Options On Purchasing New Mill

Pmedic828

Pmedic828

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Finally saved enough money (maybe) to purchase a new milling machine - I now have a 3 in 1 machine and the lathe is fine but when milling, the quill extension causes deflection. Now for the 64 dollar question.
I am looking at a Grizzly 0796 or a Grizzly 0678 - I have limited space in my shop and cannot use 3 phase power - only 220v single phase. This is a hobby for me and do not intend on using this commercially. I am also recently retired and self taught if this helps. I have many questions listed below and I thought that you maybe more experienced and help me decide.
1) Quill travel - one has 3 1/2 and the other is 5 inches - one is 1 1/2 hp and other is 3 hp.
2) One has 8 step pulley system like Bridgeport and other is single pulley with VFD built in
By the time I purchase a DRO and a Power Feed for the smaller mill, the price is about the same.

Is the 5 inch quill travel better or can you get by with 3 1/2? Is variable speed better - I didn't do any calculations yet but use hardness RPM = (3.82 x SFM) / D - due to cost, I use only 3/8 and 1/2 end mills and have a 1 1/2 face mill and homemade slot cutter. Will I have enough choice with a step pulley. I know that variable speed is probably better, but cost is a great factor - is it better to put money into somewhat larger machine (or a cheaper price) or elect to get variable speed? This is something that cannot be changed easily except to get a VFD.
I really only have space for 8 X 30 and you can always use a bigger machine but .... I will have to disassemble the larger machine because I only have a 74 inch opening to get it into the workshop. The weight I can move with a tractor with a bucket except for getting it into the workshop. Decisions, decisions.... maybe I was blessed without money so I wouldn't have to worry about these things.
Any help would be appreciated - understand to purchase as large a machine as I can but I really don't want to get into overkill and price is important. Your Thoughts Please......
 
These are two different classes of mill: one is 1000 pounds and the other is 2500. Obviously the bigger and heavier mill will be able to do more.

I have a the G0678 and it's fine for what it is, but I bought it because I don't have room for anything larger. If you have the space and cash, buy the bigger mill.
 
I don't own a knee mill but like most of us, I would love to own one. If I were in your shoes I would look at the Precision Matthews line of mills. I understand the space constraints and all but if I had room for a knee mill I would look hard at the PM-935 - hardened and ground table and ways and many other better features than the Grizz line. Cost is nearly the same as the G0796. I would live without a DRO to have the 935 and add it on later as I am able.

If I had this decision to make I would call Matt and talk it over before making a decision.
 
The larger machine is, well, twice the machine:) Comes with a power feed and a DRO!

As far as space and getting it into your shop, I moved a 9x49 machine exactly like it through a standard 36 inch door without disassembling the machine. I did take the door off of the hinges to get it out of the way. Not sure what you mean by ''only have space for 8x30''. Is that the size machine that would fit in your shop? If that's the case then the discussion is over.;)

Speeds: I spend years using change belt machines in both tool & die and general use and found them to be adequate.

I agree with the comments above regarding the PM machines.
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checked with PM and with shipping, single phase, and light, cost is over 2k more - that puts it out of the park - I just don't want to purchase something that would be too small but i only have 73 inches in height to get the machine thru. I guess that if I purchase the large machine, I will have to separate the ram from the base and move them separately, then reassemble - does anyone know if that machine can be separated by the ram or motor removed without a great hassle to reassemble - I am all by myself and in late 60's and cant lift too much without help. Thanks everyone
 
The machines are shipped with the head rotated upside down. So only about 60 inches tall. You have to rotate to the working position on commissioning. This is accomplished by loosening the 4 attaching nuts and using the rotation screw to rotate. To remove the head, remove the 4 attaching nuts and slide the head off forward. An engine hoist or other lifting means is required.

The motor on the change belt machine is very easy to remove. Disconnect the wiring, remove the two attaching bolts, and lift the motor out. It weighs about 90 lbs.
 
Look into a used 7x27, 8x32, or 8x36" Burke Millrite. It is basically a 2/3 size Bridgeport, and more stout than any bench top mill. Weighs about 1400-1500 pounds, depending on options. Depending on where you live (don't know the market in La.), they generally go for about $1-2 K in ready to use condition, and often come with some tooling. Solid, made in USA machines. With the head upside down it is well under 72" high.
 
I would be more inclined to go with a 9x42" knee if you can fit it in, but the weight and size may be an issue. There have been some issues with the QC on the G0695 mill, which is very similar to the GO678. Both of these mills have a cross Y travel of only 7 3/4", and you will probably loose at least another inch if you add a DRO scale. That is very limiting, I sold my bench top mill which had a little over 8" with a scale, and still was a problem , especially after throwing a larger vise on the table. Grizzly G0796 is not a bad package deal, the PM935TS is less, but add a Sino DRO and a power feed, a little more than the G0796. The quality would be better and it is a little more manageable size wise. If you bought a 3 phase mill, you could add a VFD for about $200-$250 if you wanted to go that route. The quill travel, really depends on what you are doing, but 5" would be nice.

http://www.hobby-machinist.com/thre...ion-issues-i-need-guidance.45388/#post-386888
 
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