If so, can't you send pics or post??   Also what wattage bulbs ? Placement?  Or other things that helped chrono work indoors. I've got a prochrono that works well outside but not picking up indoors. Thx in advance. Matt

I chrono indoors and didn't need any mods.....maybe you have a special kind of chrono?

I have had friends say to shoot outside if possible, if not, use a 250 watt halogen work light.

Mount 2 picture frame lights with 15 watt bulbs on the sun diffusers.

I saw a diy thread somewhere, possibly on another site, a while back. The guy used Christmas tree lights (all white / clear) poked through a piece of white cardboard or something similar. It looked like it should work well. I bet if you search Google you'll come up with some ideas.

If you are going to build one you need to use incandescent bulbs such as appliance bulbs....





But.... They are not near as accurate as the electronic designed kits available now.

https://www.competitionelectronics.com/view-shooting-products.html?page=shop.product_details&category_id=7&flypage=flypage.tpl&product_id=23

Yep, $40 is a lot for a pc of cardboard and a lite bulb!!  Mine reflects the light instead of direct.  

But Kirks white bulbs may work as well, my bulb is clear glass...

You could most likely make one that reflects like the factory ones and paint it white....