Lorch Schmidt Lathe Restoration

Discussion in 'Your DIY and Workshop Projects' started by Retired, Jul 29, 2018.

  1. Retired

    Retired

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    Hi,

    If you decide to add a new Projects/Workshop section to the forum Ian my I please be the first to add one of my projects. edit (Ian): I've move this to the projects section now :).

    Please accept that I'm not smart or an expert on anything; just a guy into all sorts of interesting things that grab my attention. I'm an apprentice trained mechanical engineer which gets me off to a good start; a mechanical engineer is totally different to a "fitter" I was taught by top engineers to use my head and hands and if I did anything I shouldn't I was certainly in the wrong place working down a deep coal mine; the engineers played rough but I trusted them with my life and I learned a great deal from each of them for which I'm forever grateful. I was working underground at the age of 15 helping but possibly more hindering the engineers.

    A few years ago I saw an old very rough looking metal turning lathe on eBay that caught my attention especially since it was located just the other side of Huddersfield; the lathe is a very rare Lorch Schmidt precision lathe and unlike most Lorch lathes this was floor standing being a full size lathe. I arranged to inspect the lathe and drove over; the lathe was surrounded by other equally rough looking machinery so the seller and I had to make our way to it; this lathe had been sitting in a scrap yard for over twenty years and it showed although it must have been protected from the weather because I could see very little rust; whilst the seller answered his phone I took the opportunity to really give the lathe a close examination moving the slides and checking the controls worked; it was single phase and an extension lead was run to it proving at least it was in some kind of working order. The lathe on auction on eBay had a starting price and looking at the state of it I offered a price as a buy it now but this to include delivery; I was amazed when my offer was accepted and a few days later Bron watched as my latest load of scrap metal arrived on the back of an open wagon.

    Bron generously bought me a soda blaster as a prezzie and I bought a 3hp compressor to power the blaster; I used hard medium in the blaster which was a slow terrible job working on our driveway in freezing conditions. The lathe was completely stripped to its last screw and with a great deal of TLC I went through each part whilst I rebuilt it.

    https://www.ebay.co.uk/itm/Millar-S...854349?hash=item3d6cf2c44d:g:2QsAAOSwQ59Za7YQ

    I'm unable to obtain any information on this particular lathe even on

    http://www.lathes.co.uk/lorchschmidt/

    I spent many hours trying to find details as to its age but without success; having already inspected the lathe I knew in spite of its poor appearance it was actually in good condition with very few signs at all of any wear and this was borne out during its comprehensive rebuild. This Lorch was a flat belt drive which caused no end of problems; I'm used to fast and loose pulleys with flat belts having worked in the pit and I installed new belts to the lathe but never liked them.

    I went to town on this restoration; I bought a top quality Brook motor and the correct DOL starter; I've no problem at all wiring motors; before retirement I worked at Brook Motos for 24 years. I had seen a fully restored Lorch watchmakers lathe and liked the colour so bought the same colour from Paragon Paints which I sprayed on.

    The pictures below tell the story better than text alone but after successfully restoring this Lorch I didn't then have time to play with it but when I did I was disappointed by the flat belt drive slipping. I solved this by installing a completely new drive converting it to 3 phase 1.1kW (2hp) Poly-V drive through a VFD (Huanyang); I'm not a trained electrical engineer but over the years I've picked up lots of knowledge; adding remote controls to the VFD for forward/reverse and speed control proved very testing indeed because of cross talk between signal and power cables which caused me lots of frustration; I understand this problem due to my years of vintage radio restoration but it really caught me out on the VFD; I solved it be separating the signal and power cables and using shielded Cat6 cable for the control circuits. I've never seen it done previously but I wondered if I could run both my fully restored Union Graduate and Lorch lathe from this single VFD; the short answer is yes and I've successfully done it with a switching circuit; both lathe motors are identical so it was just a case of setting up the VFD and installing switching between the lathes; I love to do things differently and to experiment but i will never encourage anyone to play around with mains electricity; mains electricity doesn't take prisoners and a simple mistake could prove the last mistake ever made.

    I take lots of digital images of my projects so I've got a lot of projects on many subjects I'd like to share if of interest; I'd like to see this forum take off with many like minded members contributing; after 55 years I still have a great deal to learn. Here are a few pictures to show what I get up to.

    Kind regards, Colin.

    Back gears installed.JPG
    Back gears installed.

    Back of belt.JPG

    Back of headstock showing unusual drive belt route.

    Drive shafts 1.JPG
    Drive shafts installed.

    DSCN0012.JPG
    Painting underway.

    DSCN0042.JPG
    Carriage assembly.

