my advice would be to remove an attack out the cycle and redistribute the slots with end rec on the attacks/toggles left (use that power slot to start fitness), or go to 5 slotting with your toggles slotting just for end recovery until 18/20 or so's
bring the 3rd attack back in at 22ish and eventually go for the 2end/3res in toggles uill 30ish then respec and drop tehm to 4 slots.
@ExtraGonk
Your power selection and slotting looks quite reasonable (although you don't need to slot an accuracy into taunt unless you take him into PvP as it's auto-hit in PvE).
In general, I've found that the problem with building a tank for both teaming and soloing at lower levels is that it's almost impossible to strike the right balance between endurance management, offensive ability and survivability so that you can actually solo effectively while still being effective as a tanker on a team. At one extreme if you have well slotted attacks enemies will be defeated quicker while soloing and endurance use will be less but your defenses won't be that great so you'll need to defeat them quickly or you'll be in trouble (and if your poor defenses are getting you in trouble solo imagine how it'll be on teams). At the other extreme if you have well slotted defenses and poorly slotted attacks you'll be able to take more damage while you solo the mobs but you'll need that survivability due to the extra time it'll take to defeat them and your endurance use will be greater due to the extra attacks you'll need to use. With your current build I'd say you're more built for teaming than soloing (as youre a lot closer to the second extreme than the first) which, as you say, is leaving you in trouble when you solo.
If you're teaming mostly I'd recommend that you just learn to live with it and continue to build as you have been, with the main focus being on your defenses. Try not to solo too much as soloing an endurance-hungry, low damage tanker can be quite annoying. Your teaming experience will improve an awful lot once you pick up Invincibility and then again once you get to SO's as your survivability will increase a lot.
If you find that you're soloing most of the time I'd recommend you replace a few of the damage resistances in Temp Inv. and Unyielding with Endurance Reductions (until you get to SOs anyway) as solo I find it better to have a slightly less effective toggle that I can afford to run than a more effective toggle I can't afford to run. I'd also recommend that you throw some more slots into your attacks in the coming levels so you're able to defeat the bad guys quicker. However, this approach means you're less effective when/if you team and will be more likely to be defeated. Also while soloing you'll need to learn to manage your toggles - at lower levels don't leave Unyielding on all the time if you're facing mobs that don't mez (especially considering the defense debuff of Unyielding means you get hit more often when you have it turned on).
I know its a little late to say this as youve already started your character but personally I would either plan to build for 100% teaming (early on have very few slots in attacks, lots in toggles and Dull Pain) or for 100% soloing (early on have lots of slots in attacks, relatively few in toggles and Dull Pain) as the compromises you need to make to do both can leave you in trouble at times. I would tend to build for soloing until I get to SO levels and then if I want to team with that character Id respec into a team friendly build then but I'm an habitual soloer anyway so soloing the first 22 levels is business as usual for me - others mightn't enjoy that approach so much (plus if someone is playing their first tank they won't learn the valuable tanking lessons that they need to learn to play effectively at later levels).
Anyways, Im not sure how much of that is any use to you but I thought Id throw my thoughts out there. In the end it'll come down to how you play and what you want to do with the character. Just be aware that whatever you do, things improve a lot when SO's become available 
Defiant 50�s: Generalissimo, Righteous Bob, Splortch, Brutus Cayuga
Union 50's: Chimera Obscura, Diet Anthracite, Grim Proctologist, Puny Little Minion, Raging Bitumen
In Soviet Russia, mission farm you!
Energy punch you might want to consider removing, at higher levels. Barrage, Bone Smasher, Energy Transfer and Total Focus I find on my tank sufficient, with each attack and toggle slotted with one endurance reduction SO, and Stamina.
With Inventions approaching, endurance problems should become even less of a concern. I'm considering putting another slot or two into Health for the unique regen/recovery IO's and PIE set bonuses. Combat Jumping and Tough Hide may also prove more useful with +To Hit and +Recharge enhancements.
The Intrepid's / The Institution - Union Server Hero / Villain Supergroups
You actually only need to slot Temp invuln prior to DOs cos TOs dont do much. Unyielding prior to SOs cos DOs dont do much. Dullpain id of 6 slotted asap and haste would of been a boon. Your end is down to your attack chain mainly end enh in attacks are almost always better than end rec in stamina. In teams sadly you dont get invincible till 18 which could of had ya hoarding all the aggro so even without a defender ppls insps couldof gone to you as the team dont need them. Acc on taunt? not yet id go recharge and spam it about better acc is only good for pvp. Look at defense set in the team and see in what way theyd work best and offer them that.
