Seeking input on my first milling machine

[hoz53]

The head on the PM-25MV I ordered does swivel. Though I don't plan on using that function much for what I am trying to achieve right now. I purchased the Edge technology shank mount indicator arm and a swiss dovetail dial indicator to swing out wider on the table if required. Also got the Edge vise jaw squaring tool to help true up both ends of the vise jaws simultaneously. And of course a T-slot mounted vise stop for duplicating parts or return to zero when swiveling the vise. Basically trying to cover all options to see what I like best.

Already spent another $700+ in tooling and indicators.... Think I have everything to get me started anyhow. Will gradually acquire other tooling when I find it is needed. Don't want to buy too much right off the bat or I may end up wasting money on things I won't use

you need the head to swivel front to back and side to side to be able to tram the head to the table

 

[jkohler]

I believe on that one it has to be shimmed to correct any nod the head may have to the table.

 

[hoz53]

What type of mill? Some of the basic ones have fixed quills/heads and can not be swung on an angle so tramming isn't a viable operation. Wear in the gibs can be a factor. You could be dead nuts perpendicular in the center of the table and off on the ends.
Having said that, a five inch spread between the indicators is less than what I use with one indicator. I go for five or six inches form the quill centerline and lay a ground parallel on the table.

i just stick an indicator in a collet and run the table back and forth the length of its travel to tram the table. Do the same for the vise. I know thats a time consuming method but wont that work? ive never had to deal with a table that wasnt flat. i lay a piece of ground stock on it like you say to check to start with.

 

[hoz53]

I believe on that one it has to be shimmed to correct any nod the head may have to the table.

thats wat i think to

 

[Ledd Slinger]

i just stick an indicator in a collet and run the table back and forth the length of its travel to tram the table. Do the same for the vise. I know thats a time consuming method but wont that work? ive never had to deal with a table that wasnt flat. i lay a piece of ground stock on it like you say to check to start with.

Just check x and y axis then check square at different points of travel. The head on the PM-25MV doesn't "swing" or move "in and out", but it does "tilt" which can be used to correct square on the X axis.

For Y axis squaring, I've been reading that you place very thin shims under the front or rear of the base and the natural counterweight of the mill head and table will shift. Might be other ways to adjust Y axis. I'm just getting into researching that part of tramming with this particular mill. I now its important to have the mill on a level surface to start with.

Watched a video of fly cutting the surface of a long wide aluminum block after tramming the table on a PM-25MV. The travel was extremely precise and uniform. Both overlapping cuts were exactly the same depth for the whole length of the block which resulted in a perfectly smooth finish. Hopefully mine will be the same

 

[hoz53]

Yeah that's my plan. Just check x and y axis then check square at different points of travel. The head on the PM-25MV doesn't "swing" or move "in and out", but it does "tilt" which can be used to correct square on the X axis.

For Y axis squaring, I've been reading that you place very thin shims under the front or rear of the base and the natural counterweight of the mill head and table will shift. Might be other ways to adjust Y axis. I'm just getting into researching that part of tramming with this particular mill. I now its important to have the mill on a level surface to start with.

Watched a video of fly cutting the surface of a long aluminum block after tramming the table on a PM-25MV. The travel was extremely precise and uniform. Both overlapping cuts were exactly the same depth for the whole length of the block which reaulted in a perfectly smooth finish. Hopefully mine will be the same

need to shim y axis by putting shims between the column and base. it will probably take a few attempts to get it the way you want it. im thinking of one where the column sits on top of the base. yours might have the column bolted to the back of the base in which case youd still have to shim between column and base.

 

[Ledd Slinger]

need to shim y axis by putting shims between the column and base. it will probably take a few attempts to get it the way you want it. im thinking of one where the column sits on top of the base. yours might have the column bolted to the back of the base in which case youd still have to shim between column and base.

Thanks. That's definitely a better idea. I was referencing a video I watched for adjusting Y axis on a Grizzly machine. My fault for not remembering the columns are different. The Grizzly column has a pretty piss poor method of attachment. I forgot that the PM-25MV has a sturdy flat column bottom that bolts onto the base. That was actually one of the major features I liked about it more than the Chinese machines. Much more robust for sure, and thanks to your comment, I realize it also allows for a lot of extra adjustability with shimming. I have a bunch of fine shims in .001" graduations. Could even pick up some cheap gap gauges and take them apart to use for precise shimming.

