Help in identifying antique milling machine.

Advert

Help in identifying antique milling machine.

Home Forums General Questions Help in identifying antique milling machine.

Viewing 5 posts - 26 through 30 (of 30 total)
  • Author
    Posts
  • #572264
    SillyOldDuffer
    Moderator
      @sillyoldduffer
      Posted by Michael Minas on 21/11/2021 07:29:50:

      The more I think about the two holes on the base the more I believe that this casting could have been made or modified for a lathe. In all my research I have yet to see a horizontal mill with only two holes in the base.

      Im not sure where the previous owner had located the motor but I believe it was below the back gear shaft. Is this the best place for it? Or does someone have a better suggestion? I will be fitting a 2.5hp DC 3phase motor with a VFD. Just trying to reduce the array of belts and pulleys.

      I could also try and remove some of the pulleys and replace with gears. I have a few large and small ones tucked away somewhere. Is that a better option? Would like to see some setups.

      I'm certain the casting was purpose made for a horizontal mill, not a lathe.

      On the left is a cast in bed to take the knee, and the base casting comes out to support the spigot holding the screw. The mouldings supporting the top bar are specific to milling as well.

      The design is a simple generic type that seems to have been most popular in the 1920s, but I found pictures of similar layout before WW1 and into the 1940s. After WW2 machine tools take on a more rounded look, and have more guards. From the 1950's tools evolved towards the boxy look and bright paint we know today. Fairly sure it was made between the two world wars. Preferred colour before WW1 was black, grey, and light grey came in later.

      The design is straightforward and could have been made almost anywhere. I suspect, it's 'inspired by' rather than a specific known make, though big name makers often produced cheaper unbranded kit for badge resale. The complete absence of markings suggests rebadging. Could be British (including Australia), German, Spanish, Czech, Italian, North American, Japanese or a number of other countries.

      Early machine tools were driven by a long belt hung from an overhead line-shaft. Later versions from their own electric motor. Machines made in the switchover period (well into the 1940s) often left it to the purchaser to arrange the motor and back-shaft pulleys themselves: I think that's what you have. It would have had 'an array of belts and pulleys' as a cheap straightforward solution.

      If there's space for them to be run safely belts are fine, no need to change to gears. Switching to gears is possible, but would require thinking through the necessary gear ratios. The machine and motor have to be matched. Personally, I like to make use of what's already available rather than make new work such as finding and fitting a suitable gear that fits the pulley shaft, and then engineering the rest of the gear train to the motor. Belts solve a lot of problems!

      Whether the machine is worth restoring depends on it's condition and your stamina! Assess it carefully. As a small production machine, it might be very badly worn. Inspect the bed-ways for grooves, serious dings, and wear hollows. They might require a regrind. Make sure the bearings aren't seized, have high run-out, or are lumpy. Replacing bearings ranges from easy (common standard size) to expensive nightmare (unusual high-end bearings requiring careful adjustment) If the machine came from a school or non-production workshop, it might be near perfect. However, are any major parts missing? It might have been cannibalised. If major parts are missing, finding spares to fit an unknown ancient machine is hard work.

      A complete wreck can be restored if you have the time, money and facilities, but is it worth the effort? Only you can decide. Whilst I'd rather make things than mend old bangers, plenty of others enjoy long restorations! The forum is good at answering questions, and there are a number of threads showing how unpromising kit was brought back to life.

      Dave

      Edited By SillyOldDuffer on 21/11/2021 10:38:36

      Advert
      #572687
      Michael Minas
      Participant
        @michaelminas99836

        Thanks for all the information guys. I have plenty of time on my hands so thats not much of a factor. To be honest the machine hasnt cost much at all and like I said it came with a Victor vertical head. It will be a fun project and theres always times when you need to mill something horizontally. Not sure what but Im sure there is.

