Lagun FT1 as a CNC Beginning?

[D. Kent]

Hello friends.

I have found a decently priced Lagun FT1 that appears in good shape with some tooling, but it is completely manual. I'm curious if there is anyone on here that is familiar with upgrading to 3 Axis on a manual mill and if so, how the Lagun fairs to other brands. From what I'm reading, they are nice mills, decent size for the garage, and just curious if this is a good candidate for future upgrades or do I hold out for a different model (FVT) or brand that has has more servo options, like a Bridgeport? If I had the money, I'd simply by one already outfit, but the cost is a tough sell past the wife, but for a few thousand $$, seems like the Lagun is a good starting platform and gets me on my way; just cautious as the variable speed might be a better platform to start with? or Lagun is so limited on parts, it would be $$$ to upgrade to old stuff? This assumes good condition; yes, wear dictates a lot. Thanks in advance.

 

[JimDawson]

I guess I would drag this one home if it's mechanically OK. I have one just like it. All the hard work is done, just needs a new controller, and as a bonus it can be operated as a manual machine, best of both worlds.

Bridgeport Clone CNC Vertical Milling Machine - tools - by owner -...

Bridgeport Clone CNC Vertical Milling Machine CNC controller needs work, the owner told me it is a $500.00 part. You can fix it or remove CNC components. Nice large capacity, heavy duty mill. $1,400

sfbay.craigslist.org

You can hang any servos you want on any machine, same with the controller.

 

[D. Kent]

Thanks Jim. I'm a little leery of older stuff and support hardware / software, but I did reach out the seller and mentioned that if he gets no interest, I'd be interested in removing the CNC components since Fremont is relatively close for me. Yes, most likely will need a fair number of mechanical parts to match my mill, but might be able to pickup a pile of NC parts as a start, for relatively cheap.....missing a $500 card.

I do have a dumb question about typical control. Do CNC systems normally rely on the motor encoder for position or does it reference a secondary scale (like a glass scale) for positioning? I'm wondering if, as I first think about DRO, are there slides that would be more desirable for future X-Y NC, if a typical system relies on them for positional accuracy? Maybe that's pie in the sky thinking, but my eventual plan to perform some conversion has me thinking I should check this box as I browse....are DRO scales used by system and if so, is there something I should be looking for in the slides? Positional accuracy tolerance?

Thanks again.

 

[JimDawson]

Thanks Jim. I'm a little leery of older stuff and support hardware / software, but I did reach out the seller and mentioned that if he gets no interest, I'd be interested in removing the CNC components since Fremont is relatively close for me. Yes, most likely will need a fair number of mechanical parts to match my mill, but might be able to pickup a pile of NC parts as a start, for relatively cheap.....missing a $500 card.

Not exactly sure what you said above. What I meant about all of the hard work being done is that the ball screws and motors are mounted and is ready for a new controller to be stuffed into the existing electrical enclosures. The existing controller parts are pretty much useless, but you can most likely reuse some of the power handling components.

That machine is a 4VK frame with box ways, heavier than the FT1. Most likely made by Topwell in Taiwan. Parts are available.

I do have a dumb question about typical control. Do CNC systems normally rely on the motor encoder for position or does it reference a secondary scale (like a glass scale) for positioning? I'm wondering if, as I first think about DRO, are there slides that would be more desirable for future X-Y NC, if a typical system relies on them for positional accuracy? Maybe that's pie in the sky thinking, but my eventual plan to perform some conversion has me thinking I should check this box as I browse....are DRO scales used by system and if so, is there something I should be looking for in the slides? Positional accuracy tolerance?

Thanks again.

The answer is: It depends. It could be either or both. You really are most interested in where the table is at, rather than the motor. This takes a lot of the error out of the system. My preference is to use 1 micron resolution magnetic scales, and close the loop at the controller level.

 

[pontiac428]

You're in California, which has more Lagun mills per capita than any other state. Lagun made a series of CNC servo versions of their popular FTV series manual mills. As a Lagun owner, I pay attention, and I see those servo mills go for the same price as the manuals, but they seem to sell slowly because updating CNC machines is a niche hobby. You could get one of those, pop a new controller in it, and get up and running ahead of the game. Probably cost less and work better in the long run, too. Is that learning curve looking like a cliff to you yet?

