Golf ball dimpling/fluting with drill press?

Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

Moderators: mpallett, bakerjw

Post Reply
Posts: 34
Joined: Thu Nov 04, 2010 10:36 pm

Golf ball dimpling/fluting with drill press?

Post by IslandTimes » Tue Nov 11, 2014 12:03 am

Anyone have any advice/experience with golf ball dimpling/fluting at home using a drill press and drill press vise?

My form 1 came back approved for my maglight-style suppressor, and want to dimple the tube at a depth of about .1" to cut weight and aid in cooling. Tube is stainless, with an OD of 1.550" and an ID of 1.350".

Was planning on sliding a pipe inside the suppressor tube for support, and using an automatic center punch to make sure the drill doesn't wander. Besides that I don't have much else of a plan. It's a pretty basic drill press, but it has a belt and pulley that I can adjust for speed. Would I want a faster or slower drill speed for the task?

Silent But Deadly
Posts: 385
Joined: Mon Nov 10, 2014 10:24 am

Re: Golf ball dimpling/fluting with drill press?

Post by propeine » Tue Nov 11, 2014 12:27 am

Your tube is only .1 thick... You'll be poking a lot of actual holes in your can. Doesn't sound like a good plan to me.

Drill speed is dependent on diameter though and is something you can look up once you've decided that. If you can control your depth of cut very well you could maybe use a ball end mill but it sounds like a lot of work and some intense layout for very little gain.

Then what are you going to do if you drill one in the wrong spot or the drill walks?

Silent But Deadly
Posts: 1209
Joined: Fri Oct 11, 2013 4:09 pm

Re: Golf ball dimpling/fluting with drill press?

Post by a_canadian » Tue Nov 11, 2014 12:49 am

Why not take it to someone with a lathe and the skills to turn stainless cleanly on it and have them drop the thickness to 0.07" or so? Have to know their speeds and use sharp tooling to avoid work-hardening the stainless (at least with some alloys), but it'd remove a heck of a lot more weight than dimpling, and with much reduced risk to the integrity of the tube. You really don't want to introduce thin spots and a bunch of stress risers all over a high pressure can. Much better to taper gradually in from the threaded ends, or even step it so the initial 1/3 of the tube is thicker then stepping down as pressure goes down inside. Of course if this is for .22"LR you could just take it down to 0.060" and probably be fine.

User avatar
Silent But Deadly
Posts: 750
Joined: Thu Feb 09, 2012 6:31 pm
Location: NC

Re: Golf ball dimpling/fluting with drill press?

Post by CMV » Tue Nov 11, 2014 7:30 pm

You don't want to flute it. Your drill chuck isn't designed for the lateral forces.

I don't see anything wrong with what you want to do. It will be time consuming. You will get better weight reduction turning the whole thing down vs dimpling. You will have more surface area after dimpling - how much that aids in cooling I have no idea. May be negligible, might make it cool down 5 min faster, but I'm betting on the former.

If your drill press doesn't have a depth stop you'd need to fabricate something to consistently let it travel down only a fixed distance - you don't want to trust eyeballing .050 depth thousands of times. But I don't see why you couldn't do it with a ball end mill. No need to center punch unless that's just how you'd prefer to lay it out & mark where to put the dimples.

Also consider how you will engrave it. You probably don't want to try to do that over a dimpled area.

I wouldn't worry about inside support for a .100 thick walled stainless tube - that's pretty stout. Hold in the vise with a pair of V-blocks (available cheap on eBay or Enco & cheapies will suffice for this). Just don't go crazy on the clamping force in the vise. The cutter will do the work and the greatest force you'll be putting on the tube is the clamping of the vise jaw, but of you go ape on it you could deform it. If I were doing it, I'd go with a larger ball end mill - at least 3/8 - 1/2. Test on scrap to see the final dimple size at .050 depth in the center of the bowl it cuts. The reason I would go larger is just the economy of not having to make a zillion dimples with a little cutter similar to an actual golf ball. Figure there are ~350 dimples on a typical golf ball so how many would be necessary to cover your tube?

You would need a better machinist than me to figure out optimal RPM for your material & cutter size. You would want to get that right as tool life will be an issue since you're making so many cuts & will eventually dull the center of the cutter. HSS vs carbide vs coated vs whatever, dry or with cutting oil (and if so, what type cutting oil) - whatever will give you best tool life. If you think you'll need 3 end mills to get through that many cuts, but 4 since you don't want to be 90% done & then stuck waiting on a tool to ship.

Did I mention time consuming? :) This will take a very long time.

"Sorry but you cannot use search at this time. Please try again in a few minutes"
"This board is currently disabled"
These things make me :(

Silent Operator
Posts: 70
Joined: Sun Feb 02, 2014 6:18 pm

Re: Golf ball dimpling/fluting with drill press?

Post by wp6529 » Wed Nov 12, 2014 10:31 am

It sounds like a job for a CNC mill with 4th axis, not a manual drill press if you want to keep what's left of your sanity. A $500 Harbor Freight mini mill (Seig X2, HF #44991) is a big step up from a drill press and will give you the side load capability for fluting when used with proper R8 collets. Never use an end mill in a drill chuck except for spotting, drill chucks don't take side loads and can come flying off.

User avatar
Senior Silent Operator
Posts: 145
Joined: Fri May 06, 2011 9:54 pm
Location: 66048

Re: Golf ball dimpling/fluting with drill press?

Post by RPM509 » Thu Nov 13, 2014 12:43 pm

What others have said ^

If you're intent on dimpling on a drill press, buy a $20, 1/4" ball mill, keep the pattern tight (edges overlapping),
don't go that deep and take your time.
"a butt tuba" - Palindrome

Silent But Deadly
Posts: 268
Joined: Mon Feb 18, 2013 4:00 pm

Re: Golf ball dimpling/fluting with drill press?

Post by c5_nc » Fri Nov 14, 2014 1:52 pm

Turn it. Down to 10oz here. This will be offered as a $15 (projected) service.


Post Reply