[drumsticksplint]

Hi all,

I've been looking at changing my manual mill for a Bridgeport Interact. They come up for sale quite often in the UK and are quite cheap to buy. I'm just trying to find out a bit more about them before I sell my old mill and find I've made a mistake. I want the Interact for machining aluminium plate and drilling / tapping holes from steel I'll cut on my cnc plasma. I'm just wondering if I'll still be able to do all the things I do on my manual mill, because most of it tends to be touchy feely engineering. Is there any manual override as such for on the fly cutting? I'm hoping that if I find the right machine I'll convert it to mach3 eventually. Also, I should add that I've never used a cnc milling machine before, so be gentle

Any advice would be helpfull.

Adam.

[Shanghyd]

My series 2 interact 2 has a handwheel and I've used that to manually mill some things. I don't think you will get the same feedback on the handwheel as you would with the manual hand crank but its a trade off I guess.
Then you have the MDI capabilities. Tell the table to move to a destination at a feedrate and off it goes. Quick movements without writing a CNC program. I don't have a manual mill just the CNC mill.

[drumsticksplint]

Hi Shanghyd,

Thanks for your helpful reply. I'm becoming more and more fond of this idea, so looks like my manual mill might be up for sale shame cause I love that damn thing, but don't have the spare cash to have both.

How easy would it be for someone like myself who has no gcode programming knowledge to get an interact to do something like a square bolt hole pattern? Is it something I could learn as I go along, or will I be stuck with a machine I can't get to move without knowing it inside out?

[gus]

An interact can use g code, but need not. Conversational is the way to go

The DC spindle versions seem to have some problems, but the vari speed style are pretty robust

[Shanghyd]

My interact has a TNC151 controller. It has both conversational programming and g code. Neither are hard to learn. The Interact also has cannned cycles for drilling, circle milling, slotting, bolt circles and some other operations.
None of it is hard, so I wouldn't worrry about having a large paperweight.

[drumsticksplint]

Thanks for your replies. Seems like It would be very useful for me to have in my shop because its takes me forever to do any machining on my manual mill which has no dro. Something I've never played with is machine tapping. Its something that I require more and more but haven't ever done it on a milling machine. Would I have to use a compression tapping head with the interact? Also, do they have quick change tooling on all the interacts? As this would be an absolute godsend, takes me all my time changing collects!!!

Thanks,

Adam.

[AdeV]

I bought an Interact series 1 Mk2 (the one with the big DC spindle motor). I run all original electronics. My machine has some issues (e.g. you have to let the electronics warm up, otherwise it won't run the spindle), but once she's going, she's great.

You can "manual" mill using either the joystick control, or the handwheel. Neither will tell you by feel that you're overloading the cutter, of course, so you have to listen & watch carefully. Be sure to know where your E-stop buttons are! Feeds & speeds are all settable, and to some extent overridable using knobs on the controller. Some vari-speed heads require manual speed adjustment.

You can download the programming manuals from the Heidenhain website, they will prove invaluable. HH conversational is actually relatively easy to learn, and supports a decent set of commands. And once you've sussed the computer link out, you can at least write the programs sat in the comfort of a chair....


I do all my tapping on the manual machine using a Tapmatic self-reversing head. There are canned cycles in the TNC controller for doing tapping, but according to the manual you need a tap holder with some vertical float in it to ensure break-free tapping. I don't own such a device, nor have I ever seen one (not that that means anything).

Bottom line: Go for it! Yes, you lose the "feel" of a manual machine; you may well lose some of the range too (my Interact will only machine an 18"x12"x6" space), but for everything else it's so much more capable.

[drumsticksplint]

Thanks for your reply AdeV!

I was looking at the series 1 mk2 also, but I might run into difficulties controlling the dc motor once I change the machine over to mach3, which is what I intend to do in the long run. That is unless I find the control is suitable for what I need it for... There are 3 machines I've seen for sale in the last week, but I need to sell my manual mill first to fund this one, typical

I think from how you describe 'manual' milling on the interact its something I just need to get feel for and slow the feeds right down at first...

Thanks for the advice on the manuals, I'll have a look at those later tonight.

Tapping on a machine if I'm honest is something that scares me...therefore so far I've only done hand tapping. I've just got images of either the machine ripping my tap or workpiece to bits or throwing both across the room. I'm sure if I know how to do them properly then none of those would happen. I've seen the floating tapping heads, which I like the look of, but never actually heard from anyone who's used one.

from everyone's advice, I think I'll be buying one of interact models in the very near future. If I can get my head around the control then it should save me a hell of a lot of time and I will have a load of fun playing around with it!

Thanks,

Adam.

[AdeV]

Thanks for your reply AdeV!

I was looking at the series 1 mk2 also, but I might run into difficulties controlling the dc motor once I change the machine over to mach3, which is what I intend to do in the long run. That is unless I find the control is suitable for what I need it for... There are 3 machines I've seen for sale in the last week, but I need to sell my manual mill first to fund this one, typical

I just bought a spare spindle motor from someone who's converting his S1 Mk2, I'll ask him what he used. If you have access to 3-phase, and you get a good machine with at least a TNC151 controller, IMHO there's no reason not to use it as-is. It supports G-codes, or HH, drip-feeding, etc.

