Advice on Bridgeport converted to CNC for sale

[Charlieman22]

At the price you are getting this for, your gas to go get it. Renting a trailer and a fork lift once you get home would still be a cheap option with this unit.

If I might ask, how did the owner of the mill come to make this offer? Did you advertise for a mill? You indicate that it is a 1.5 hour drive, so I assume it is someone you may not know.

Thanks

So about the story...
I had just watched a well known YouTuber yesterday who was offered a Bridgeport.
Looked like you could serve dinner off it.
The ways were unscathed and chromed.
The paint was perfect.
The aluminum was all aluminumy and pretty.
And it operated as smooth as glass.

And I thought to myself. Self: why does this never happen to you?
And as I closed the video, one of the many alerts popped up - and this one was for some scrap sheet metal.
Only at the bottom of the add, it said: "and I also have a mill you can have if you have a big trailer"
So I immediately hit respond, and asked - exactly what kind of mill is this thing I can have?
And he said: "An old Webb. CNC".
Until today - that is what I knew about it.

So this morning - I brewed myself a coffee and drove 1.5 hours to see a man about a mill...
Pictures above tell the rest of the story.
They restore helicopters - and had decided they needed it out of the way.
It had apparently sat in the corner of the shop for a decade.

So it just kinda fell to me - though as these things go - until its in the garage - you never know.
I'm thinking through what I could do to best suit my needs.
I'm hungry to have a working mill - that's where this whole thing started before I found myself in a parking lot with old helicopters.

Some options I'm pondering:
1. Strip off the CNC. Turn it in to a manual. Hey - I got it for free! Put on a DRO and an X axis feed. Maybe put a potentiometer on the existing quill feed and use that as a power quill with no handle (cause I don't know how I would put on a handle.). Perhaps even tear it down, scrub it, paint it my favorite color of green, polish up the aluminum and steel bits. Have a compact 4000lb garage manual milling machine.
2. Put a battery in it, tell the computer where the parameters are (hey computer - they are over here! everything is ok!) maybe even skip the paint part, and figure out how to use it.
3. Take it modern. New servos motors, controller, some kinda screen, etc. etc.

Any thoughts on above?

 

[JimDawson]

I think any of the above would be viable options. #2 would be the most difficult, but Webb is still in business, so maybe.

I would start by cleaning it up and painting your favorite color.

Adding handwheels should be very easy. You should be able to lash up a manual quill operator. Add a DRO and you're almost making chips. You may need to replace the VFD with one that will run on single phase (I'm assuming you don't have 3 phase in your garage)

The existing servos are brushed DC servos with velocity drives, commanded by an analog +/- 0 to10V signal, an industry standard. Compatible with many modern retrofit systems. I still have the original brushed DC servos on my machine. The servo drives on that machine have a 3 phase dc power supply, so a bit of modification would be needed there, not difficult and really only a few bucks (maybe $10?) The nice thing about brushed DC motors is they are very compatible with manual operation via handwheels.

Looks like a fun project.

 

[Papa Charlie]

I am with Jim, you can make it whole again, or convert it to manual, or just clean it up, spend the least amount to make it somewhat functional. Once you have completed any of these, you have an operational mill. You may decide that you want to take a different path and at that time you could turn around and sell the fully operational mill and use that money, along with what ever else you want to add to that and get something else that at that time will fit your vision for the future.

I see units that are in poor condition going for at least $1500 and up to $2500. So you could come out ahead regardless.

It just boils down to what you want to do. You now have options.

 

[Charlieman22]

All - thank you for the input. Helpful all the way around.

I thought you were instant about having a manual capability?

*Edit. Missed this previously.
True - I have been all over the board - and you guys have been patient.
At the outset - I imagined myself spinning a handle with smooth action until the DRO says I have it perfect.
The usual challenge of reality then arose: you can have it quick, exactly as you like, or at a really good price. Not all three.
So i'm trying to stay fluid and hoping a path will show the way - and with a bit of flexibility - find some magic in the end.
When this showed up - heavy/accurate/powerful/ and free... my mind went into overtime on how I could wrangle the asset into a solution.

