Results 1 to 6 of 6
  1. #1
    Join Date
    Oct 2017
    Location
    Lismore, NSW
    Posts
    7

    Default Aveling I.C. Model Roller

    G'Day All,
    I started the build of this 1-1/2" scale Aveling model roller (designed by Edgar Westbury, circa 1938) early 2013. I found a set of copied original drawings from the Model Engineer magazine of the time, while looking for similar drawings for the Aussie built McDonald roller. The original drawings were drawn to be used with a set of castings that were available in the UK & apparently still are available.
    I scaled up every sheet that had a drawn component on it & worked out a scale for each drawing from a dimensioned size. Then I drew a set of working drawings to enable all components to be either machined from solid stock or to be fabricated. This took three months to complete & finished up with 65, A4 pages of detail drawings.
    As the camshaft is driven via two small spiral gears & this was the first problem to be sorted out. If I could not produce these gears the project would not proceed. Fortunately, I was able to make contact with a brilliant Canadian Modeller, Mr. Allan Suttie who steered me in the right direction as to how to make the two jigs required to enable the gears to be turned by plunging a formed HSS tool bit to depth, producing one tooth groove at a time.
    This worked better than expected after a bit of trial & error.
    To obtain a suitable tool profile a "hob" like cutter of 0.6 module was made to cut a spur gear to be used to grind the tool bit to a suitable profile.
    DSCF3862.jpg

    The two jigs (one for 60˚ & one for 30˚) shown below are held in a chuck & presents the gear blank in a position that enables a groove to be cut around the gear blank surface at the correct angle. It's a rather strange motion that the blank rotates through but, it worked.
    DSCF3947.jpgDSCF3970.jpgDSCF3952.jpg

    The final gears & a little jig to test run them.
    DSCF3982.jpgDSCF3986.jpg

    Once happy with the timing gears the crankcase/water jacket was started.
    The material used for the crankcase was two pieces of 145 x 105 x 25, 6061 Aluminium. The internal cavities milled using both standard & bull nose end mills. A note here, all machining is manually done.
    DSCF4075.jpg DSCF4077.jpg
    Regards & will continue,
    Don.

  2. #2
    Join Date
    Feb 2009
    Location
    moonbi nsw Aus
    Age
    63
    Posts
    242

    Default

    Don welcome to the Forum. I will be looking at this thread with interest as you proceed. Great text and photos!! Isn't it great how "strangers" are willing to help you through difficulties we run into.
    Just do it!

    Kind regards Rod

  3. #3
    Join Date
    Oct 2017
    Location
    Lismore, NSW
    Posts
    7

    Default

    G'Day All,
    Thanks to all those that send a like for this thread.
    To continue with the crankcase, both sides of the c/case were held together using 14, M3 c/sunk head screws positioned around both the internal & external contact surfaces. The bores for the cylinder sleeve & the bearing housings were then finished. The cylinder bore was done first.The centre positions of all bores were set concentric using a wriggler & dial indicator. The c/case was then milled to final form.

    DSCF4096 (1).jpgDSCF4104.jpgDSCF4121 (1).jpg

    The two crankshaft bearing housing were completed next. One was a straight forward turning & milling job.
    DSCN0409.jpg

    The housing with the cam gear housing was a different matter. Rather that try to make it in one piece, it was made as two parts that when fitted together & hopefully would appear as a casting. With the addition of a little liquid metal & a good sanding hopefully this will be the case. The housing being attached with two, M3 socket head screws.

    DSCF4513.jpgDSCF4517.jpgDSCF4518 (1).jpg

    The crankshaft is made from a piece of 4140 steel & was turned as a whole part between centres.

    DSCF4175.jpg Marking out of the main lengths of the webs & journals.
    DSCF4177.jpg First cut to rough out the crank pin.
    DSCF4180.jpg Crankpin roughed out.
    DSCF4183.jpg Crankpin to finished size.
    DSCF4181.jpg Tools used to turn the crankpin. The tool on the right is a piece of key steel, milled to house a piece of abrasive grinding stick. The abrasive was held in place with a finger type clamp & a liberal amount of 24hr araldite. As this tool only had to improve the surface finish, it held together long enough to achieve the desired results. The old HSS boring bar was used to relieve the webs around the crankpin.
    DSCF4195.jpg To turn the journals & reduce the possibility of the crank flexing, a fitted piece of aluminium was placed between the webs & held in position with a cable tie.
    DSCF4199.jpg The crank was then milled to produce the two counter masses.
    DSCF4206.jpgDSCF4208.jpg The finished crank. The threads are M10 x 1, both screw cut. The journals are both 12.5, the crankpin 11.

    This may be a little point of interest. For some time now I have been using pressure pack etching primer paint as a making medium, for two reasons. Firstly, if it is put on lightly, a good line can be scribed into it & the great advantage is that it is not removed by cutting fluids/oils. Secondly, it is readily available. I found in my area that small quantities of marking medium are on longer available, a five litre bottle was totally over the top! I use both black & grey primer. The colour depends upon the colour of the metal to be machined.
    Regards,
    Don.
    Last edited by Don@2480; 11th Oct 2017 at 01:06 PM. Reason: Remove duplicated image

  4. #4
    Join Date
    Oct 2017
    Location
    Lismore, NSW
    Posts
    7

    Default

    G'Day All,
    I tried to post yesterday, but some thing went pear shaped & it did not come up. Try again.