        If I run belts between the back gear shaft and the main shaft, how would I be able to tension the belts? In theory I could fit a motor just under the back gear shaft run a belt straight up and then another belt will run across to the main shaft. With a VFD rpm will be controlled somewhat so no need for lots of belts and pulleys. Do I still need to run a belt from the rear of the main shaft to the lower shaft? The one in the photos with the bronze bushing and no shaft running through it.

        A diagram of what you suggest would be great.

        #572702
        Michael Gilligan
        Participant
          @michaelgilligan61133

          On another forum, there are several discussions about ‘updating’ lineshaft macines … including this compact [?] belt installation : **LINK** : https://www.practicalmachinist.com/vb/antique-machinery-and-history/powering-old-lineshaft-b-s-milling-machine-293484/

          Very tidybut still bulky by modern standards

          To me; this clearly demonstrates the advantage of incorporating a gearbox. [a scrapped vehicle being the obvious donor]

          MichaelG.

          .

          Edit: The photo is thumb-nailed in post #9

          This should get you directly to it : 

          https://www.practicalmachinist.com/vb/attachments/f19/120993d1415056524-powering-old-lineshaft-b-s-milling-machine-008.jpg

          Edited By Michael Gilligan on 24/11/2021 08:19:18

          #572708
          Clive Foster
          Participant
            @clivefoster55965

            The picture in Michaels link is very Denbigh-ish. Simple, effective, bulky but you can get at everything. Flat belt spindle drive is a serious constraint with that machine due to the need for significant distance between centres if the system is to drive properly without excessive tension which willrapidly kill the spindle bearings. Objectively that belt is too short really.

            A compact way of getting high reduction with a belt drive system is to use a "back-belt" system mimicking the layout of a lathe back gear. Basic idea is to extend the motor spindle with an accurately running sleeve with the drive gear fixed to the sleeve and a pair of pulleys bolted together free-running on the sleeve via suitable bearings. A second pair of pulleys are fixed to a countershaft a suitable distance away.

            Motor pulley drives one of the countershaft pulleys.

            Second countershaft pulley drives one of the free running pair on the sleeve whith the machine drive taken off the other one of the pair.

            Obviously the pulley pairs going from motor to countershaft and back are two large and two small ones of identical sizes so the belt lengths are the same. Two step downs in series gives a decent reduction ratio without huge size differences. Two 2 to 1 pairs give 4 to 1 reduction taking a 1400 rpm motor output down to 350 rpm which is pretty useful. 3 to 1 pairs gives 9 to 1 and 155 rpm which is probably as slow as you'd ever need to go. 4 to 1 reduction is do-able in a single step with Vee belts but needs plenty of space. 9 to 1 is just too cunbersome and the big pulley will be expensive. Even Poly Vee isnt a great help getting 9 to 1 down to sensible sizes.

            Poly Vee belts let you use quite small diameter pulleys at close centres. For my example 4 to 1 reduction system 2" and 4" diameters would do very nicely at 6" to 8" centres. Easily cut from solid and easy to put a needle roller bearing in.

            Last one I made had the motor and countershaft as a single bulit up unit iwth thw countershaft bracketed above the motor. If I ever do another I shall sit the countershaft on pillars and shim the spacers to set belt tension.

            Or consider raiding the car scrap yards for two pairs of toothed belt camshaft drive pulleys. High quality, 2 to 1 pairs for negligable money 'cos nobody wants them.

            Clive

            #573007
            Michael Minas
            Participant
              @michaelminas99836

              Thanks for your help gentlemen.

              I will keep you informed of my progress. Will probably start on it next year.

            Viewing 5 posts - 26 through 30 (of 30 total)
            • Please log in to reply to this topic. Registering is free and easy using the links on the menu at the top of this page.

            Advert

            Latest Replies

            Home Forums General Questions Topics

            Viewing 25 topics - 1 through 25 (of 25 total)
            Viewing 25 topics - 1 through 25 (of 25 total)

            View full reply list.

            Advert

            Newsletter Sign-up