[4]

Looking for advice on a small (ish) mill

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
Greetings everyone! I'm looking to buy a (relatively) small mill and lathe. I own and run a small atv/motorcycle repair shop. I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts. The lathe would be mostly small stuff, under 3" in diameter. I worked a at a place that manufactured welding equipment, and I had the chance to learn all the machinery there, and I love doing that type of work. I was able to program and run some big Haas mills and lathes. We had a tormac cnc mill that I loved. We had a big ganesh, but never ran it, but I spent a ton of time on a grizzly lathe (8"? 9"?) and a manual grizzly mill (26" wide x 8"? Table).

I have 2 main questions, 1: what do you guys suggest for tools. And 2: does anyone have any they're trying to sell? I can probably only spend up to $1500 on a mill setup right now, unless I wait until like July, then could spend a bit more. And lathe will have to wait until next year. I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it. Also have looked at grizzly 0760 (but just the machine is about $2k delivered with no vise, no collets etc....)

Thoughts?
 

tq60

Brass
Registered
Joined
Jan 11, 2014
Messages
760
Avoid a round column mill.

The work envelope is not so great and you are limited by spindle travel.



Sent from my SAMSUNG-SGH-I337Z using Tapatalk
 

7milesup

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Jan 7, 2016
Messages
387
Take a look at Precision Matthews equipment. http://www.precisionmatthews.com/ Better warranty than Grizzly and far better customer service, although Grizzly still isn't bad.

I agree with tq60, avoid a round column mill.
 

mikey

Active User
H-M Platinum Supporter ($50)
Joined
Dec 20, 2012
Messages
5,541
I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts.

... I can probably only spend up to $1500 on a mill setup right now.

I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it.

Thoughts?
In an ideal world, yes, avoid a round column mill. However, you have a budget of $1500 and your stated goals are not complex.

Crutches, are you sure about the Jet? I know they make a JMD 15 and a JMD 18 and I suspect the mill in question is an 18. If so, it will weigh close to 400# without the stand and has a 3" diameter quill with 5" of travel so it is, in fact, a really good heavy duty drill press. It will flycut quite well and handle most any small motorcycle part. I own an RF-31 which is essentially the same machine and after upgrading the bearings, it has under 0.0001" of spindle run out. I know what this machine can do and other than the issues common with the round column mills, it is quite a capable machine. It may suffice and earn you enough money to upgrade to a knee mill at a later date and I would consider it.

Depending on its condition and tooling, $950 may be high. I would take a dial test indicator and a magnetic stand and check the spindle run out. Run the machine on high speed for about 15 minutes and then check to see what kind of concentricity you can get out of the spindle. If it is the thousandths then that right there is your ammo to get the price down. If those spindle and drive sleeve bearings are stock then I would bet money the runout will be anywhere from 0.001 - 0.003" or more. Tell him that replacement bearings will run about $300.00 and the labor to install them will run close to $150.00. See if he'll take $500-600 instead. You never know. If he plays hardball then just walk away. If he bites then the cost for the drive sleeve bearings will be under $30.00 for the pair. The spindle bearing OEM replacements should be under $150, possibly much less. Angular contact bearings can be pricey but I did mine for about $100.00. Not too bad.

If you are not sure how to check concentricity then say so and we'll tell you how. I believe that in your situation the machine has to earn its keep and for your simple needs, that Jet mill drill would work just fine in my opinion.
 

Mitch Alsup

Active Member
Registered
Joined
Nov 17, 2017
Messages
486
I would use the mill as a few things: heavy duty drill press, fly cutting cylinder heads, as well as general custom fabrication for motorcycle parts.
Don't try to fly cut cylinder heads with a mill weighing less than 1000 pounds (and 2000 pounds is better).

The lathe would be mostly small stuff, under 3" in diameter. I worked a at a place that manufactured welding equipment, and I had the chance to learn all the machinery there, and I love doing that type of work. I was able to program and run some big Haas mills and lathes. We had a tormac cnc mill that I loved. We had a big ganesh, but never ran it, but I spent a ton of time on a grizzly lathe (8"? 9"?) and a manual grizzly mill (26" wide x 8"? Table).
I have the big brother of the 6*26 (as a 8*30 G0730) and love using it (although it's not a Bridgeport....)

