This height adjustable wall mount helmet stand is uses Command Strips.

Depending on your helmet type, the main support can be raised or lowered to suit your needs.

I use the adjustment to align the full vs half mask helmets on the wall so they look level.

The shroud hides the command strip nicely, and can be detached if you need to use the helmet via the three pins.

I used a pipe reamer on the holes in the arm before attaching them together, you can also cut the pins out and glue it if that feels better for your needs. I also support the inside of the bracket when attaching the arm as it is pretty thin. I added a few extra domes, if you want to be fancy, but I made them to reduce the weight for a heavier helmet. Two Large size command strips fit in the back and away you go, place it anywhere, without leaving holes on your walls. I have had big and small helmets hang off this for a couple years and never had any problems.

The screw has been split into 2 pieces to maximize strength at the weak points. Depending on your printers calibration, the hex head should fit into the dome, and once you screw it in the arm, there is no need for glue. If it seems tight in the adjustment, put a drop of lubricant in it. 

I have reduced the size of the main screw a bit to fit more easily, but once you have the height adjusted, you don't want it to be too loose.. I have tried at 100% as well, and it works just fine, but the slight reduction makes a bit of slack so you don't need a hammer to squeeze the parts together LOL

I have set it up with supports, but have also printed it without using them. The finish on the inside of the bracket is a bit nicer with the supports, but not required (Depending on your printers calibration obviously) 

You can also split the parts up and print the bits that don't need support separate, DO NOT use brim on the screw, or you will be screwed.. LOL. 

I have printed it with 0.20, and 0.24, they come out the same, just one takes longer.. HAHA ( admittedly, the screw is a bit nicer in the 0.20)

but it  works great, I have about 15 helmets hanging off these, and have never had an issue. I did however follow the instructions ont he command strips. ( Wipe mounting location down with alcohol, so it is clean, and let the strip bond to the wall for a few minutes before putting weight on it.

The instructions on the Strips say they will hold about 7.5 lbs with the 2 strips. If your helmet weighs more than that, I believe they offer a heavy duty version, but man, a helmet that weighs 7 lbs is usually made of steel.  My helms usually weight between 1 and 3 lbs.

Anyway, have fun, make helmets, and hang up for all your friends to be jealous of!