Would a barlow be of use in my setup?

Using nikon d7000, a stellarvue raptor 90mm refractor, orion 2 inch field flattener and I currently get focus at 5.35 cm on the 2.5inch focuser. the images understandably are small... if i wanted to try for a 2 inch barlow, would i have focusing issues? Any help appreciated...
dbb in chicago

A Barlow would give you a larger image scale and should reach focus OK. Image will be dimmer. I'd skip the field flattener; it probably won't work well with the Barlow in there -- the optical path will be very different from its design point. YMMV.

What are you trying to image? For faint stuff, the fact the image is dimmer with the Barlow will probably hurt.

For bright stuff like moon and planets, the Barlow will probably help overall. So called "eyepiece projection" is another way to get a large increase in image scale for moon, but it takes a special adapter that can hold both the eyepiece and camera. Another approach is the "afocal"
method where you leave the lens on the camera, and just stick it looking into the eyepeice -- helps to have an adapter for this, otherwise very hard to hold everything steady.