I have 2 main questions, 1: what do you guys suggest for tools. And 2: does anyone have any they're trying to sell? I can probably only spend up to $1500 on a mill setup right now, unless I wait until like July, then could spend a bit more. And lathe will have to wait until next year. I'm looking at a jet 16 mill/drill with a round column, but don't love it. He Wants $950 for it. Also have looked at grizzly 0760 (but just the machine is about $2k delivered with no vise, no collets etc....)
Stay away from round column mill/drills.
 

Billh50

Active User
H-M Supporter - Gold Member ($25)
Joined
Jan 26, 2015
Messages
1,922
I don't know why people put down round column mills so much. Sometimes it is all one can afford or fit in the space they have. And if care is taken they will do the job for what the OP is looking to do. I know because that is the type of work I have done on a round column mill with no problems. The only time he will need a larger mill, that I can foresee, is for 4cylinder heads as they will be too long for the travel of the round column mills. As far as fly cutting he should only be taking minimal cuts just to clean the heads.
 

SSage

Active Member
Registered
Joined
Jun 16, 2017
Messages
149
Save up and buy a decent mill. I've seen huge Bridgeports go for a $1000. Just a pain to move and feed them 3ph.

The Precision Matthews Pm727m is priced good for a small gear head unit. I think it's around $1500 new, can't remember. I've been happy with mine, I got the DRO version with the stand. It's better than the Grizzly version imo.

DROpros sells small mills too. With a low budget your better finding one used on Craigslist if you're familiar with the machines and can identify the boat anchors.
 

chips&more

Active User
Registered
Joined
Mar 19, 2014
Messages
2,554
How long are the heads you are going to fly cut??? To properly make a fly cut pass you should start and stop with the cutter past the edges of the head. Sooooo, if you do the math. If you total the length of the head and diameter of the fly cutter. That is approximately the table travel you need. And don’t assume a 48” table travels 48”. It does not! It’s much less!!! Doing a 1 cylinder head may not be a problem on a mid-size mill? But I would carefully check out table travel first...Dave
 
Last edited:

stioc

Active Member
Registered
Joined
Feb 22, 2017
Messages
419
Amazing amounts of work has been done on the round-column mills since the 80s! there's a reason they're still sold and purchased today. Most people that down them usually have no direct experience and simply repeat others giving the same (ill?) advice. But yes, by all means, if you have the funds and you don't care to learn how to keep the z-axis alignment when dealing with short and long tools (that's the biggest and perhaps the only complaint on these) which takes all of 30 secs if you know the technique then buy a square column mill. Otherwise, if you're getting a bunch of tooling etc they can be a great bargain...
 

stioc

Active Member
Registered
Joined
Feb 22, 2017
Messages
419
So I got curious to see what the round-column mills are going for in my area and while they're all over the map ($600-$1500+ depending on what they come with) I particularly found this ad very interesting so I took a screenshot of it to post here. Also on youtube look for user cuppajoe, google Rick Sparber - among others who have had these for many years and have done good work on them. I'm in the process of converting mine to CNC...hopefully soon, if I can just stay focused on one hobby at a time.

RF30CLad.JPG
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
Wow thanks guys. I didn't get emails that I had any responses. This was really nice to come back to. I have a friend who taught me the basics of machining, who I found out has an old Bridgeport. He converted it to a full cnc system, but it's been sitting on a trailer for 4 years. He said every 4 months, he'd go WD40 it, and replace the tarps around it. He Wants to open up his own shop, but can't do it in the next several years, so he's been saving it. But he offered to let it live in my shop, so it has a purpose. I'd get a rotary phase converter to give it 3ph. But the table is pretty rusty. He said he doesnt blame me if I don't want to mess with it at all. But dang... I'd only be paying for Transportation costs, de-rusting and the converter. He mentioned we should convert it back to manual, but doesn't have the hardware.

I need to be able to bore these atv cylinders! I've had 3 come into the shop in the last week that I've shipped off to get bored. And the shop called and let me know they had an accident, and ruined a cylinder. Ah! So they're paying to sleeve it, then re-bore it. What machines do you guys have that you're looking to sell?
 