    DSCN0071.JPG
    Carriage assembly stripped. Images and notes taken due to no workshop manual.

    DSCN0199.JPG
    Headstock components.looking better than new.

    Lorch installation Jan 2014 (15).JPG
    As bought and having been stored for over 20 years in a scrap yard.

    Pulley fitted to motor.JPG
    Top quality Brook Motor painted with pulley installed but since converted to 3 phase Poly-V drive via VFD.

    Restored Lorch Schmidt..JPG

    Looks much better after a lot of TLC restoration almost completed.
     
    Last edited by a moderator: Aug 3, 2018
    Retired, Jul 29, 2018
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  2. Retired

    Retired

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    Hi,

    A few more pictures showing the Poly-V drive installation. The only physical alteration to this rare lathe was to drill a single mounting hole allowing a set screw and nut for the mounting to the bed of the motor platform.

    The Poly-V drive installation was given a great deal of thought by me because I didn't want to mess around with the lathe's originality; I used a Poly-V drive pulley on the motor but utilized the original flat headstock pulleys only needing to use one of the pulleys due to the lathe being converted to 3 phase variable speed; the bottom countershaft pulleys remain in position but are now redundant.

    Adding this new drive has transformed the lathe which now gives it full variable speed via the VFD; forward & reverse; start/stop and most of all no more clicking of flat belt connectors nor slipping belts; the lathe is a joy to own and use. The pictures below show the neat Poly-V drive installation; the headstock mandrel had to be removed to allow new belt to be installed but an easy enough job for me; having run the lathe a while I then checked mandrel adjustment and on initial start up kept a close eye on the mandrel bearings ensuring they ran free without binding or overheating.

    I worked at Brook Motors for 24 years and was kindly given motors that had been in the research/load test department; having done their job such motors were scrapped; I was also given permission to bring home prototype "W" series motors that otherwise would have been scrapped but only on a promise I would never sell any of the motors kindly given to me; both the Graduate and Lorch have two such motors these being top quality inverter rated motors.

    One major problem I've found on this Lorch lathe is that both the headstock mandrel and tailstock bores are not standard Morse Taper which presents difficulty in obtaining chucks and drives etc in fact it doesn't at the moment have a live center for the tail stock but I plan to modify a MT live center and have ordered a three bearing 1 MT live center which I plan to sleeve in the near future. Lorch accessories and parts bring tears to my wallet commanding very high prices.

    Kind regards, Colin.

    DSC00272.JPG
    New Poly-V drive installed; a great deal of thought went into doing this neatly.

    DSC00273.JPG
    Middle mandrel pulley chosen for convenience; only one of the pulleys needed due to variable speed via VFD.

    DSC00307.JPG

    Mandrel removed to allow drive belt installation; not really a job for a novice; getting it wrong could cause damage. The motor is much more powerful than the original motor it now being 1.1kW (2HP).
     
    Retired, Jul 30, 2018
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  3. Retired

    Retired

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    Hi,


    Lorch lathes of any size command high prices as do spares or attachments for these lathes; my Lorch Schmidt really is a beauty but recently it's been driving me mad; when I bought this Lorch I hadn't realized the tailstock and headstock mandrel bores were not of the usual Morse taper sizes hence correct tooling is not only rare but highly expensive; because of this I had considered selling the Lorch which because it's a full sized floor standing lathe would go for a high price then buy something like an Harrison or Denford lathe where tooling can readily be bought cheaply and in quantity.


    Having spent so many hours completely restoring my Lorch and modifying it to variable speed I was very loath to take the easy option and my background of mechanical engineering means I'm taught to use my head and hands; why not make or modify tooling? Only one dead center came with the Lorch and unfortunately this self destructed a few days ago even though it was well lubricated meaning the work no longer had tailstock support. This was highly frustrating and has come at a time when I really wanted to be elsewhere; timber is due to arrive tomorrow for a project I want to get stuck into but today I was free to get into the workshop so I've been experimenting and done well today because my Lorch now has a brand new three bearing heavy duty live center installed; I'm glad the dead center destroyed itself; I've never liked dead centres at all. I've had plenty of fun and frustration though in modifying this new live center which is on a #1 Morse Taper.


    I have plenty of steel round bar stock so cut three blanks which were to be sleeves; the bore would be #1 Morse Taper the outer diameter the same as the original Lorch dead center. A blank was chucked in the Lorch and bored through on axis to just under the minimum diameter of the Morse Taper removing most of the waste to give the #1 Morse taper reamer an easy time. Up to now it had been a straight cutting off and boring but the only #1 Morse Taper reamer I have is also a machine reamer it having a #1 Morse Taper drive end so I was in trouble; this reamer couldn't be mounted in the Lorch tailstock either directly due to the wrong tailstock bore or in a Jacobs chuck mounted in the tailstock? I knew it wasn't going to be easy reaming the #1 Morse Taper into the sleeve blank but I have options; I could have used my floor standing drill press but then I thought I'd have a go at reaming using the Graduate woodturning lathe after all the Graduate has Morse Taper bores; the Graduate already had an engineering chuck installed to its headstock so the bored blank was transferred to this chuck; the reamer was easily mounted into the Graduate tailstock and reaming the blank went like a dream. The Graduate was protected from metal swarf; it was run at a low speed during reaming and the reamer was withdrawn a number of times to clear swarf and to oil it.


    Now the blank had its bore reamed at the correct #1 Morse Taper but the taper now needed machining to suit the Lorch tailstock bore; I had already thought this out and intended to chuck a drill bit into the Lorch headstock chuck with the #1 Morse taper sticking out this to be used as a mandrel but trying to get this to run true proved impossible so a bit of head scratching; why not simply knock the new sleeve straight onto the new live center then secure the live center into the Lorch headstock chuck giving a much more stable mandrel affording better grip in the chuck and better drive. Firstly though the cut angle for the outer taper needed setting up very accurately; I spent ages adjusting the top slide to get the taper angle just right; using a DTI (dial test indicator) against the Lorch original dead center that I had chucked I finally got the correct angle where the lathe tool bit left a very small scratch along the taper indicating this was as good as I was going to get it without expensive attachments. I couldn't use the Lorch tailstock to speed up alignment because the only center I had was damaged hence the amount of time using the DTI but I got there in the end. I locked the lathe carriage to the lathe bed and proceeded to take very light cuts of ten thou at a time; what a delight it was to see the taper slowly appear; whilst reaming and adding the external taper I took great care not to remove too much metal so the digital vernier callipers were used a lot otherwise it would be a case of starting over.


    At last the new special and no doubt only one of its kind in existence was finished and it was now a case of removing the unwanted protruding end of the live center Morse Taper; what a job this was because the taper was hardened and very tough indeed my 4" angle grinder with a steel cutting disc eventually removed the end but with frequent quenching in water of the taper. WOW it worked extremely well; the live center with its #1 Morse Taper now fits the Lorch with the new sleeve. The tailstock centers self eject when the tailstock barrel is fully withdrawn otherwise the longer end wouldn't have been a problem. Hopefully this will help Lorch Lathe owners in a similar predicament I found myself in; I cut three blanks but really I only need the one sleeve at the moment. This new sleeve is made of BMS (bright mild steel) it's not hardened but now I've successfully made it there's nothing to stop me making other sleeves out of silver steel then they can be hardened; I'll see how this mild steel sleeve stands up to use; perhaps I might not need to make another.


    I also own a small Record Power DML 24" woodturning lathe this too having a Morse Taper tailstock bore so what I thought would be difficult in the end I had three choices of reaming; it's nice to come up with a simple solution; I'm delighted to have sorted this out and can now enjoy using the Lorch. I find just because things are no longer available I'll have a go at making what I need from scratch costing very little indeed.


    Just for extra information; Morse Taper sleeves can be bought quite cheaply; another option would be to use one of these sleeves it already having a Morse Taper bore but for a non standard outer taper have the sleeve metal sprayed then ground to the correct taper? I once had a lathe headstock mandrel metal sprayed and brought back to original specification; a company not far from us does this kind of work and they are most helpful fitting small jobs for home workshop owners into their much bigger jobs.


    http://metallizersltd.co.uk/whatwedo.htm


    Kind regards, Colin.

    lathe_002.JPG
    New blank sleeve blank bored just under finished size.

    lathe_004.JPG
    Transferred to the Graduate and reamed using the #1 Morse Taper reamer; worked a treat.

    lathe_005.JPG
    New live center being tested for insertion depth taking a lot of time to get this just right.

    lathe_006.JPG
    New sleeve now fits the live center but still needs its outer taper adding.

    lathe_007.JPG
    Slow painstaking setting up using the DTI; one thou runout I accepted as near enough. As the chuck is slowly turned by hand any eccentricity is easily measured. A DTI is a must to any lathe owner.

    lathe_008.JPG lathe_009.JPG
    Ensuring the Morse Taper of the new live center runs true before adding the taper.

    lathe_011.JPG
    Under way adding the taper using ten thou cuts due to lack of tailstock support.

    lathe_013.JPG

    A lot of time spent but the result I was after; the new live center now is a very nice fit into the Lorch tailstock without the slightest play. I like the extended nose of this live centre giving better tool access.
     

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    Retired, Aug 5, 2018
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