I aim yo tank of the bat btw and only with teams that arent supportive ie pretty much with solo artists can ya suffer and dont tank for scrappers just controllers defenders and blasters are the main priority. Scrappers are designed to solo so you can share some aggro with then and almost all of the time will they be reasonably safe. (You must see many actually do some scranking surely?)
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
[ QUOTE ]
my advice would be to remove an attack out the cycle and redistribute the slots with end rec on the attacks/toggles left (use that power slot to start fitness), or go to 5 slotting with your toggles slotting just for end recovery until 18/20 or so's
bring the 3rd attack back in at 22ish and eventually go for the 2end/3res in toggles uill 30ish then respec and drop tehm to 4 slots.
[/ QUOTE ]
Heh this is a reason why i want to beat myself. In original build instead of bonesmasher there is Resist Physical Damage but i thought "Hah another attack will be cool". But i forgot about AS totally, which i found more usefull than Bonesmasher, i can knockdown enemies before they wander off disoriented.
Thanks for great replies i find it very usefull. But have a one question in mind, Knockback or up or down counted as mez, right? So for protecting myself from this annoying thing i have to turn on Unyeilding. This is what is confusing me, when to put up Unyeilding or not. In hollows Trolls love to knockback me, CoT Madness Mages love to mess with my fragile mind. Anyway i am not soo far from DOs and a respec is a must do for me. I think i can handle myself from nowon with your advices in my mind.
Thanks again. Oh one more thing should i slot Barrage further than one acc? 
with barrage and bonesmasher coupled with taunt you can afford to get and slot more primary powers as you have your bread and butter secondaries up until lvl 35 the only secondary attacks i have are Barrage, Bonesmasher, Taunt, Whirling Hands & Build Up
Heroes: Phobos-, Protector-Bot, Shadow of Ra, Bionic Eye, Entropic Chaos, Strike-Freedom.
Villains: Necron Phobos, Khorne-Berzerker, Full Metal Panic, Smasher Devourer, Degrees Kelvin.
Co-Leader of The Echelon
Visit us at http://www.theechelon.eu
Id advise on posting any build change ideas once again before you respec. Just incase of any misinterpretations.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
With the SO EndRdx i grabbed from caverns trial, things going so smooth now. After lvl 18 i continue to slot them with SOs and i think my problem will be solved. Thanks again for cool advices. With free rescep in my pocket i will get rid of Energy Punch (i don't like the animation anyway).
ach, energy punch is great 
give up on air super!
@ExtraGonk
[ QUOTE ]
ach, energy punch is great give up on air super!
[/ QUOTE ]
I am not totally giving it up, only get it after lvl 20. Last night i used my free respec and change EP with Elemental Resistance.
I played with all ATs except Kheldians so far and i can say Tanker is the most hard one to play right. But i am determined to carry KD as higher as i can.
aye sub 20 tanks can be painful.