ACHiPo

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Feb 2, 2017
Messages
645
Congrats! Sounds like a plan! Might want to go the VFD route rather than rotary converter as it gives you easy speed control.

Pics or it didn’t happen!
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
How long are the heads you are going to fly cut???

Most of the heads we would do are single cylinder, but I do quite a few RZRs as well. Those heads are maybe 10" across.

And ACHiPo, we had talked about going VFD, but he said you can only get something like 70-80 % of the capacity of the motor with those, as opposed to the rotary, you can get more. Thoughts? And here are pictures. What do you guys think? Worth it? How hard would it be to convert it back to manual?
3794.jpeg

3796.jpeg

3798.jpeg

3800.jpeg

3802.jpeg

3804.jpeg

3807.jpeg

3809.jpeg

3811.jpeg

3813.jpeg

3815.jpeg
 

JimDawson

Global Moderator
Staff member
H-M Platinum Supporter ($50)
Joined
Feb 8, 2014
Messages
7,839
That looks like a project. :) Never seen a BP like that before. Has a different table and knee than I have ever seen. Looks like an Ericson BT30 QC spindle.
 

ACHiPo

H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Joined
Feb 2, 2017
Messages
645
Thoughts? And here are pictures. What do you guys think? Worth it? How hard would it be to convert it back to manual?
Well Crutches, I'd say you've got a bit more than a small mill there! That thing is a beast! If it runs and the axes move, it seems like it would be worth some TLC especially if you get to hang onto it for a while. Nice score.

It's definitely massive enough to do heads (and V-8 blocks!).

Regarding the VFD that motor may be big enough to be problematic for a VFD, although if it isn't, I wouldn't be terribly concerned about losing 20% power.
 

P T Schram

Active Member
Registered
Joined
Mar 31, 2015
Messages
179
Looks like a Bridgeport Series II maybe

One of the few that are really worth what everybody goes nuts over

That is a much heavier machine than your typical vertical universal machine and will serve you well for your intended purpose. The "standard" Bridgeport mill is much too light IMO and tends to chatter, but not their bigger machines. There was a series of early NC mills that were about as rigid as one could imagine but being early NC, many were scrapped when the CNC became standard-I used to know where there were two, and I was offered one if I helped the owner convert the other to more modern electronics

You've done well young Jedi, and I hope,for your sake it lives in your shop a good long time
 

JimDawson

Global Moderator
Staff member
H-M Platinum Supporter ($50)
Joined
Feb 8, 2014
Messages
7,839
I don't think that mill was ever manual, and if it was converted, then someone went through a heck of a lot of work machining castings to install the round rails. That knee and saddle are nothing like anything I have ever seen on a BP, but looks like a factory instalation. It could be operated manually simply by hanging some handwheels on the axes.

Regarding the VFD that motor may be big enough to be problematic for a VFD, although if it isn't, I wouldn't be terribly concerned about losing 20% power.
That looks like a standard 2HP BP spindle motor, but could be a 3HP. In either case would be no problem for a VFD. And no, you won't lose 20% power with a VFD, you will get full power with a better torque curve. If you were using a static phase converter, then you would lose about 33% because the motor is only running on single phase
 

P T Schram

Active Member
Registered
Joined
Mar 31, 2015
Messages
179
I don't think that mill was ever manual, and if it was converted, then someone went through a heck of a lot of work machining castings to install the round rails. That knee and saddle are nothing like anything I have ever seen on a BP, but looks like a factory instalation. It could be operated manually simply by hanging some handwheels on the axes.
That is Bridgeport's first entre into the world of NC and I think you'll have a LOT more work trying to put handwheels on it than you'd expect and you'd be disappointed in the performance.

