Drilling a straight hole in a concrete floor

[AbitNutz]

So if I go with a MaxJax I need to drill all the holes as accurately as possible. I've read people have had issues with the air hammer drill walking or drilling at less than vertical angles.

Has anyone tried to use a drill guide? Because if they have I'm curious where they got one for a air hammer drill big enough to do the job.

 

[DaleK]

Get a nice thick piece of hardwood and drill a hole in it with a press. Then drill through it

 

[bazzateer]

Just use a centre punch to start a hole. The drill bit should be fine once a small hole has been started.

 

[rlitman]

When I install multiple wedge bolts through a steel plate, I drill the first hole (a center punch helps a lot to prevent wandering), bolt the plate down, and then drill the rest, using the plate as the template. You need to be careful though to not scuff things up.

 

[buzz4041]

Use a Hilti drill. Should not have any problem unless you hit some rebar

 

[Zeke]

I will drill a pilot hole (at least part way) if the hole is much bigger than 1/2".

 

[gnxtc2]

What we use at work when drilling thru floors for conduit risers.

Billy T.
[email protected]

 

[AbitNutz]

Get a nice thick piece of hardwood and drill a hole in it with a press. Then drill through it

Brother that is smart and cheap! I have a drill press so drilling a perfectly vertical hole is a cinch. Along with all the others suggestions I feel kinda dumb for asking such a question. Using a center punch and the plate template to start with.

gnxtc2...I would love to have that drill guide but I bet that's no cheap "use it once and park it on the shelf tool".

I'm going to have to look up a "Hilti" drill. I've never heard of it. I'm sure it's not a Harbor Freight item...and that's probably a good thing.

 

[gatchel]

I'm going to have to look up a "Hilti" drill. I've never heard of it. I'm sure it's not a Harbor Freight item...and that's probably a good thing.

Definitely not harbor freight in quality and price. Hilti is a brand. A quality brand.

 

[sgdawson]

I used a piece of 3/4 plywood with a 7/8" hole as a guide to start the hole, then set up a pair of laser levels to stay plumb.

http://garagejournal.com/forum/attachment.php?attachmentid=166972&stc=1&d=1328398672

Having clean, straight holes made a big difference in the how well the anchors set and their alignment with the jack base plate (wish I thought of it before I drilled the first set of holes).

Steve

 

[saabman]

I used a wood guide when I installed my lift.

 

[Oggy]

http://www.us.hilti.com/holus/

Hilti would have you covered for the whole project (except labor), but it comes at a premium, you may be able to find them at a Home Depot near you... if not in the tool corral try the rental shop. Many of their products are second to none.

 

[HAP]

Alot of fault for not so straight holes is the lack of properly clearing the hole during drilling. Removing the bit during drilling and the use of a vacuum cleaner makes for a much better job if done throughout the drilling process. Those Hilti Star bits takes care of encounters with rebar with ease.

R,
HAP

 

[nateplumb]

Wow are you setting anchors or building rocket parts? Seems to me like everyone is making mountains outta molehills? Mark hole with sharpy or pencil. Line up your bosch hammerdrill I see you got the same one I do. Push down with moderate pressure pull trigger drill to depth pull out bit kick away dustpile clean hole one more time with drill. Set anchor insert tool beat the hell out of it. DONE. By the way I hope you are not use the quick bolts those are garbage use drop ins. Otherwise get it really clean and epoxy it.

 

[nateplumb]

What we use at work when drilling thru floors for conduit risers.

Billy T.
[email protected]

They call that a core rig? How many anchors have you set with it?

 

[jhelrey]

Hilti hammer drills are awesome! You can pull the trigger with a finger while pinching the drill with 2 others. No weight to be added, etc. Cuts like butter!

 

[bad_idea]

I drilled holes in the curb in front of the house for drainage pipes and rented a large hammer drill from home depot. It wasn't that much.

 

[nateplumb]

Hilti hammer drills are awesome! You can pull the trigger with a finger while pinching the drill with 2 others. No weight to be added, etc. Cuts like butter!

I have a bosch bulldog like in the pic above on my worktruck and in my garage. I also have my choice of several hilti's and built a hospital for a company that used nothing but hilti. I have used both alot drilled 1000's of anchors with both. That being said they are both great drills and equally capable I prefer the bosch because I can 1 hand it easier.