing up is not any fun, AT ALL! Oh well, as my brother would say, that is the price you have to pay to be cool (that was always his saying in reference to how painful it was to ride our old Shovelhead Harleys on long trips).

95% certain of the color scheme at this point.

Kurts SLC Guards Red black roof-5.JPG


Joel, you and my wife have me talked out of the gray transition color.
 
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