With new electronics it can be a Helluva machine
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
Alright guys, it's been a journey... I bought a rottler boring bar on ebay shortly after making this post last year. I've been boring atv cylinders with it, and it's worked, but I've needed a mill to do other things. So I bought a 50's round ram Bridgeport in ebay that had a J-head installed. Long story short: freight companies were a nightmare to deal with, and kept having logistic errors, which caused the seller to get mad, and repost it. So I lost it. Ill get my money back, but don't have the mill. I was telling this friend of mine about it, and he said. "well that Bridgeport is still sitting on the trailer. I'd like to not have to worry about it. It's yours. Take it for free. Clean it up and use it and it's yours."

So he said it's a Bridgeport series 1, that the company he worked for upgraded. It has full linear ball screws on the Y that are tight, can do 0.0005" well. He said we should ditch the cnc, convert it back to manual. They put a 54" table on it.

So I'm going to go up (about 2 hours away) and we will see about getting it onto my trailer. So here's my questions:

Advice... What are the first things you want to say about it? (or about how much you hate me )

Where do I start? Soak it in wd40? Take the table off?

Just sit and drool over it?

Where can I source hand cranks for it? Besides ebay?

Thanks! I'm excited for the journey.
 

matthewsx

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jan 2, 2019
Messages
430
Well, the price is right. If you have the space jump on it.

Don't know if I would bother converting it to manual, you'll get better cuts with the servo drives and providing they work it should cost a lot less than finding/fabing all the stuff to change it. The control and drivers have come way down in cost since that unit was built and LinuxCNC is free.

Disclaimer, I'm just getting started with CNC but I am a computer guy. I also used to own a small engine shop and did racing kart engines so I know what kind of work you're doing. I suspect a lot of folks think CNC is going to be too complicated, or the time to do a set-up will be a lot more than just putting their work in the vise and cranking away with it. Your buddy might be one of those, or he might really know why this particular machine would be better manual. However, I'm gonna bet it will take a lot less time, effort, and $$$ to update the electronics than to try and convert it to manual. Most people go the other way for a reason.

There are lots of folks on here and CNCZone that will be helpful and with a machine like that you can even ask questions on Practical Machinist. Off the top of my head you'll need a control board (I bought a 5 axis for $20), servo drivers, and an older PC besides cleaning it up of course. I would figure out what the servos are and get one driver to test them with first. Once you get it running you can use a pennant to control it without having to actually write a program for what you need to do.

BTW, there are much better ways to remove rust than WD40 but that table doesn't look too bad. Some scotch brite and mineral spirits might be all you need.

Congrats on your score, keep in touch and if you're looking for a small engine dyno let me know.

Cheers,

John
 

ThinWoodsman

Active Member
Registered
Joined
Jul 8, 2018
Messages
448
Where can I source hand cranks for it? Besides ebay?
Eisen has them:
handle
handwheel

Also, for the rust, paper towels soaked in evaporust and held in place with magnets make a great first pass. When the paper towel dries out, go in with the scotchbrite and mineral spirits.
 
Last edited:

richl

Active User
Registered
Joined
Mar 2, 2013
Messages
894
Mcmaster is a good source for many things also. Might be something to bookmark. Nice "smallish" mill lol wish mine was that small :grin:
 

P T Schram

Active Member
Registered
Joined
Mar 31, 2015
Messages
179
Everything I said at first still stands.

Buy it, convert to modern CNC controls, etc and make chips.

I'm jealous over your Rottller, I recently got a Kwik-Way but haven't had a chance to get it fired up yet.
 

hman

Active User
H-M Platinum Supporter ($50)
Joined
Feb 17, 2013
Messages
2,282
Regarding conversion to manual ... just remember that, unlike Acme lead screws, ball screws can be back-driven, often with relatively low force. So be sure to lock down the unused axes when milling. Otherwise, your table might start wandering all over the place unexpectedly.

Other than that minor caution - Congratulations!
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
I'm jealous over your Rottller, I recently got a Kwik-Way but haven't had a chance to get it fired up yet.
That rottler was the first piece of machinery I bought (besides a forklift haha). It is awesome to use, and produces an amazing cylinder. But selling it will fund tooling/upgrades for this new BP. I had someone offer $1k for it on ebay. I counter offered at $1100, but they didn't accept it. I started to take it out of commission today so I can crate it up to ship it.
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
So I'm hoping to go up this weekend and get this thing somehow. When I'm actually near it, I'll take pics of all the motors and stuff and post. I signed for cnczone, but holy!! There's a lot of places to post. Didn't know where to start. General cnc?

