I've been researching roto-hammers to add one to my toolbox.
I've had good luck with Milwaukee products in the past,So that would be my first choice.
My primary uses are for driving ground rods, and drilling through concrete for SE cable (2" core bit or smaller)
However I would like the ability to drill to 4" if the situation arises.
What I don't fully understand is the difference between SDS,SDS MAX,or Spline Drive.
I'm also confused with the choice of "thinwall" and "thickwall" core bits and their specific applications.
Thanxs, Dave

Well, you're on the right track by first defining your need; that is, how you intend to use the tool.
In fairness, you will probably end up getting two, or even three, of these tools, for different size jobs.

For most of your needs, including core drilling up to 2 1/2", an "SDS" drive tool - the smallest of the batch- is fine. The tool is reasonably lightweight and handles well on a ladder.

The next step up is the "SDS Max" and "Spline" drives. These have a larger diameter drive shaft, and are used for more demanding jobs. They are the smallest tools to be of any help in driving ground rods, and a driving attachment is available (Use it!).
It seems that there is more available in "SDS Max" than "spline."

The final category are "demolition hammers." These tools hammer only, they do not drill. They are very effective in breaking concrete and driving ground rods- though hauling even the smallest (35 lb.) up a ladder is no fun. Typically, they use 1 1/8" hex shank tools.

All of these tols are pricey. While this forum has had many opinions expressed as to brands, I suggest that you rent various models, and find your own preferences before you part with the cash.

Bosch and Hilti are the only two I would consider on roto hammers, especially the size you'll need, and Hilti's a little more pricey. Spline has limitaions on bits and range, and what you want is high impact energy. Just get the job done! Some lighter ones just tap away at rods....
http://www.boschtools.com/tools/tools-detail?H=175982&G=54915&I=55056&T=1

[This message has been edited by e57 (edited 12-06-2005).]

SDS, SDS Max, and Spline refer to the type of chuck the tool has. Just like English and Metric the types aren't interchangeable. Generally speaking SDS Max and Spline are found on the bigger rotary hammers and SDS Max has pretty much replaced spline. Some manufacturers even have a "conversion" chuck that allows you to use, say, spline, in an SDS Max tool. That could be useful if you had an assortment of spline bits and buy a new tool.

I'd second the suggestion renting any tool you're considering buying.

SDS Max is becomming much more popular than spline. I can see it becomming the standard not too far in the future.

I have a Makita 4000(?) rotary hammer and I LOVE it. Extremely well made. As nice or nicer than the many Bosch drills I have used in the past.

I personally think Hilti is ridiculously over priced. Real nice and well made but come on. Maybe the big commercial and/or union shops can afford them, but not lil' ol' me.
And I have seen failures with them as well. I have a small Hilti 1/2" hammer drill. The armature went on it. I priced a replacement and it was more than a whole new drill from a comparable mannufacturer.

We have been using the Hitachi DH38YE 1 1/2" rotary hammers for about ten years and I will buy nothing else. They last longer and hammer harder than Bosch and Milwaukee hands down. Hitachi hammers cost much less and last longer. I have been very happy with the Hitachi SDS drills as well.

Been happy with our Milwaukee spline drive. Sometimes it will not drive a ground rod in all the way. It seems like the clutch kicks in too soon but it's well used so maybe something is wrong. Bosh is good too. Hilti is the top of the line but more pricy.

Tom

Hilti user here.

Not one complaint.....


Dnk....

If you want great drill bits for these drills at reasonable price...try this guy. He is from Canada, but ships anywhere.

I have bought several from him, not the *BEST* quality, but can't be beat for the price.

http://stores.ebay.ca/Hamilton-Core-Drill-Bits-Magnets_W0QQssPageNameZviQ3asibQ3astoreviewQQtZkm

You might consider one with interchangable chucks. I have a Metabo, I think it's a model KHE28 but don't remember for sure. It was a little more money but it takes the place of two drills on the truck. It can be used as either an SDS plus rotary hammer or a 1/2" keyless chuck drill.

I recently bought a Bosch SDS-Max from Fastenall and I love it! I also got an adapter to use my SDS bits from my other Bosch. I think I spent a little over $700.

... I have a Hitachi spline drive rotary hammer drill for big stuff,great drill for the money,only $379.00,I use it for ground rods as well,a Milwaukee SDS(plus?)for smaller stuff..whats the difference between SDS,and SDS plus,or SDS max..????
Russ

SDS and SDS plus are interchangeable.
>
> However, SDS plus drill bits have four large drive/engagement grooves and
when used in a SDS plus hammerdrill a stronger connection capable of more
rotational torque results. (SDS has only two of the large grooves)
>
> SDS Max is not interchangeable with either of above but is even heavier
duty.
>
> Spline Drive is not interchangeable with any above and is also heavy duty.

I have a Dewalt Spline drive hammer. It is big and heavy but knocks out big jobs in a hurry. I also have a Bosch SDS Plus which is variable speed. It handles a 3" thinwall core easily. I also have a 1/2" Jacobs chuck for the Bosch so I can run a 3/4" ship auger in the drill only mode or use smaller straight shank masonry bits. It is much easier to run a 1" brick chisel or bullpoint with the Bosch and it works nearly as fast at chiseling as the bigger Dewalt. The Dewalt is not variable speed. I would not buy a rotary hammer without variable speed if I had it to do over again. My only regret about the Bosch is I didn't get the model with reverse. That would come in handy when drilling in wood with the auger.

Thanks for the input, guys.

What I'm feeling here is that I should get either a spline drive or a SDS-max, so I won't limit myself down the road.

But what about the core bits? The ones I've used in the past had a pilot bit in the center. Some of the ones I've seen for sale have just a point in the center or none at all.( I wouldn't think that would work as well) Some of the core bits say that they're only recomended for fresh concrete, not cured concrete. Is that the difference between thinwall and thickwall?

Maybe I'm over-analyzing this stuff, but I hate to buy something and then find out I can't use it for what I had in mind.
Thanxs, Dave

Gidday there Dave,
If I need a Masonry drill unit, I swear by the Hilti.
I own 2 of these units, a TE-15 and a TE-25.
The TE-15 has 2 inter-changable chucks and can also be taken off of "hammer" to function as a standard Drill motor.
It has a 13mm 3-jaw chuck and the SDS chuck as 2 seperate units.
The TE-25 has just the SDS chuck.
You can use either of these units with a Core-bit, I've up to 100mm diameter in them and they really work well, really handy for boring holes in brick/concrete walls for A/C pipes/wires, as I used to do.
If you can burn out one of these drill units, you need to find another trade.

{Message edited because of a couple of typo's}

[This message has been edited by Trumpy (edited 12-08-2005).]

As far as the core drills go...the pilot (or point) of the drill is only of use when the drill is first getting started. Once you've got the groove cut for the teeth to follow, the body of the core bit is actually what guides it.
As you might guess, the ones with the "point" intend for you to remove the point once the bit is started.

I got a core bit from the same guy Sandro listed. Good seller. Bit works great for a few times a year. The pilot I got was too short though.

Tom