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Calling on all the machinists!


phoenix2013

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Need to machine the raw castings I buy.

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The jigs have been designed an tried in a machine shop and small quantity of production parts were manufactured.

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Next step to reduce the cost is to "bring it in-house", I always had a soft spot for "hands on" as many of my friends can attest to.

I don't think I have a need or too much space for nice "used" one Bridgeport./ What about one of these mill/drills such as this one. http://www.travers.com/87-115-929?Category=UserSearch=87-115-929&gclid=Cj0KEQjw4fCqBRDM1ZKhk5jfo6IBEiQAZQ97OI8OYUH-HEWoKNmrTABuuaT6q9DDlPo_R8SLKYq-cIgaAgoL8P8HAQ

Any brands or models better than others? Any to stay away from? I also noticed some are available with readouts for extra dough. Will need to bore the 2 inch hole where the slug is and mill couple of flats on each jaw.

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Henry,

 

Steve is very much correct regarding the very limited capability of the small Mill / Drill Imported Combo-machines .

 

The machine you link to is actually a slightly modified drill press with the Jacobs taper quill bored out and machined to a R8 configuration and then a basic draw bar installed from the top of the quill. The real problem is that at the end of the day these machines at the core are still a Drill press NOT a Mill.......they may accept a R8 tool but the Mass and stiff structure of a real Mill are missing.

 

Steve is also correct in that a common 42" Bridgeport is fairly light machine for machining castings. As you may recall steel and Iron castings have a very tough HEA (Heat Effected Area) that is the "Casting Skin" that is very tough and often pretty hard from casting cooling and others factors from the casting process (This Tuff outer skin is best shown in engine cylinder liners that are cast and then machined to utilize the very long wear qualities that we see in our 1,000,000 mile engines).

 

The Hard and Tuff skin of Steel and Iron casting makes a pretty tough work for the "normal" 42" Bridgeport Mill. Bridgeport and a lot of other companies make bigger machines that would handle the casting job better but these machines tend to have National Taper spindles that are much more stable than any R8 tool ( and more costly).

 

I have had machine shop equipment all of my adult life and you can get a lot of work out of a quality R8 mill........However, when the materials get tuff and the slots, surfaces and holes start getting larger the R8 tooling starts to become marginal quickly and in marginal always means SLOW machining and lesser quality finishes.

 

I might have a few suggestions that you might consider if you desire to PM me.

 

Best regards,

 

Dollytrolley

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Henry,

 

Steve is very much correct regarding the very limited capability of the small Mill / Drill Imported Combo-machines .

 

The machine you link to is actually a slightly modified drill press with the Jacobs taper quill bored out and machined to a R8 configuration and then a basic draw bar installed from the top of the quill. The real problem is that at the end of the day these machines at the core are still a Drill press NOT a Mill.......they may accept a R8 tool but the Mass and stiff structure of a real Mill are missing.

 

Steve is also correct in that a common 42" Bridgeport is fairly light machine for machining castings. As you may recall steel and Iron castings have a very tough HEA (Heat Effected Area) that is the "Casting Skin" that is very tough and often pretty hard from casting cooling and others factors from the casting process (This Tuff outer skin is best shown in engine cylinder liners that are cast and then machined to utilize the very long wear qualities that we see in our 1,000,000 mile engines).

 

The Hard and Tuff skin of Steel and Iron casting makes a pretty tough work for the "normal" 42" Bridgeport Mill. Bridgeport and a lot of other companies make bigger machines that would handle the casting job better but these machines tend to have National Taper spindles that are much more stable than any R8 tool ( and more costly).

 

I have had machine shop equipment all of my adult life and you can get a lot of work out of a quality R8 mill........However, when the materials get tuff and the slots, surfaces and holes start getting larger the R8 tooling starts to become marginal quickly and in marginal always means SLOW machining and lesser quality finishes.

 

I might have a few suggestions that you might consider if you desire to PM me.

 

Best regards,

 

Dollytrolley

 

PM sent

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Phoenix:

 

I have a table top mill/drill from Asia.

 

If I had to do it over again, I would have bought a good used Bridgeport.

 

Here are the problems I encountered.

 

1. The upright column was not perpendicular to the bed. I had to sweep the bed with a dial indicator and add shims under the flange where the column bolted to the bed to get the column perpendicular.

 

2. I cannot angle the head. The head only has one setting which is 90 degrees to the bed.

 

3. I had to add a power feed in X and Z axis. None was available so I had to design and build them.

 

4. The Z axis is "sloppy" with no way to adjust out the play. As such, I cannot use a boring head (as shown in your photo).

 

5. Since it does not have a "knee," I have limited range of Z axis adjustment. So, if I am spot drilling, drilling and tapping a hole, I have to make sure all tools will work with the range of motion of the z axis.

 

6. To adjust the z axis requires loosening the screws that clamp the head to the column. When this is done, then the alignment is lost. The fix is to use a laser beam, focused on a vertical line on a wall about 20 feet away. Then when you loosen the head (to lower or raise the head) you have to adjust the head (before tightening it) to get the laser back on the target on the wall.

 

With that said, it has served me well on many projects, but it ain't no Bridgeport.

 

And there were (I am outdated) other options to a Bridgeport. As I recall there was a mill called a Lagun [spelling?].

 

Whatever you buy, get one that has power feed (on x and z axis), digital readouts on all x, y and z axis and as much tooling that you can get. R8 spindle used to be the standard, but I am outdated and there may be better options today. Also, get as many end mills, end mill holders and collets that you can get. How about a rotary table and indexing head and a vise. The point is that the tooling is really expensive! It will "nickel an dime" you to death. So, look for a mill that has as much tooling as possible.

 

Get a variable speed spindle motor. Changing belts gets old really quickly.

 

Check the table top for "damage" like when an end mill accidentally cut the table. If the table is "pristine" it is reasonably safe to assume that the machine was well cared for, as opposed to a machine that has table scars all over it.

 

Lastly, check out the CNC milling machines. You may get a great deal on a used machine that can be run manually and is programable.

 

Too bad you are not on the West Coast. One of my friends has done machinery repair for about 30 years. He goes to machinery auctions and could get you a sweet deal on a good machine.

 

Jim

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..................... He goes to machinery auctions and could get you a sweet deal on a good machine.

 

Jim

 

Jim, not out of the question, I have accounts with several shipping/trucking companies dealing with 750 pound hitches. I am trying to do a very limited thing on a repetitive basis, I'll send you a PM explaining it (tomorrow, it's almost midnight here).

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IMO, a higher powered, geared drive, drill mill with an R8 spindle and as large diameter post as you can get, will fit the bill for what you describe.

 

An R8 collet system will clean 2" holes with no issues. Especially in castings. I would make sure you have a quality tool cooling system and a coolant catch tray. Imports will usually slide on a gib system for the table. Make sure the brand you choose has a good table lock system to hold the table where you set it. The table screws will not be a ball screw setup so there will be some slack, but once jigged for repetition, it can work fine.

 

How much measure tolerance do you have with these parts?

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