anyone had any experience with this tiny fan unit from the UK

http://www.samsmodels.demon.co.uk/electric.html
it says its good for 20 inch span models so it could i use 2 for a 30 inch twinjet?

There have been many discussions over the last two years about this fan. There are at least 3 commercial models that use 2 of these. The consensus is 7 cells wired in series. Maybe 8 if you use nimh. They Draw about 12 amps, and produce ~2-3 oz static thrust per motor. Any more voltage on the standard motors will fry them. You can get upgraded motors that will take more volts, but don't produce a whole lot more thrust, maybe up to 5 oz total with a brushless system ($$$).

The 3 models are 2 different A-10 models and a S-3 Viking. Several members of this group have built similar size models. I'm currently working on a b1-b and an a-10. Stay around 12-17 oz all-up weight and you should be fine.

You can find more info on the fan by searching for kp44 or ejf200 on this forum or on these web sites.

http://www.eam.net/
http://www.electricjetfactory.com/

Clint

thanks for the help i didn't know that the kp fan was also known by other names

I was thinking of doing an Northrop a-9, a gloster meteor or even a su-25 frogfoot (to go up against all the a-10's and me262's out there)

It's more commonly known as the KP44, since it has a 44mm diameter. Whatever you build needs to be extremely light, due to the low thrust output. It's also relatively slow. I haven't been able to scratch build anything yet that's airworthy for more than a minute, but I'm getting some crazy idea of putting a pair on a mini-IFO, just to be the first one to use EDF indoor over here.

Check out my site - there are some resources on it there!

http://www.aerc.biz