Need technical help on hrap3

Hi all,

Thank you for stopping by to read my post. I will cut to the chase.

Hrap3 push button (sanwa, hori n semitsu) uses 2 metal connector microswitches.

Happ push buttons uses cherry switches (always open {AO}, always close {AC} and ground)

My question is: I disconnect the two QDs crimped part from hrap3 push buttons. After doing so, I wish to connect the crimped part to the cherry switches, which two connection on the cherry switches should I connect the two crimped part to for the hrap3 pcb to receive signal from the happ push buttons?

Would love to hear any answers. Thank you for reading.

The switch should be labeled NC for normally closed, NO for normally open and COM for common (ground). The two wires go to NO and COM. It technically doesn’t matter which wire goes to NO and which to COM but you might as well connect the common to the ground line.

Assuming your switches are D4-series or equivalent, the terminals are: COM is the one coming out the bottom all alone and bent, NC is the one on top (same side as the plunger) and NO is the one in the middle.

Thanks for the great advice.

Just one last question, the crimped part connecting to the hori buttons are small. Is there any safe method to expand it so that it can fit the cherry switches connectors - normally open and common? Or can I use any sticky tape to hold the crimped part and the cherry switches connector together?

You can’t just tape or glue them on. You would need to attach a new connector to the wire. They should be available wherever you’re getting (or got) the replacement buttons. Cherry/Happ switches use 0.187" connectors, Sanwa/Seimitsu use 0.110" instead.

Also, I don’t know if the HRAP3 has enough vertical height to handle a Happ button. Also, Sanwa (and equivalent) buttons fit in 30mm diameter holes whereas Happ buttons are meant to fit in 1-1/8" holes. (About 28mm) So they may mount a little lose.

Also, are you sure you want to modify your HRAP? Did you give yourself enough time to get used to it before giving up on it?

Thanks bud,I opened up my hrap3 and i put a happ buttons along the interior of hrap3, they do fit into the metal faceplate nicely and there are still a little winny bits of room left from the base of happ… I ordered screw-on happ. So they wouldn’t move around. Worst case will be stick bits and pieces of paper into the mounting hole.

Regarding about the different dimension of the crimped part between sanwa and happ, are the difference only in size? Or there is more technical stuff involve?

If the difference is only the size, I will see myself using needle nose pliers, slowly uncrimping and recrimp onto the happ push buttons.

Willl recrimping work? I dun see my self as a soldering guy, I am of a crimping person. :slight_smile:

Maybe I was unclear. You have a circuit board. From the circuit board come a bunch of wires. Each wire has a quick disconnect crimped onto the end. These are currently .110" quick disconnects. These quick disconnects attach to the connector on the button. You need to switch the .110" quick disconnects for .187" quick disconnects in order to use the Cherry microswitches. The easiest way is to cut the wire just before the .110" disconnects, re-strip the wire, and crimp .187" quick disconnects onto the end. This does not require soldering, only crimping new quick disconnects on. Wherever you buy your Happ buttons should be able to sell you the quick disconnects and even give advice on crimping them on.

Again, you cannot use the .110" quick disconnects in any fashion on the .187" terminals on the Cherry switches.

It’s crystal clear. Thank you for taking the pain to explain to me. I will do as advised. Appreciate your help. :slight_smile: