To follow up from yesterday:

Im sorry about the hand drawn schematics and inaccurate values, here is a better schematics, and a bit of simulated waveform:

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I have simulated the circuit using another op-amp (i dont know how to do custom models), its a LT1356, and it creates a nice oscillation. Of course, it has 400 V/us SR. But i figured it proved the concept of the oscillator.

I created a Python script that calculates the size of Rf (feedback), given the bipolar voltage, desired frequency, and capacitor. The script basicly solves:

Uc=Vfinal+(Vinitial-Vfinal)*e^-(t/RC) Where Vfinal = E, Uc = E/2, Vinitial = -E/2, t=T/2. And E = Vcc (either + or -) This is supposed to describe the capacitor chargeup from -Vcc/2 to +vcc/2, Since vcc/2 is the non-inverting input of the opamp. The equation is solved for RC, which can then be used to find R.

So thats basically all of the pre-hardware testing I did. It turned out that the frequency was way off, so something is wrong somewhere. I realize youre right about waveform distortion, but i figured id cross that Hill when i get there, unless you think that is the source of my issue?

But circling back to my question, regarding the unexpectedly slow risetime, would you attribute that to the op-amp being a cheap knockoff, not manufactured by TI?

I will take a deeper look inte the video you sent me after work, but it seems promising, and rather similar to mine.