I think any of the above would be viable options. #2 would be the most difficult, but Webb is still in business, so maybe.

I would start by cleaning it up and painting your favorite color.

Adding handwheels should be very easy. You should be able to lash up a manual quill operator. Add a DRO and you're almost making chips. You may need to replace the VFD with one that will run on single phase (I'm assuming you don't have 3 phase in your garage)

The existing servos are brushed DC servos with velocity drives, commanded by an analog +/- 0 to10V signal, an industry standard. Compatible with many modern retrofit systems. I still have the original brushed DC servos on my machine. The servo drives on that machine have a 3 phase dc power supply, so a bit of modification would be needed there, not difficult and really only a few bucks (maybe $10?) The nice thing about brushed DC motors is they are very compatible with manual operation via handwheels.

Looks like a fun project.

Jim -
There is some gold in there - and some surprises...
(Shucks! I was just celebrating the fact it had a VFD that was going to make my life simple and save me some bucks!)

Suspect the first call from the guys giving it away would have been to Webb - so perhaps there is no real solution to #2 - which is what made it free.
Webb must get that call fairly often...
"You've lost your parameters? Press 2 to hear us say no!"

Ok couple specifics and a basic plan:
- if I wanted cost effective retrofit system that would allow conversational programing and allowed perhaps a smaller box (that thing is killing me) - are there some off the shelf solutions you guys could point me at to browse? Starting at zero here.
- I've circled and numbered what I perceive to be components of the existing system - could someone help me with what would remain with a retrofit, what would go, and the basic nomenclature of the components so I can speak about this with a bit more knowledge?
- would the VFD Jim suggested previously still apply or am I in a whole new realm with 5HP a motor?

My present thinking:
- Get a VFD to power up the motor & use a power supply if I had to to test the DC motors separately (I have a 15V - 50amp one that might work?). Not sure how else I could tell them to spin?
- Schematic of lower end below - first thought would be to tap the face of the Timing Belt Pulleys 13 to mount an adapter of some kind to a handle. The shaft will be too short to give me access to the key (2) otherwise.
- Schematic of head below - same treatment here with Timing Belt Pulley (14). The cover was missing and I actually shot a picture of this today - (the somewhat rusty timing belt pulley pic below). This would mean my quill would have a horizontal wheel which is weird - but if I put one on with a handle - perhaps it would be suitable/livable.
- If everything spun and moved - tear it down/ clean/ learn the machine a bit - perhaps even paint if I wanna get fancy. This is gonna be a big job.
- Then I could either reassemble with conversion kit - or hold on that - add a DRO - and try and make chips manually - depending on the (perceived) complexity and cost.

All - I am really starting at ground zero here - so if you have a few ideas or opinions - please fire them.
- This thing is so damn dirty - would it be a crime of rust creation to hit it with a power washer before it was loaded up to knock off the thick stuff and leave it at the site I am taking it from?!
- Handles! I wouldn't even know where to start looking - which ones are best for shape - or if some are made with some kind of face mount rather than spline so I could just bolt them on the face of the drive pulleys.
Any and all brainstorming is absolutely welcome.
Feels like I have a path here to entering the world of mills/machining.
Thanks gents.
-CM

 

[JimDawson]

Giving it a bath before dragging it home would not be out of the question, especially if you have some Santa Annas blowing and about 2% humidity that day. I would take about a gallon of WD40 to spray it down after washing.

A very interesting design on the X axis drive. The ballscrew is fixed to the saddle and the ball nut moves with the table. Never seen that before. Should make for a very robust system.

A manual Z axis is a little more challenging on this machine, but I'm always up for a good engineering challenge. The goal would be to switch between a conventional manual lever and CNC, switchable with a mechanical lever. I need to think about this one a bit. That's the way mine works. Mine started out life as a manual only, but I can now switch between CNC and manual with a flip of a lever.