I managed to keep my manual mill, I was up to 2 Interacts at one point, but I managed to persuade myself to sell the "spare" one...

Tapping on a machine if I'm honest is something that scares me...therefore so far I've only done hand tapping. I've just got images of either the machine ripping my tap or workpiece to bits or throwing both across the room. I'm sure if I know how to do them properly then none of those would happen. I've seen the floating tapping heads, which I like the look of, but never actually heard from anyone who's used one.

Scour that well-known auction site for a cheap self-reversing tapping head. I was lucky and got a genuine TapMatic SPD7 for about £60, plus another £50-odd for a 2nd collet (brand new from the manufacturer, I hate to think what they charge for the whole head); I typically tap M6 1.5mm into steel @ around 110rpm with it, it's a total revelation. It's worth buying spiral taps as well, they don't need backing out like normal taps.

[mflux_gamblej]

The interact 1 mk 2 is way ahead of its time. I use it with drip feed, 3d machining, cnc tapping, peck drilling - everything. There is no reason to retro fit it, you'll only make it a pile of crap. Heidenhain made one hell of a controller even in the mid-80's.

I can hold 0.001" without trying very hard.

The trouble with these is the spindle drive - if it breaks i hope you're good with a multimeter and mouser.com.

[drumsticksplint]

Hi Mflux,

You've got me thinking actually.... I'd want my machine to do 3d machining, which is why I was contemplating converting it to something like mach3. But when you mention drip feeding and if i've got the right concept of the meaning from a google search then that might eliminate the need to retrofit? What controller do you have on your machine? Seen a few sell recently with the tnc 145. Am I right in thinking that I could design in CAD and then employ a kind of post processor for the gcode, which I could drip feed to an interact??

I've heard of a few problems with the DC drive systems. Though I did see a guy who changed the old drive out and replaced with a newer parker dc drive. I think he was controlling it with 0-10v signals somehow through mach3.

[mflux_gamblej]

3D milling is just a set of xyz moves strung together and in some cases sets of arcs where possible. I use CAM packages to make a toolpath then drip feed it.

My machine has a 151-B control.

There is a caveot here related to drip feeding - that is, that when running 3D milling, there are a lot of tiny movements strung together and the drip feed over serial (9600 baud) cannot keep up with the machine.

It's best to transfer the program to the machine if the program will fit in the memory. If the program can fit in the memory, then the 151-B is just fine.

If the program is huge (which a lot of 3D paths are) then the machine would feed hold everytime it needs to catch up with the serial transfer. Mach 3 will not have this problem.

DC drives have a lot of angry voltage floating around them and sh*t breaks every once in a while it seems. You have to take the configuration / settings very seriously. Don't go messing with the pots on the DC drive control without knowing what you're doing. I've made several posts outlining my experience with my spindle when it wasn't working.

[drumsticksplint]

I've been offered a bridgeport MDI with heidenhain 131 control for very little cash. I've read somewhere that these machines only had a single servo driver and weren't considered to be full cnc, is this correct? I am able to view the machine tomorrow. Failing that, do any of you guys in the UK know where I can get my hands on an interact 1 mk 2 for cheap?? Thanks

[gridley51]

This control is point to point only.It won`t do a curve.It can only go in a straight line.
Better to buy something with at least a 145 control.
These machines switch the servo drive output around the motors.So only one motor can be active at one time.

[drumsticksplint]

Ok, against all good advice I have decided to go ahead with the series 1 MDI. I know its only point to point and all axies share a single driver, but this machine curently offers much more than my manual mill, which I have now sold. Upon viewing the machine I saw it is in great condition having only been used to drill a circular bolt hole pattern in plastic plates all its life. The operator told me that bridgeport loaded the original program and they've used this since new!! I don't think its ever cut metal. My plan is to use the machine as is for a short period until I figure out the best way to retrofit. After all, isn't this machine mechanically comparable to the series 1 full cnc disregarding the control?? I'm hopefully taking delivery of the MDI this afternoon

I plan to document the machine progress seperately, and will provide a link if anyone else is interested.

Thanks for everybody's help thus far.

[mflux_gamblej]

If you can be diligent enough to document it all we'd all watch and learn. Sounds like quite a project.

I'd retrofit even my 151B so that I can run 3D toolpaths with a ball end better. Right now if I use 0.001" scallop and 0.002" facet tolerance, my machine will still feed hold every once in a while because the serial drip can't keep up (at max 9600 baud). A typical program is easily > 10000 lines. The heidenhain 151B can hold only 1000 lines per program so drip feed is the only option.

If a retrofit could be done for around $3000 or $4000 I'd consider it.

I think you'll be retrofitting sooner rather than later though. It's hard to compete even with the 151 and no tool changer.

I'm in the process of buying a lathe w/12 pos. tool turret. I'd like to get a Haas mini mill or similar next to speed up my milling ops.

It's tough to get going in the machining business. If I didn't have a day job, I'd be f***'d