HS57 Harrison 140 lathe parallel turning test – update

Nice video update! I really like the method of tailstock alignment from Richard King, the scraping expert. Put a chuck on and turn up a small scrap to the exact diameter of the tailstock quill and leave it in the chuck. Bring the tailstock up close to the turned part and lock it (you might need to avoid the gap-bed part). Then with an indicator on the carriage, sweep the indicator over the top of the two diameters, then over the front of the two diameters. This is very sensitive and makes it quick to align the the tailstock as long as you don't take the part out of the chuck. Note that on many lathes, the vertical alignment is very slightly high (0.001-2") on the tailstock side to account for droop when the tailstock is holding a part. Everybody has their own method and I'm sure you will find yours!

Hi, Thanks for taking the time to do the update... I enjoyed the original videos. Take care. Paul,,

Hi, Great video - very interesting. Its easy to go mad doing this stuff as you are trying to understand so many variables at once. I watched this and the first vid also.  I have a Harrison 11 inch which i bought a year ago. I eventually tracked non parallel turning issues down to the headstock not being aligned. I noticed that your lathe has damage on the top slide front where there has been a collision with the chuck at some point in the past. I had similar but worse than yours. It had apparently moved the front of headstock across so that it was turning narrower away from the headstock. You can in fact adjust the headstock alignment and i was able to correct the issue. It may help you to sort out headstock from tailstock non alignment by turning a bar in the chuck only ( unsupported). you need to use a fairly stout bar ( i used 38mm steel), light cuts and honed HSS rather than carbide tips. The comments below on pressure from carbide tips are also bang on in my experience.  Any conicality with this method is not tailstock related , obviously. it may be headstock non alignment or bed twist or bed wear. You'll need to sort that out separately. Send me a message if i can help you further. Ive been down this road. You can assume nothing is as it first seems. good luck.

Another good video Haxby Shed thank you 👍🏻

Always a pleasure to watch your achievements. Never let anyone's criticisms spoil your day. Let them fly to England & show you in person. When a young man had a real machinist tutor me. He walked the walk & talked the talk. Taught me to be very accurate on a very worn old Hendee 16 inch lathe. You'll get there. I learned more by mistakes than by successes. My wife still thinks you're cute.

Hi I have a Harrison L5 on setting up my lathe I found the most critical factor was elimination of bed twist. My garage has a substantial floor slab 12 inches of reinforced concrete. The Harrison manual recommends that the lathe is not bolted down, but the holes used for locating pins. It states that the lathe should be levelled by packing under the four feet. I used a precision level to make sure there was no twist in the bed. It took a few days of putting shims under the feet getting it level leaving it stand over night to settle and then checking it the next day. I also have some bed wear, but find this is not a major issue, the advantage of a v way is that as the v wears (approx the same on each side of the v the saddle and hence the tool tup move vertically down by the amount of wear 2 or 3 though this will have almost zero effect on the diameter. I find a 2 or 3 thou error in the hailstorm centre due to wear in the quill and the barrel bore, and the projection of the quill then it is locked. When turning a shaft that is longer than 6 inches with a tailstock centre for support I set up the tail stock. Lock it then take a cut on the diameter measure at each end, and if it's turning a taper adjust the tail stock side to side with a DTI on the tail stock end of the work on remove the taper, centre towards the tool if dia large on the tail stock end. Another cut and diameter check to ensure so is well it may take a couple of tries. Do not unlock the tail stock or the tail stock quill until the work is finished. If the work is larger diameter in the centre one of two final spring cuts will help bring it to the right diameter along its whole length . Regards Peter Edwards

Good to see further investigation, I think a high resolution bubble level of 0.0005" per 10" is needed before continuing further looking at bed twist (another subscriber has already commented to this effect). The test bar in the tailstock reading is a little concerning for a Harrison lathe, but this could also be a due to potential bed twist. Was this consistent A: along the bed, B: rotating the test bar? Head stock oil at ISO 68 is okay unless using the lathe at zero °C, in my opinion; In my Colchester Master 2500 ( since sold), I changed to ISO 68 hydraulic, and my garage never got colder than 7 or 8°C. Pretty sure the synthetic ATF oil you have, the machine tool manufacturers would loved to have had that choice in the 60/70s'. Thanks for sharing and best regards from the Black Country. John.

Hi Haxby. Plenty of oil lubrication needed on a solid dead centre as the workpiece expands in length without coolant when machining. This may contribute in the deflection of the workpiece away from the cutting tool position hence the larger mid section diameter as well as all other the common factors involved without using a travelling steady. Enjoyed. I'm no expert. A bit of knowledge. Dangerous. Tony

HI like Jimmy McLeod suggested twist in the bed is the same affect as a offset tail stock The chatter is the way u have your tool set up u are pushing the tool in to the work piece there for it tends to dig in adjust your tool so it is more perpendicular to your work piece more of a dragging action will reduce the chatter yes the tool holder is perpendicular to the work but the cutter is not it is pushing in to the work from what I seen in the back ground pic

ISO68 is not equivalent to Tellus 32. The number gives the viscosity in centistokes, in both cases.

Couldn't some of your error be explained by a twist in your bed? After all, you did measure for twist with a carpenters level.

I think you have heard of "testing machine tools by dr. georg schlesinger" otherwise try and google it, you might find it interesting, there is a free pdf download. I have also seen some testing on Youtube. you make really nice videos, thank you