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pb57
03-06-2015, 09:41 PM
I just got a new Acer milling machine and have it pretty well equipped now. I am in the process of building a 50 ton press. I will be using 6" X 1" hot rolled flats for the uprights, 2 on each side. I will be drilling about 40-1 1/16 inch diameter holes in the flat iron for the table to adjust up and down on. I will be using 4-1" pins holding the table in place into the 6" flat iron so I will have 1/16 play in the holes. Now to the point. I was going to use a drill bit but don't want to cause any undue stress on my machine so I am thinking I will start out drilling 1/4 inch holes with a drill bit, then switching to a 3/4 center cutting end mill in a collet, then switch over to a 1 1/16" center cutting 6 flute end mill to drill to the final size. I will be using the DRO so hole placement should be very accurate. Does this sound like an acceptable method and better than just using a 1 1/16 drill bit? thanks Paul

true temper
03-06-2015, 09:44 PM
Get an annular cutter, you won't be sorry.

paul463
03-06-2015, 09:48 PM
Get an annular cutter, you won't be sorry.

Yes

Toolguy
03-06-2015, 09:50 PM
Congrats on the Acer mill! That's a very nice machine.

End mills make crappy drills. Just get a 1-1/16 annular cutter to start with. That will sink right through and be done in one shot per hole. The next best thing would be start with a 1/4" drill, go to a 1" drill, then a 1-1/16 reamer. Or you could use a 1" annular cutter, then a 1-1/16 end mill or reamer.

pb57
03-06-2015, 09:54 PM
whats an annular cutter and what do cost True Temper? what is the advantage to what I was going to do? thanks Paul

pb57
03-06-2015, 09:59 PM
Ok thanks, I will have to price it out. That would be great if it will cut the hole in one pass and hopefully be able to cut all 40 holes in the 1" thick material without wearing out. What kind of spindle speed should it be run at? Paul

true temper
03-06-2015, 10:02 PM
Cuts round holes like butter, I smile every time I use one. One example, http://www.ebay.com/itm/1-1-16-X-1-long-M2-HSS-Annular-Cutters-/281280976785?pt=LH_DefaultDomain_0&hash=item417da71791

oldtiffie
03-06-2015, 10:10 PM
https://www.google.com.au/?gws_rd=ssl#q=broach+cutter

http://www.machineryhouse.com.au/D9512

pb57
03-06-2015, 10:29 PM
will a normal 3/4 collet hold the annular cutter or do I need a special holding tool for it? I have looked in Enco and MSC but they show no tool that they fit into. They are recommended for magnetic drills

Lu47Dan
03-06-2015, 10:46 PM
A Champion CT-7 carbide cutter works real well to cut large holes. I have one I have over 100 holes done with it.
Dan.

pb57
03-06-2015, 10:57 PM
Ok I just ordered the Bison 1-1/16 annular cutter off ebay it was only 25 dollars so I hope I can get through all 40 holes with it. Im doubting it however. and hopefully the 3/4 collet will hold it unless there is a better method. earlier today I ordered the 1- 1/16 center cutting end mill because I thought that was the better method than a regular drill bit.

true temper
03-06-2015, 11:20 PM
This would be the best option, http://www.ebay.com/itm/Magnetic-Drill-Arbour-Holder-Mag-Annular-Cutter-Rota-broach-R8-shank-bridge-port-/400772073534 I have used a collet and got by fine. A Weldon end mill holder will not work on annular cutters bigger than 3/4" they are too long. Set screw won't reach. I am going to turn one down so it will work.

Carm
03-07-2015, 07:01 AM
Pb57
I have made these remarks on this forum enough for this disclaimer; I don't own or work for any of the annular makers. But they should pay me for the PR.
Yep, they are great for making holes, especially large, close to size, repeatable holes that are round, ESPECIALLY on low horsepower machinery.
The 3/4 R-8 collet will work but you need to observe a couple things. Since it doesn't have the posi drive screws, don't use power feed. If you spin the collet, its days are over if you can't stop on a dime and let things cool before retracting.
Since the collet doesn't have the ejector/locator pin along with interior coolant flow, you get differential expansion, which at worst, causes the above seizing, or just makes it a PITA to remove the slug. Remember to set the start depth at least slug length above the work.
Put a gob of Crisco in the cutter bore before you plunge. Use a spray bottle at least.
Annulars make nasty uncontrollable birds nests. To avoid that, drill a hole a little less than cutter thickness anywhere in the cutting circle. Also makes slug extraction easy.
HSS SFM of 120 or close works for RPM. 40 holes is a cakewalk.

MrSleepy
03-07-2015, 08:02 AM
The cutters cat be sometimes had cheap on ebay if searched for a bit laterally.

In the UK , the technology was pioneered by the RotaBroach company in Sheffield so search Rota Broach , Rotabroach

In the US (and UK) , Jancy Engineering sold well with their "Slugger" trademark , So search jancy cutters , slugger cutters , Fein Cutters.

