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  • Dodgy Bridgy

    I have just acquired a Bridgeport. I presume 6-68 on the data plate gives away its age
    It is seriously mucky and the quill feed does not work. Otherwise all seems and sounds OK
    Apparently the quill feed expired with a bit of a bang while in the hands of an inexperienced operator (just like me)

    Couple of questions.

    Is it possible to run it on a 230v VFD and still retain the two speed head motor ?
    Will a single VFD be happy to run also the traverse motor and the coolant
    Where (in the UK) is the best source of spares?

    I have downloaded a copy of the manual
    Is there a better breakdown of the head elsewhere and can anyone provide a link.
    Any other advice ?

    It seems I cannot post attachments so no pics so will try a link to photobucket
    http://s270.beta.photobucket.com/use...rt011.jpg.html

  • #2
    That's my old POS !!!!!!!!!!!!!!!!
    .

    Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



    Comment


    • #3
      Previous owner must have been a clumsy bastard.

      Comment


      • #4
        Originally posted by bandsawguy View Post
        Previous owner must have been a clumsy bastard.
        This explains all the murky waters.

        I wouldn't hookup more than one motor to a VFD, as the VFD may not like it.
        Amount of experience is in direct proportion to the value of broken equipment.

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        • #5
          It sure looks like John's shop. No floor to be seen there.

          Brian
          OPEN EYES, OPEN EARS, OPEN MIND

          THINK HARDER

          BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE

          MY NAME IS BRIAN AND I AM A TOOLOHOLIC

          Comment


          • #6
            John,
            Now we have had a laugh at your expense, answers to questions in hopefully the same order.

            Do not worry too much about the quill power feed, they are notoriously weak, in fact the book says not to use drilling with a drill greater than 3/8" I used one for years with no power feed, drilling boring etc and you soon get a feel for it.

            Only three ways you can retain the 2 speed motor on UK supply.
            [1] Use a transwave converter from 240v to 440 v, probably the cheapest option using the original motor, but not the best as they only produce 2 phases and ghost the third phase.

            [2] Rotary converter from 240 to 440, A lot smoother but you have to have this running all the wile you are using the machine, also expensive over here.

            [3] Use one of the 240v in 440v out VFD from someone like Drives Direct, problem with these are they are expensive and a bodge that drives direct do themselves by messing with a standard inverter and there is no CE or anything on them.

            However if you want to use a VFD there is no need for a two speed motor as the VFD will give you the same speed range.
            This is a Bridgy step speed head with a 3HP motor fitted ready for a single phase VFD, this is probably the cheapest option.


            Traverse motor and coolant pump hardy take any power so if you feed 240v single phase into any two phases and then connect a big capacitor out of a fluorescent light across live and the 3rd phase it will work. it will be down on power but you will still have enough.

            Spares, there is a company near Bridlington, Braitwaites who carry spares. http://www.braithwaiterebuild.co.uk/index.html


            Book ? Download this
            http://www.stevenson-engineers.co.uk...%20Rebuild.pdf
            .

            Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



            Comment


            • #7
              Thank you Sir John!

              I had actually found (and downloaded) that book but not had time to read it yet.
              Will try Braithwaites ( might be a good excuse for a weekend on the coast)
              Suspect I will go for the motor/vfd option. I had wondered if that might be the route but still best to ask!

              I am intrigued by the 240 v plus capacitor route.
              Any idea what size capacitor (3 and 4 micro farad are readily available to me)
              Is this generally an OK route ? would it work on my Bantam for example ?
              Can you explain the principles involved?

              Any other useful hints from anyone?

              Comment


              • #8
                Originally posted by John Stevenson View Post
                However if you want to use a VFD there is no need for a two speed motor as the VFD will give you the same speed range.
                This is a Bridgy step speed head with a 3HP motor fitted ready for a single phase VFD, this is probably the cheapest option.
                That looks familiar, I've got one of those on my BP clone! (Thanks to John).

                My old Simovert Inverters were proving troublesome, so now I'm running mine from a Huanyang.

                I am intrigued by the 240 v plus capacitor route.
                Some people seem to have trouble running suds pumps from a static converter, they may need a starter circuit to get the motor up to speed. The Transwave converters have one.

                I've built a few converters using the information on this site; http://www.waterfront-woods.com/Arti...econverter.htm
                Paul Compton
                www.morini-mania.co.uk
                http://www.youtube.com/user/EVguru

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                • #9
                  Go with the VFD you won't regret it, its aw sum being able to vary the speed while milling or drilling, I start a little slow and work up, was milling some grooves in aluminum 1 1/4" dia. 1/2" deep being able to vary the speed while milling priceless.

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                  • #10
                    I think it was 8 uF per kW of motor power, it's been too much time since I last did 1-phase conversions. And it has to be a motor running cap.
                    Amount of experience is in direct proportion to the value of broken equipment.

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                    • #11
                      Just out of curiosity Sir John:-

                      Where do you buy your motors ? I have had motors from the inverter suppliers in the past but a local electical engineer buys a number from machine mart and seems to think they are OK

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                      • #12
                        Direct from the importers.
                        They are one of my customers in that I modify loads of new motors for them to fit special jobs, older machines where the flange and shaft size are not standard.
                        I also use a fair amount of 3HP motors on a job of mine, just had 2 more in on Monday
                        .

                        Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



                        Comment


                        • #13
                          Originally posted by John Stevenson View Post
                          Thank you for this link Sir John.

                          I had not seen this publication before.

                          I had already purchased "A Guide to Renovating..." prior, but with info from these two different perspectives, it increases my confidence in refurbing my 1967 series 1 J head.

                          Comment


                          • #14
                            As Sir John has said, the quill feeds in Bridgeports (and related clones) are rather weak. When I got my Webb clone, the downfeed had a pause in it when operating. Upon disassembly, it was discovered that one of the bevel gears coming from the worm cradle had lost some of its teeth.

                            I replaced both gears and it works nicely now. Having seen just how puny the parts are in there. I can see why they limited drilling to 3/8". In any case, I don't use the downfeed for drilling to be safe. It works nicely for boring where there is little pressure.

                            A VFD would probably be best for a belt drive Bridgeport with a 1 hp motor. You could leave the belt more or less in one place and use the VFD for speed changes. I prefer Rotary Phase Converters myself since I have a variable head on my mill and I don't change speeds very widely, except to go from high to low ranges.

                            That will be a nice mill when you get it running.
                            Last edited by GNM109; 03-10-2013, 04:31 PM.

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                            • #15
                              I was thinking about one of these
                              http://www.inverterdrive.com/group/M...ECA2-802-4-B5/

                              Driven by
                              http://www.inverterdrive.com/group/A...V-SV008iC5-1F/
                              The latter cos I am already familiar with the setting up having used two on other machines ( before you all shout RPC they are at different sites)

                              However The motor has 19mm shaft
                              2Hp model has a 24 mm shaft

                              Which shaft size is easier to adapt to the Bridgeport pulley which I presume will be an imperial size! (what size?)
                              Are we talking about boring out or bushing down? Is the pulley cast or Aluminium

                              Is Taperlock an option?
                              If so, how would you guys drill and tap the half holes?

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