Sorry, late to the party.
I developed a robot builder that I use. Seems to work OK. Excel based, but works also in OpenOffice, which is a free program:
http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=33264
Are you using the latest errata to Book 8? Under the latest errata, the arms have been given a volume. I think this means they're subtracted from the chassis volume, since other than the head any component with volume is subtracted from the chassis volume. It might mean that, like the head, they add to the chassis volume - ergo the storage needed for your robot would be a bit more because of the arms, and you'd have a bit more room. I need to get a clarification on that.
Excluding that, I get a 150-liter Chassis III-B out of your URP, you get another 7.5 liters for the head, with 134.7 liters of stuff inside it, excluding the arm question:
60-liter fuel cell
60 liters in grav suspension (needs 3 units to carry the projected load)
14.7 liter brain
Therefore 22.8 liters fuel for about 76 hours. I get weight as 227.85 kg empty. I'm not sure why we're different, maybe I missed something:
15 kg chassis
95 kg fuel cell
36 kg gravs
3.6 kg brain
3 kg voder
2 kg slave unit
1 kg radio
1 kg spotlight
4 kg zero-G maneuver package
0.75 kg head
0.5 each (total 1 kg) for the two visual sensors
0.5 kg audio sensor
20 each (total 40 kg) for the arms
25 kg laser welder as a mining laser
Hydrogen fuel is another 1.596 kg. With 165.4 kg load, your G's are down to 0.75 and it can't move in a normal 1G field. Can't carry more than about 60 kg. when in a 1G field, but that's only a problem planetside or in the ship's G-field. Anyway:
I get a Type-E fuel cell out of your URP - 50 Kw delivered. I'm getting a total of 61 Kw used:
24 Kw for the gravs,
1 for the brain,
2 for the voder,
2 for the slave unit,
1.5 for the radio,
1 for the spotlight,
1 for the zero-G maneuver package
1.5 for the head
1 (0.5 each) for the two visual sensors
1 for the audio sensor
10 (5 each) for the arms
15 for the laser welder
It's not clear whether you're using one E cell or two, but one F cell would provide the power needed with less volume used than two E's, though of course it cuts your fuel, so you might want to grow the head a bit to get room for more fuel.
Add: Oh, forgot one point. Any robot using a grav-based propulsion automatically has a dexterity of 15; see Book 8 under
The Universal Robot Profile.