    The cylinder head started as a block of 6061 Al. Turned the threaded spigot first, then completed the milling & drilling.

    DSCF4242.jpgDSCF4248.jpgDSCF4268.jpgDSCF4269.jpgDSCF4265.jpg

    The head is water cooled & has a combustion chamber (forth image) with a valve on either side of the chamber. The hole in the top of the face of the head (third image) is the inlet port. The exhaust port is in the bottom surface of the head. When assembled the piston comes to within 0.5mm of the head. The nut & flange are to seal the water gallery on the head's external surface.

    The valve cartridges have been modified slightly from the original design & I think a good improvement to positioning a very small valve seat in the head. I have had problems with trying to get small seats into heads & stay square to the axis of the valves on previous engines.
    The cartridges contain the valve, seat, body & spring & are sealed with an oil jointing gasket under the flange. The the valve seats are cast iron. The valve stems & heads are silver steel. Heads being silver soldered to the stems.

    DSCF4266.jpgDSCF4267.jpgDSCF4273.jpg


    The cylinder liner was simply a turning & drilling job.
    DSCF4157.jpgDSCF4156.jpgDSCF3833.jpg

    The honing tool consists of parallel arbor & a No2. Morse taper to expand the hone. The taper has a 1.5mm piece of mild steel sheet in it the stop the hone rotating. What should have being made into the arbor is a threaded section at the large end to remove the hone. The brass hone was used for the initial hone & the aluminium hone for finishing. The finishing abrasive was 1200 grit paste & kero.

    The original drawing called for a standard sized spark plug, which is way out of scale. The plug used is a miniature plug with a 1/4" x 32 TPI thread & suits the application far better. Not much of it when compared to a standard plug.
    DSCF4294.jpg

    Regards,
    Don.

  5. #5
    Join Date
    Oct 2017
    Location
    Lismore, NSW
    Posts
    7

    Default

    G'Day All,
    The carburettor body was next to be fabricated. Again I wanted the body to look as though it was cast, so the various components were machined, assembled & silver soldered together. The silver solder used was 45% silver, expensive, but so good to use. The carby body has a spring loaded choke type valve that sits over the main section of the body & is activated by the engine vacuum (2nd image) to open a series of ports in both the sleeve & body. The finished carby shown in the third image.

    DSCF4503.jpgDSCN0405.jpgDSCN0402.jpg

    The exhaust & inlet cams were milled with the aid of a boring head & dividing head. The boring head being set so the tool & cam blank only made contact on one side of the blank. The dividing head was rotated in 5 degree increments, with the tool being fed down the blank width to cut the side of the blank. This process continued until a radiused surface was left unmachined that a radius could be filed to suit the dwell of the cam at fully open position. The sides of the cams did finish up with a larger than required radial lift face, requiring filing to form a flat lift so that the valve opened & closed as required. The cams are both made from 4140 steel & will be heat treated. The cam shaft is a length of 6 silver steel, with the cams attached to the shaft with two M3 grub screws that align with small dimples drilled into the shaft. This sounds a bit dodgy for a cam shaft but, has worked OK.

    DSCF4523.jpgDSCF4528.jpgDSCF4532.jpgDSCF4534.jpg

    The big end bearing is made form phosphor bronze. The bore was turned a little under size & then was scraped to fit the crankpin. The two small tubes are the oil pickup tubes for the bearing lubrication.

    DSCF4552.jpgDSCF4573.jpg

    The piston rings are made from 4E cast iron. The Method that I used to make the rings was found in a Model Engine Builder magazine, where the rings are turned oversize for both the OD & ID. The rings are fitted to an arbor & then slit with a 0.6 mm slitting saw. The rings are put onto another arbour that is turned to the diameter of the piston ring groove & compressed so that the gap from the slitting saw is completely closed & the rings are then turned to the diameter required. The working ring gap is filled to size after the final turning.

    DSCF4172 (1).jpgDSCF4165.jpg19.03.2014.jpg

    All the parts of the engine prior to assembly.

    DSCF4610.jpg

    Regards,
    Don

Similar Threads

  1. H&F Ring Roller
    By Dingo Dog in forum METALWORK GENERAL
    Replies: 7
    Last Post: 13th Apr 2017, 09:26 PM
  2. Replies: 7
    Last Post: 17th Jan 2016, 06:11 PM
  3. Anyone have a section roller near the ACT?
    By Ueee in forum METALWORK GENERAL
    Replies: 16
    Last Post: 9th Jul 2014, 08:31 PM
  4. SOLD: New Bead Roller
    By Greg Q in forum METALWORK - Machinery, Equipment, MARKET
    Replies: 2
    Last Post: 15th Feb 2012, 04:50 PM
  5. hercus model A 1951 model
    By pjh4159 in forum THE HERCUS AREA
    Replies: 5
    Last Post: 21st Aug 2011, 03:15 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •