How To Convert a DD-WRT Router into an Access Point

I am hoping someone can help. I have a cable modem/router which I have to use stock firmware (Netgear C3700 if anyone knows a open source please let me know) and a WNR3500 Router that is wired and set up as an access point with DD-WRT firmware. I have a few problems/annotances I am hoping someone can help 1. Internet seems to drop now and them 2. Router Repeater Setup using WDS on Tomato/DD-WRT Dec 12, 2017 Reuse an old router to bridge devices to your wireless

There's a DD-WRT table of supported hardware that can probably help you. Oh, and all this is presuming that your definition of 'access point' is something like 'a way to connect a machine with a wireless ethernet card to the network' as opposed to some kind of walled garden setup. 2) one network, using a LAN port to bridge from wired to wireless:

Apr 04, 2018 DD-WRT Setup – HMA Support

I am hoping someone can help. I have a cable modem/router which I have to use stock firmware (Netgear C3700 if anyone knows a open source please let me know) and a WNR3500 Router that is wired and set up as an access point with DD-WRT firmware. I have a few problems/annotances I am hoping someone can help 1. Internet seems to drop now and them 2.

Reuse an old router to bridge devices to your wireless