Help wanted - Colchester Student MK 1.5 Headstock issue plus makers plate artwork

Hi,
I have recently refurbished my Colchester Student MK 1.5 lathe for the second time. With a bigger budget, I did the job a bit better this time with two pack paints and sandblasting where it counted on the cabinet, tray and splashback. During all the chaos, I seem to have misplaced two fasteners which fit into the ends of the countershafts in the rear of the headstock.

This photo shows where the fasteners should go.
My problem is that I have no idea what these screws should look like. My spare parts catalogue is not very clear but I suspect they are probably socket head screws but I am also not sure what thread type they should be. I tried screwing a 1/4" BSW thread in there and I am afraid that it has damaged the internal thread. What I am hoping is that some kind soul could tell me or show me what the screw should look like. i.e. head type, thread diameter, thread length, thread pitch and profile. If anyone can help I would be most appreciative.
By way of sharing I would be happy to supply high quality bitmap or vector images of the round brass makers plate that fits to the end of the bed and the gear selector plate which is fitted to the front of the headstock. Both of these were damaged on my machine so I recreated the artwork as digital images and then etched new plates which were then powder coated in black and clear.

Here is a pic of my finished lathe.

Purists will tell me that the colour is not original but I like it and all the other machines in my shop are that colour so it works for me.

Looking forward to some guidance on this.
Regards,
Preso

Hi Matey, we've got the later version of that machine but I suspect the screws are the same. I'll see if I can find out what they are tomorrow.

Regards, Tyrone.

Hi Preso, I have the plain bed Mk1 Student, but have the manual which covers the Mk 1.5 (in pdf, can send you a copy if you like! [email protected])

screws as follows

Illustration number part No size.
5770 47-223 5/16" unc hex head cap screw x 1/2" long
5771 47-226 5/16" unc hex head cap screw x 7/8" long

Phil
UK

Those plates look great. I've been going to do the aluminum ones on my Clausing for several years. I did the artwork a long time ago. It seems like there's always something else that's more important than that.
JR

Thanks Phil, looks like you've saved me a job tomorrow. Regards Tyrone.

Thanks guys,
So much information so quickly. Great! I was given a MK1.5 manual and instruction/spare parts catalogues for the 6" Student and 12" Dominion lathes years ago but they are photocopies of the originals and the images are just a bit fuzzy so it was hard to tell what fasteners I needed. I am guessing those screws are to retain the bushes in the headstock and don't really do anything to take up lateral movement of the shafts. In any case the lathe seems to be working fine without them. During the strip down I bagged and labelled all the parts and kept everything in two large boxes. I wound up with one 5/16 UNC hex screw left over but who knows what happened to the other one? This time around I have fitted a Sino two axis DRO and replaced the original 12V incandescent work light with a LED light on a flexible gooseneck attached to an extension of the cross slide. The extension is a home built aluminium casting which was needed to mount the rear end of the KA500 slim glass scale. The other scale is a KA300 fitted on the large flat area at the rear of the bed. I will post some photos of the set up later if anyone is interested.
With regard to the brass plates. I have since retired from teaching but one of my teaching areas was Graphics. I had lots of experience with vector drawing programmes so with some effort I was able to turn some low resolution bitmap images I found on Google into high quality vector images. Vector images are preferable for CAM programmes to work with and since I own a 40W laser engraver I was able to use it to process the brass plates. The workflow I used was like this:
1 Cut the plates oversize by a few millimetres.
2 Prep the brass by sanding lightly with a Scotchbrite pad.
3 Paint the plates with etch primer and ordinary black acrylic car paint. I used a spray can. The acrylic was just to protect the etch primer which can be dissolved fairly easily with alcohol.
4 Use the laser engraver to burn off all the paint in the areas where you want the brass etched away. I had to invert the original images and although the vector art can be inverted, it can be tricky since you often need to reorder the layers of the image. So, I converted the vector to a high quality bitmap and inverted that instead. If you don't have access to a laser engraver it is possible to use some proprietary iron on resist of the type used by printed circuit board makers.
5 I then etched one of the plate with ammonium persulphate (as used for etching PCB's) but it took a long time and I had to warm up the solution. The other plate was etched electrolytically using a power supply, sulphuric acid as an electrolyte and a copper cathode. This seemed to be quicker and easier to control. At the end of the day you need to have the etch around 0.3mm deep.
6 I have a home powder coat gun so I cleaned off the remaining paint with thinners and powder coated the whole plate black.
7 I then laid the plate flat and with a hard sanding block, sanded off all the powder coat on the high spots. I used 600 grit wet and dry to finish leaving a grain running left to right.
8 The plate was then drilled, and the edges trimmed.
9 Finally the plate was powder coated in clear to stop the brass from oxidising.
I have added the two bitmap images as attachments. If anyone wants the vector images I can send them as a PM.
Regards,
Preso