#1 Reversing contactor for spindle motor. Remove, not needed. Has been replaced by the VFD
#2 Servo Drives. Keep, needs some slight modification to run on 120VAC single phase. I'll explain the 120VAC later
#3 Main disconnect & fuses. Keep
#4 Supplementary protection (fuses). Keep
#5 240/120 VAC Control Transformer. Keep
#5A Small contactor. Coolant pump relay?
#6 Servo drive power transformer. Remove, not needed.
#7 Terminal strip. Keep, always useful.
#7A Small transformer at bottom. Not sure what it's for, need further information.
#8 Ice cube relays. May be useful, depends on coil voltage.
#8A DC Power supply section for servo drives (behind the brown panel). See #2 above

You are going to basically rewire the entire panel.

New VFD. I have this one on my 5HP air compressor running on single phase, no problems in about a year or so of use.

https://www.amazon.com/Variable-Frequency-Controller-Converter-HUANYANG/dp/B077KSN4C5/ref=sr_1_11?dchild=1&keywords=10%2Bhp%2Bvfd&qid=1621649328&sr=8-11&th=1

Hand Wheels, these should be easy to attach to the existing timing pulley.
You will only forget to fold the handle one time when in CNC mode.

Amazon.com: uxcell a13110700ux0953 16 mm x 150 mm Inside Ripple Hand Wheel Black w Folding Revolving Handle : Industrial & Scientific

Buy uxcell a13110700ux0953 16 mm x 150 mm Inside Ripple Hand Wheel Black w Folding Revolving Handle: Hand Wheels - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

I would go with magnetic scales for the DRO/encoder feedback to the CNC. I buy direct from Ditron in China. I'll get part numbers later. Then comes the question: Spend $150 on a DRO display or jump straight into the CNC controller which is going to have the DRO display built in. You would still be able to use it manually.

The CNC controller/computer hardware you can hold in one hand. The only large thing is the monitor, a 27'' suits my old tired eyes very well. Refer to my post #50 above for a complete CNC system.

Forget about conversational programming, it's really easier to draw it up and post the G code. Or sometimes I just hand write the G code for really simple stuff.

What a fun project.

 

[extropic]

snip>

True - I have been all over the board - and you guys have been patient. snip>

All - I am really starting at ground zero here - so if you have a few ideas or opinions - please fire them. snip>

First, I'll say that Jim is a perfect guy to guide you through the refurbishment of the WEBB, so you're in good hands.

However, saying "I have been all over the board" is, IMO, a minimalistic description.

Since you're a self described noob to machining and H-M, please reply with some description of your personal knowledge, skills and/or experience that you think will be applicable to hobby machining in general and machine rebuilding specifically.

Questions about "how can I . . ." are much easier to answer when we have some idea what the requester has to work with.

Also, the two projects (Bridgeport vs WEBB) are vastly different in magnitude. The $4500, full asking price, for the Bridgeport deal is going to seem REAL attractive well before you cut any chips with the WEBB.

 

[Charlieman22]

Now that response caused an outloud chuckle.
Twice.

Giving it a bath before dragging it home would not be out of the question, especially if you have some Santa Annas blowing and about 2% humidity that day. I would take about a gallon of WD40 to spray it down after washing.

I will be judicious with the water - and generous with the WD. Check.

A very interesting design on the X axis drive. The ballscrew is fixed to the saddle and the ball nut moves with the table. Never seen that before. Should make for a very robust system.

Franken mill. 5 HP, 4K pounds, small footprint, ugly like no other. Maybe we can find a nice angle to shoot a picture from - but have the sense I could stumble into something that cuts chips and is more forgiving of my ignorance than I deserve. I'm in.

