Power Supply & Gecko's

Hi All,

This is my first post and I'm hoping I can get some advice.

I have a retrofit bidgeport mill runing on steppers with Gecko
201/210's.

Current settings are two at 7.0 amps and one at 3.5 amps.

I have been driving the mill with a 24V 25 Amp regulated power supply,
for a few years.

I wanted to upgrade the power supply, so I've built one similar to the
"Simple Power Supply" in the files section, using a transformer I had
laying about.

I have 48VAC out of the transformer going through the bridge rectifier
(35A 400V) and then paralleled with a 22,000 uf Cap.
Result is I am getting around 70VDC as expected.
I am also measuring quite a bit of AC (around 150V), but it might be
because my multimeter is a cheap one (the 24 VDC power supply I have
been using for a long time also has an AC voltage (30VAC).

My problem starts when I connect up the Gecko's.
The 5A fuses blow instantly every time (are they big enough?)

I found another tap on the transformer that will give me about 30VAC
and therefore 42VDC, and this seems to work fine.

Any ideas on why I can't run the higher voltage.
I don't want to just try bigger fuses and risk the Gecko's unless I'm
sure they won't get damaged....

What voltage should I be aiming for?
I have just bought some new steppers which will be fitted soon. They
are rated at 5.0A and 3.7VDC.

Thanks

Tim