 

[mksj]

I used a friends Lagun FT2 CNC, but he mostly used it in manual mode. Could do some simple programming steps if one wanted. They ke factor is what Jim Dawson mentioned is that upgrading an existing non-cnc version is probably not practical and will not be cost effective. The CNC models come with ball screws, oilers, drives, etc. so you would be replace the control system/wiring, and but not having to retrofit the mechanical s is a significant cost savings. Parts for the Lagun can be quite expensive, I had looked at a few years ago and most needed work on the variable speed head, drives did not work and they no longer met shop tolerances. Most of the shops were converting to dedicated CNC mills. A stepped pulley belt drive would be preferable to a Reeves drives, and easier to interface a VFD and have it control the speeds. When I looked into parts for rebuilding the Reeves drive years ago it was on the $700-800 for the parts, when I started adding up all the replacement parts I decided it was not worth paying 4K, which is what they were asking at the time when I lived in Tucson, AZ.

 

[Firebrick43]

Thanks Jim. I'm a little leery of older stuff and support hardware / software, but I did reach out the seller and mentioned that if he gets no interest, I'd be interested in removing the CNC components since Fremont is relatively close for me. Yes, most likely will need a fair number of mechanical parts to match my mill, but might be able to pickup a pile of NC parts as a start, for relatively cheap.....missing a $500 card.

I do have a dumb question about typical control. Do CNC systems normally rely on the motor encoder for position or does it reference a secondary scale (like a glass scale) for positioning? I'm wondering if, as I first think about DRO, are there slides that would be more desirable for future X-Y NC, if a typical system relies on them for positional accuracy? Maybe that's pie in the sky thinking, but my eventual plan to perform some conversion has me thinking I should check this box as I browse....are DRO scales used by system and if so, is there something I should be looking for in the slides? Positional accuracy tolerance?

Thanks again.

Accuracy and repeatability is a result of the sum of the components. 1 micron scales are meaningless if the ball screw, couplers, and any reduction method (such as a gearbox) has less accuracy.

Some manufactures such as Mazak don’t used scales and are very accurate. On larger machines they have hollow ball screws that they climate control with an oil chiller. Smaller machine don’t have the thermal growth.

Many do use scales, mostly just as a check. If the scales position does not match the motor encoders within the range defined in the parameter table, a following error alarm will be presented to the HMI panel.

Here is the issue however. If you are asking these questions about a manual Bridgeport style machine you need to do more research.

While not a bad choice for a “hobbyists” CNC, it is a poor choice for high precision CNC.

Most good CNC vertical mills are bed mills not knee mills. Knee mills can work ok as manual machine when you can lock an axis such as the knee, you really can’t in a 3axis CNC mode. Bed mills have much better rigidity especially in z axis moves as there is no quill nor knee.

If you want excellent accuracy I would suggest starting with a commercial CNC bed mill that is physically in good shape but in need of a retrofit of the Control.

 

[Karl_T]

I see you are on the west coast. Look for a shizouka with a dead control. This is NOT a good deal but it is an example

SHIZUOKA AN-S 3-Axis Turret Vertical Milling Machine 51x11" Table BANDIT Control | eBay

Find many great new & used options and get the best deals for SHIZUOKA AN-S 3-Axis Turret Vertical Milling Machine 51x11" Table BANDIT Control at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I watched for one of these for years, they were always in CA.

 

[7milesup]

I see you are on the west coast. Look for a shizouka with a dead control. This is NOT a good deal but it is an example

SHIZUOKA AN-S 3-Axis Turret Vertical Milling Machine 51x11" Table BANDIT Control | eBay

Find many great new & used options and get the best deals for SHIZUOKA AN-S 3-Axis Turret Vertical Milling Machine 51x11" Table BANDIT Control at the best online prices at eBay! Free shipping for many products!

www.ebay.com

I watched for one of these for years, they were always in CA.

Why do you say that is not a good deal? I think that machine looks like it is in awesome shape, plus it already has industrial ball screws and an ATC on it. Rip the control off of it and install a Centroid Allin1 on it, and you would (maybe) have an awesome machine. Of course, an in-person look at it and determining servo motor compatibility with the Centroid system would be warranted. There would be a possibility of being into that machine with a new CNC system for $7k or so. Not bad at all.

 

[JimDawson]

Accuracy and repeatability is a result of the sum of the components. 1 micron scales are meaningless if the ball screw, couplers, and any reduction method (such as a gearbox) has less accuracy.

I would respectfully disagree. Linear scales take ball screws, couplers, reduction gearing, and other sources of backlash out of the equation.