Rob

oldtiffie
03-07-2015, 08:16 AM
As the hole positions by the nature of their intended purpose are not really required to be too accurately placed, and if it were me, I'd mark them out and centre punch the hole centres, use a pilot drill to suit the annular cutter and then either hire of buy a good magnetic-based drill for both the pilot and the cutter - and with a good feed of coolant/lubricant.

Do not use a vertical mill as it may cause excessive wear on the mill quill.

A good pedestal drill is the way to go if a magnetic-based drill is not available.

Carm
03-07-2015, 08:43 AM
"Do not use a vertical mill as it may cause excessive wear on the mill quill."

Respectfully disagree Oldtiff. But it is true that you won't wear out what you don't use. An annular needs far less thrust than any solid drill.

Mr.Sleepy, Hougen used Rota-broach as a trade name...was there licensing from UK or did they buy it? Just curious.

Axkiker
03-07-2015, 09:48 AM
What do you plan on using for the ram. I eventually want to do the same so im curious how you are going about this build.

MrSleepy
03-07-2015, 10:11 AM
Mr.Sleepy, Hougen used Rota-broach as a trade name...was there licensing from UK or did they buy it? Just curious.

Hougen Manufacturing were the inventors and patent holders ... and Rotabroach is a trademark for them .. The UK Rotabroach is their UK arm set up in 1975 .

goose
03-07-2015, 10:37 AM
I agree it sounds like a job for a drill press.

Toolguy
03-07-2015, 11:15 AM
"Do not use a vertical mill as it may cause excessive wear on the mill quill." OldTiffie

Sorry Tiffie, but I must respectfully disagree with you on this one. A Bridgeport type mill is the best drill press ever. You have the workpiece firmly clamped and rigidly controlled and make the hole locations with great exactness. Drilling has a concentric axial force going straight up and down the spindle. No problems for the quill. End milling puts a heavy radial load on one side of the quill, yet the mills go for years doing that.

I would suggest to the OP to do one hole with the end mill and one hole with the annular cutter at the beginning and see which you prefer to use. It will be an educational opportunity.

metalmagpie
03-07-2015, 04:04 PM
I have done a lot of work with annular cutters. Be sure to use a cutting fluid. These cutters are expensive to sharpen, so do everything you can to keep them sharp.

I have used them in a 3/4" end mill holder. They cut the holes fine but ejecting the slugs is tough. I agree with the suggestion to use a mag drill. However, if I were going to do that I'd tack your verticals in pairs and cut your holes through both at once so all of your holes line up.

metalmagpie

JRouche
03-07-2015, 04:56 PM
This thing eats!!

http://i1183.photobucket.com/albums/x461/_GLE_/HSM/Enco%20Mill/2_zpsc9543d24.jpg (http://s1183.photobucket.com/user/_GLE_/media/HSM/Enco%20Mill/2_zpsc9543d24.jpg.html)

I have about 50 brand new cutters for it. Didnt have it when I built my 50ton press. I used my el cheapo ryobi 14" drill press. Its the bench model. And a greenlee 1" hole saw. I only had to do 32 holes through 3/8" steel and the holesaw is still scary sharp. JR

http://i1183.photobucket.com/albums/x461/_GLE_/HSM/9f863638-7147-46b0-a372-7932e0bb5a79_zps90n45evw.jpg (http://s1183.photobucket.com/user/_GLE_/media/HSM/9f863638-7147-46b0-a372-7932e0bb5a79_zps90n45evw.jpg.html)

Carm
03-07-2015, 05:10 PM
If anyone does stack their material, be careful to stop and pull the slug after the first hole, or you will have problems.
The typical grind DOES NOT cut the inside through, it leaves a thin burr around the slug. This will spin preventing entry, and if you're asleep possibly breaking the cutter or stripping the rack.
Grinds can be had for stack cutting.

pb57
03-07-2015, 09:09 PM
Thanks for all the replies guys. I have a nice 15 inch Clausing Drill Press that I just restored but I am still going to use my new mill. I think the DRO will simplify things and keep things accurate. My new Acer doesn't have coolant yet and don't know if I will ever install it. I like the idea of Crisco inside the annular cutter but what cutting fluid would be best for this particular application? Ive built 2 presses in the last 25 years and have just drilled the holes in the past. I have always used 6" ID cylinders with a Williams pump with its own reservoir. They were a popular pump for hoists on straight truck boxes. I install a 1-1/2 horse motor and pulley it about 4 to1 and they have worked great and last forever. They put out between 3500 and 4000 psi and that easily computes to 50 ton. I like the power when I need it. Hate the cheap Harbor Freight presses I looked at but im sure they work fine for most garage applications. Plus I like to over build. thanks again Paul

Carm
03-08-2015, 07:29 AM
"...but what cutting fluid would be best for this particular application?"

Any soluble cutting oil. The portables (mag base) have a gravity fed canteen, I have used water in them. On a mill, usually dry (with Crisco) but not production pace.