i found my inv/em tanks latest I8 Spec, i've found it very fun - not defence or resist optimal at all but still very fun:
---------------------------------------------
Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder - (http://sherksilver.coldfront.net/index.php)
---------------------------------------------
Name: gonkeh
Level: 50
Archetype: Tanker
Primary: Invulnerability
Secondary: Energy Melee
---------------------------------------------
01) --> Temp Invulnerability==> EndRdx(1) EndRdx(3) DmgRes(5) DmgRes(7) DmgRes(9)
01) --> Barrage==> Acc(1) Acc(11) EndRdx(31) EndRdx(39) Rechg(45)
02) --> Dull Pain==> Rechg(2) Rechg(3) Rechg(5) Heal(7) Heal(11) Heal(13)
04) --> Energy Punch==> Acc(4) Acc(13) EndRdx(29) EndRdx(39) Rechg(45)
06) --> Hover==> Fly(6) Fly(17) Fly(34)
08) --> Unyielding==> EndRdx(8) EndRdx(9) DmgRes(31) DmgRes(40) DmgRes(46)
10) --> Taunt==> Rechg(10) Rechg(15) Rechg(25)
12) --> Hasten==> Rechg(12) Rechg(15) Rechg(17)
14) --> Swift==> Fly(14) Fly(43) Fly(43)
16) --> Fly==> Fly(16) Fly(43) Fly(50)
18) --> Invincibility==> EndRdx(18) EndRdx(19) DefBuf(19) DefBuf(21) DefBuf(21) Taunt(42)
20) --> Health==> Heal(20) Heal(34) Heal(42)
22) --> Stamina==> EndMod(22) EndMod(23) EndMod(23)
24) --> Bone Smasher==> Acc(24) Acc(25) EndRdx(29) EndRdx(40) Rechg(40) Rechg(46)
26) --> Tough Hide==> DefBuf(26) DefBuf(27) DefBuf(27)
28) --> Whirling Hands==> Acc(28) Acc(34) Rechg(37) Rechg(45) EndRdx(46)
30) --> Build Up==> Rechg(30) Rechg(31) Rechg(33)
32) --> Unstoppable==> Rechg(32) Rechg(33) Rechg(33)
35) --> Energy Transfer==> Acc(35) Acc(36) Dmg(36) Dmg(36) Dmg(37) Taunt(37)
38) --> Assault==> EndRdx(38) EndRdx(39)
41) --> Char==> Acc(41) Acc(42)
44) --> Fire Blast==> Acc(44)
47) --> Fire Ball==> Acc(47) Acc(48) Rechg(48) Rechg(48) Rechg(50) EndRdx(50)
49) --> Stun==> Acc(49)
@ExtraGonk
AS is a great filler i slot mine with 2 acc just to make sure i hit. with its great recharge you can often do for bosses without them gettin off a shot.....the biggest thing you have to worry about in later levels is end drainers and AS ties them up in knots!!
Air sup is great -fly, very useful to keep foes grounded which in some situations is a very, very, good thing.
Holy Thread Necromancy btw.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
[ QUOTE ]
ach, energy punch is great give up on air super!
[/ QUOTE ]
AS is only a tiny bit less powerful than EP when slotted up with SOs, according to Hero Builder, so it's a viable replacement if you want to squeeze another primary power in, but personally I love the animation on energy punch (makes a great boxing 1-2 with Brawl - hey, so sue me! ), I wouldn't want to have another power with the same animation as Bone Smasher, and I love having my red buttons in a row.
Inv/Eng is the first tank I've really enjoyed and taken up to lvl 30. For some reason the SS attacks didn't do it for me feel-wise (mainly I prefer the "ka-thud" of EM sounds), and Stone/Fire while very solid was just annoying because of the -run (it requires a different style of tanking, I prefer jumping about).
Looking forward to the "big hitter" attacks at 35 and 38.
Finally i made KD Tanker again. While he's a BS/Regen scrapper everybody keep saying to me "You are not a tanker" or "You should make a tanker". So here i am thinking about serious end problem of him.
---------------------------------------------
Exported from Ver: 1.7.6.0 of the CoH_CoV Character Builder
---------------------------------------------
Name: K. Defender
Level: 14
Archetype: Tanker
Primary: Invulnerability
Secondary: Energy Melee
---------------------------------------------
01) --> Temp Invulnerability==> DmgRes(1)EndRdx(3)DmgRes(5)DmgRes(9)
01) --> Barrage==> Acc(1)
02) --> Energy Punch==> Acc(2)EndRdx(3)Dmg(13)
04) --> Dull Pain==> Rechg(4)Rechg(5)Rechg(7)
06) --> Bone Smasher==> Acc(6)EndRdx(7)EndRdx(13)
08) --> Unyielding==> EndRdx(8)DmgRes(9)DmgRes(11)DmgRes(11)
10) --> Taunt==> Acc(10)
12) --> Air Superiority==> Acc(12)
---------------------------------------------
01) --> Sprint==> Empty(1)
01) --> Brawl==> Empty(1)
01) --> Gauntlet==> Empty(1)
02) --> Rest==> Empty(2)
---------------------------------------------
It is his current build. I think my slotting is wrong or power choices. For power choices i will cripple till lvl 24 and will respec him. But for enhancements i am asking your advice. He can't stay on his feet so long without inspirations. When in teams it is better but in solo middle of the fight his end drops to zero. So toggles down and KD again kissing the floor.
I hope you can help me with this.