I'll post pics of what this thing is and maybe someone can point a finger in the general direction, then I'll research like crazy and probably start spending at that point too. Haha.
 

matthewsx

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jan 2, 2019
Messages
430
So I'm hoping to go up this weekend and get this thing somehow. When I'm actually near it, I'll take pics of all the motors and stuff and post. I signed for cnczone, but holy!! There's a lot of places to post. Didn't know where to start. General cnc?

I'll post pics of what this thing is and maybe someone can point a finger in the general direction, then I'll research like crazy and probably start spending at that point too. Haha.
Take your time figuring out how to move it, if your buddy already has it on a trailer it might be worth putting new tires and bearings on his rather than trying to transfer it without the proper forklift or crane to pick it up. Chain & strap it down good and take the journey slow with lots of stops to make sure everything is tight. Also make sure the boards/skid underneath are in good shape, you don't want that giving out on the highway. Be EXTRA CAREFUL, that thing weighs more than either of you think;)

As for CNCZone you can post in the general area and the moderators will move your post if needed. Certainly the first post from someone getting a new machine is always welcome. Posts with pictures of moving stuff is even better.

Cheers,

John
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
Take your time figuring out how to move it, if your buddy already has it on a trailer it might be worth putting new tires and bearings on his rather than trying to transfer it without the proper forklift or crane to pick it up. Chain & strap it down good and take the journey slow with lots of stops to make sure everything is tight. Also make sure the boards/skid underneath are in good shape, you don't want that giving out on the highway. Be EXTRA CAREFUL, that thing weighs more than either of you think;)

As for CNCZone you can post in the general area and the moderators will move your post if needed. Certainly the first post from someone getting a new machine is always welcome. Posts with pictures of moving stuff is even better.

Cheers,

John
Thanks for the advice! I'll hopefully have updates this week on what happens. I'll update.
 

Crutches56

Active Member
Registered
Joined
Jan 1, 2018
Messages
24
So I came up today and saw the mill for the first time in person. She's gorgeous. Really rough around the edges.... But I can tell she's got sweet spirit. . Here are some current pics. The rust on the table is far less than I thought. I was curious enough to try and move things. The x axis motor has a shaft you can grab onto, and we were able to spin it and move the whole table way easy. Only moved it back and forth about 0.060" each way. I'll clean it good before I do too much. The knee won't go up or down. The crank spins almost a full turn then binds, so hopefully my gib isn't ultra stuck/broken. I didn't check anything else beyond that mechanically. The spindle had a spindle wizard built in, but I might try and convert that. Have to research that a bit. It came with an old desktop computer and a stand that bolts onto the machine to hold it all. I'll be converting to just a laptop. Haha. The control box on the back...... I need opinions. Do I try and get it to work, or do I just scrap that and replace it with something more current? I have pics of the whole machine, the main motor, the stepper motor tag (3 identical motors for X, Y, and Z (not knee, that's still manual, but I want to get a power feed).

We're taking his beat up trailer about 5 miles to a equipment rental center tomorrow morning. I talked to them, they said for $50, I can use forklift to move it. So we'll lift it up (my buddy has moved a lot of machines over the years), we'll drive out from under it. Then back my trailer under it, and set it down and get her secure.

Advice? Thoughts? I'll post more pics and Info as it comes.
 

Attachments

matthewsx

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jan 2, 2019
Messages
430
For moving make sure to rotate the head and block it against the table. Go slow and take it easy, more straps and chains than you think you need, others probably have more/better advice.

As for the control box, you will probably end up tearing it all out but it's worth trying it as-is to see what it'll do if you can get the correct power to it. There may be parts you can re-use so don't throw anything away of course. If it were mine I would make a comprehensive plan on what parts are needed and the required specs first. Then you can look for used/surplus pieces that are suitable, you will have plenty of time while you clean and inspect the mechanical aspect.

Looks like a beauty, take your time to get it right and you will have a machine that will last a lifetime and you won't outgrow:cool:

John
 
[5] [7]
Top