DRO and Worklight Upgrades to Colchester Student MK1.5

Well, I found the missing cap screws for the headstock. Yay! Since then I have completed the fitting of a Sino 2 axis DRO and a 17 volt LED worklight. With regard to the DRO, I purchased a single axis DRO and a long glass scale from a vendor on AliExpress. The plan was to have a compact DRO which would allow me to make accurate movements along the Z axis however, when the parcel arrived, the vendor had sent a large 2 axis milling DRO instead. When I complained that I was sent something I didn't order, the vendor made it plain that I shouldn't be complaining since I had gotten something extra for nothing. Rather than going through the hassle of sending the unit back I ordered a short glass scale for the lathe cross slide as well. You may well ask why I didn't do this from the get go but the reason was that I couldn't see an easy way of fitting a glass scale to the cross slide due to the unusual way the Colchester Student cross slide is fitted to the saddle. Access is also limited but after a lot of research I found that a KA500 "slim" scale will just fit under the compound slide and so long as an extension is fabricated for the cross slide, it is possible to have an anchor point for the read head of the scale.

My solution was to cast an aluminium extension for the cross slide and screw it to the end of the cross slide using two 1/4" BSW tapped holes already provided. This extension is also a perfect place to add a spigot for a worklight. (More on that later). I guess the cross slide extension could be welded from steel or just a simple bracket would do the job, however I like casting things and I have a 3D printer which allows me to print the patterns for the castings.
I cleaned up the castings on my manual mill and cut a pocket to clear the ways of the saddle with my CNC mill. The finished, machined casting was then powder coated in black and fitted to the cross slide with socket head screws. I had to drill and tap one hole in the side of the cross slide and one hole in the cast extension to anchor the scale. A simple aluminium bracket was screwed to the back of the apron to anchor the read head. All the holes in the bracket had slotted holes to allow for alignment. I shortened the very long flexible metal conduit that came with one of the scales and used the offcut on the worklight.
The DRO itself is fitted to a cast bracket on the back of the headstock.

It is the same bracket that was used to mount the original worklight that came with my lathe. I scrapped the long extension arm that came with the DRO and turned up a simple spindle which fits into the bracket. The DRO is mounted on top of it.
The worklight was actually a cheap 17V LED reading lamp which came with a spring loaded clip for clamping to a desk or bed head. I scrapped this but kept the nut and spring washer so that I could bolt the chrome plated spigot directly to the cross slide extension. The light came with an in line switch and a small transformer/plug. The power to the light was via a light-ish figure 8 cable which I figured would not last to long amongst the swarf and coolant at the back of the lathe so I scrapped the switch and used the left over flexible metal conduit to sleeve the power cable. I fitted a better quality rocker switch into a 3D printed housing which clamps directly to the spigot for the worklight.

Now it is possible to aim the light directly at the tool and the lit area follows the cutter everywhere it goes!

Remember that I said the vendor sent me a milling DRO? Well, that means that there is no radius/diameter switch for the cross slide. The Colchester Student micrometer dial is calibrated as diameter units and I well used to working this way. It annoyed me that the DRO would only read radius units. However, there is a workaround. I read on another user's post that the SINO DRO has a setup menu that allows the resolution of each scale to be changed. Mine is a 5 micron scale so setting it to a resolution of 10 microns effectively doubles the reading for each unit. Crisis averted!

Regards,

Preso

I'm unfortunately useless in helping your issue, but as the owner of a 15x48 mk 1.5 that looks NOTHING like that, I just want to say good work. She's a beauty!

@Preso I have sent you a PM requesting the vector file for The World Turns artwork. I need to make a new plaque for my Student restoration project.

@Preso, would you please measure the external diameter as well as the CL to Cl of the two top mounting holes of the brass The World Turns plaque for me? We are struggling to determine the correct dimensions of the SVG file.