Here's a picture of how the PM-25MV column is attached to the base.

vs. a picture of the way Grizzly G0704 and other Chinese machines attach the column to the base.




I'm no machining tool expert by a long shot, but it only takes a very small amount of common sense to notice which attachment method of the column is better

 

[Dusty Stevens]

I dont think it makes a difference with the load those machines are designed to do. That connection is plenty strong for a tabletop mill

 

[Ledd Slinger]

I dont think it makes a difference with the load those machines are designed to do. That connection is plenty strong for a tabletop mill

All design features matter to me when I'm the one spending the money. I try to leave no stone unturned when conducting research. Some design features may in fact be less significant than others, but I pay close attention to all of them nonetheless.

Let's imagine the mill gets tipped over accidentally when moving it from point A to B...Would these design differences matter then? I definitely think so. Which one has a better chance of surviving the impact? To me the answer is obvious

Why settle for "good enough" when you can have a sturdier design at a similar price point?

 

[shortgrass]

i just stick an indicator in a collet and run the table back and forth the length of its travel to tram the table. Do the same for the vise. I know thats a time consuming method but wont that work? ive never had to deal with a table that wasnt flat. i lay a piece of ground stock on it like you say to check to start with.

A novice mistake that won't work. You would be checking just the spot under the quill. I looked at the specs on this 'machine' and the head will tilt to the right or left 90*. If you have an square end mill the bottom of that end mill (the cutting end) should be parallel to the table. By reaching out with an indicator to the right and to the left you can see if this parallel condition exists and how much to move the head to correct it if it does not. Another method is to lower the quill all the way and place an indicator on a magnetic base to the table with the indicator against the outside of the quill, then raise and lower the table (the knee).

 

[Ledd Slinger]

A novice mistake that won't work. You would be checking just the spot under the quill. I looked at the specs on this 'machine' and the head will tilt to the right or left 90*. If you have an square end mill the bottom of that end mill (the cutting end) should be parallel to the table. By reaching out with an indicator to the right and to the left you can see if this parallel condition exists and how much to move the head to correct it if it does not. Another method is to lower the quill all the way and place an indicator on a magnetic base to the table with the indicator against the outside of the quill, then raise and lower the table (the knee). The quill needs to be 90* to the table.

Thanks for that input. I now understand the error in the referenced hoz53 tramming method. If the table is perfectly flat but traveling at an angle, it would maintain equal distance from the center of the spindle giving false indication of square. It could even be at a 45 degree angle to the spindle and as long as it is traveling in a straight line, the needle on a single indicator centered on the spindle wouldn't move.

 

[shortgrass]

For the same money, you could have bought a smallish knee mill which would be much stouter. I can move a mill with a 10 x 50 table around with a 5' pry bar and 4 or 5 pieces of 2'' pipe. I don't need a fork lift, and I'm considered and old man who has had back surgery.

 

[fguffey]

Been looking at some of the more affordable models

Affordable? How much does an affordable mill cost? I come across mills and lathes that I believe are bargains and underpriced.

F. Guffey

 

[Ledd Slinger]

For the same money, you could have bought a smallish knee mill which would be much stouter. I can move a mill with a 10 x 50 table around with a 5' pry bar and 4 or 5 pieces of 2'' pipe. I don't need a fork lift, and I'm considered and old man who has had back surgery.

Although I talk about price points, the decision wasn't based on price or budget. My decision was based on my current needs and garage layout. Price points are only mentioned as a reference to other similarly designed machines with the features I am looking for. I have two long and very sturdy workbenches in my shop area already set up with all kinds of reloading equipment and presses, vises, table sander, bench grinder, air compressor, tool chests, rifle cleaning/work station, etc... Not really any room to be adding large floor machines without pissing off the wife This mill will sit on the bench where my drill press resides. The drill press will either be given to someone who needs it or find a spot on the shelf in the local pawn shop.

If I ever move again, top priority on a new place is a large heated shop, or at least an area on the land where one can be built. If my needs have changed once I have the extra space, I may look into a large Bridgeport mill and a nice lathe to start chambering my own barrels. If I still like the small mill, I will keep it for the smaller projects and perhaps convert it to CNC with a larger 3 phase motor and VFD. But right now, the PM-25MV has every feature I want and need.

 

[sdean]

It's the operator. All Gordy Gritters has is a little Grizzly mill. He does good enough work.

 

[hoz53]

A novice mistake that won't work. You would be checking just the spot under the quill. I looked at the specs on this 'machine' and the head will tilt to the right or left 90*. If you have an square end mill the bottom of that end mill (the cutting end) should be parallel to the table. By reaching out with an indicator to the right and to the left you can see if this parallel condition exists and how much to move the head to correct it if it does not. Another method is to lower the quill all the way and place an indicator on a magnetic base to the table with the indicator against the outside of the quill, then raise and lower the table (the knee).

ok thanks for the input. i would be checking a spot under the quill for the whole length of table travel. thats the same as reaching out to the right or left. in fact its reaching out alot farther then 5 or 6 inches and so should increase accuracy. however i agree it isnt checking the rest of the table. can check the Y back and forth the same way. can do the same checks several different spots on the table which will tell me if the table is flat. it takes more time than most want to spend.

 

[Cloudrepair]

Ok, tramming the spindle to the table.....

My plan is to buy the Edge Pro Tram System with dual indicators. Is this the way to go or would you fellas recommend something else?

http://www.edgetechnologyproducts.com/pro-tram-system-01-000-10-000-09-000/

I know there's other ways using a single dial indicator on a single arm. Just seems the Edge with dual indicators would be faster and more convenient.

I got one about 10-12 years ago and like it although for the 150 I paid I like the two I made better.
Plus mine are more accurate.
I have made a few different indicator holders that cover all I need and some can be extended as far as needed( within reason) and the one that fits in a .750 holder will reach both ends of the table and then some

 

[shortgrass]

ok thanks for the input. i would be checking a spot under the quill for the whole length of table travel. thats the same as reaching out to the right or left. in fact its reaching out alot farther then 5 or 6 inches and so should increase accuracy. however i agree it isnt checking the rest of the table. can check the Y back and forth the same way. can do the same checks several different spots on the table which will tell me if the table is flat. it takes more time than most want to spend.

The discussion is about 'squaring up' the tilt of the head, not flatness of the table. If the head has a tilt, it is NOT the same. The table on any decent mill is a ground surface, produced on a precision grinder. Think whatever you want, but in my 40+yrs of machining experience your method tells me absolutely nothing, only that you are measuring one point. The point is to tram the head to the table, so that the quill is an exact 90* to the table.

 

[Cloudrepair]

Although I talk about price points, the decision wasn't based on price or budget. My decision was based on my current needs and garage layout. Price points are only mentioned as a reference to other similarly designed machines with the features I am looking for. I have two long and very sturdy workbenches in my shop area already set up with all kinds of reloading equipment and presses, vises, table sander, bench grinder, air compressor, tool chests, rifle cleaning/work station, etc... Not really any room to be adding large floor machines without pissing off the wife This mill will sit on the bench where my drill press resides. The drill press will either be given to someone who needs it or find a spot on the shelf in the local pawn shop.

If I ever move again, top priority on a new place is a large heated shop, or at least an area on the land where one can be built. If my needs have changed once I have the extra space, I may look into a large Bridgeport mill and a nice lathe to start chambering my own barrels. If I still like the small mill, I will keep it for the smaller projects and perhaps convert it to CNC with a larger 3 phase motor and VFD. But right now, the PM-25MV has every feature I want and need.

If your getting a mill I thought you already had a lathe.
A lathe was my first big purchase.
You know what they say a lathe is the only machine that can reproduce itself.

 

[Ledd Slinger]

If your getting a mill I thought you already had a lathe.
A lathe was my first big purchase.
You know what they say a lathe is the only machine that can reproduce itself.

I've looked at lathes. But for that machine I will not compromise size and/or quality since my main intended use will be rifle barrels. It would have to be extremely precise and accommodate barrel lengths up to 30". I don't have the real estate in the garage for that right now.

My purposes for the mill right now are smaller parts and rifle stocks with softer materials like aluminum, wood, and delrin acetal. The smaller mill should do everything I need without any issues.