A manual Z axis is a little more challenging on this machine, but I'm always up for a good engineering challenge. The goal would be to switch between a conventional manual lever and CNC, switchable with a mechanical lever. I need to think about this one a bit. That's the way mine works. Mine started out life as a manual only, but I can now switch between CNC and manual with a flip of a lever.

Goal now understood. Will ponder as well as I disassemble. Sometimes simple is best.

You are going to basically rewire the entire panel.

Will finally learn. Electrical will be the part I need the most hand holding on.
Unless its something else... ¯\_(ツ)_/¯

I would go with magnetic scales for the DRO/encoder feedback to the CNC. I buy direct from Ditron in China. I'll get part numbers later. Then comes the question: Spend $150 on a DRO display or jump straight into the CNC controller which is going to have the DRO display built in. You would still be able to use it manually.

Mill is free. If we blow $150 on a DRO that becomes redundant down the road - it would still be a steel. Let's just put one on. I'll use it on my second mill someday Point me in the right direction.

The CNC controller/computer hardware you can hold in one hand. The only large thing is the monitor, a 27'' suits my old tired eyes very well. Refer to my post #50 above for a complete CNC system.

Large screen is highly preferred over Star Trek oscilloscope sized screen. If I am going to take the time to actually clean and paint this beast, the least we can do is outfit it with a nice screen. Tho I gotta say - 27" is pretty impressive from 3 feet!

Forget about conversational programming, it's really easier to draw it up and post the G code. Or sometimes I just hand write the G code for really simple stuff.

Now that surprised me. I can barely operate BB code - but will keep an open mind.

The CNC controller/computer hardware you can hold in one hand. The only large thing is the monitor, a 27'' suits my old tired eyes very well. Refer to my post #50 above for a complete CNC system.

Ok - don't laugh. When the term "Controller" is used - is it everything in the box #1-#8 or is it a physical component. (cringed when I typed that)

Since you're a self described noob to machining and H-M, please reply with some description of your personal knowledge, skills and/or experience that you think will be applicable to hobby machining in general and machine rebuilding specifically.

Questions about "how can I . . ." are much easier to answer when we have some idea what the requester has to work with.

My experience with milling machines specifically - and machining itself - is razor thin.
I'm here to learn.
With a little luck - down the road - I'll be able to contribute in return.
As for machine rebuilding - Its a perfect apprenticeship in my view.
I'll learn a ton - and its a great place to start before I make the first chips fly - with good long term benefit.

 

[JimDawson]

Ok - don't laugh. When the term "Controller" is used - is it everything in the box #1-#8 or is it a physical component. (cringed when I typed that)

You haven't looked in the top box yet, there is a reason that it is that large. The lower electrical cabinet is just the heavy power handling stuff, not the control electronics.

 

[Charlieman22]

Ha!
Forgot about that second box.
Which is hard to believe - because it's larger than the head of the machine itself.
Forest through the trees!

Ok - honkin big box with screen at front = controller and has computer in it.
Becomes much much smaller and is matched with much larger flat screen in upgrade.
Other box is basically power handling stuff.
Will ponder a lower profile solution - but most of the actual stuff in there is needed.

Ok - last of the day -
What if I used "virtual" handles something like these?
Then could just mount on outside of timing belt housing as if they were physically connected.
Viable?
Nice to use?
Bad idea?
Would it fly?

 

[JimDawson]

Ditron DRO + Magnetic scales
1)D100-3V 3axis display
2)DMR200 1um read head, 4 required
3)MS200-3M (3 meters tape)
Factory direct from Ditron. sales@dcoee.com
http://www.dcoee.com/



Yes, those manual pulse generator hand wheels are a reasonably good solution, you just need to make sure you get the 6 terminal ones. Might be the best solution to the manual quill problem. The biggest problem is that they lack any tactile feedback when feeding so you can't really feel what you are doing like you can with a mechanical handwheel. I do have one on my CNC lathe and sometimes do some simple turning with it because I have no manual cranks on that machine.