New to me - Colchester Triumph

[Lewis_RX8]

I had found that after all the adjustments I've done over the years, there is one that I never considered (silly me). The saddle front strip 8594/8597. There is lift (a lot) in the front edge, but no adjustable gib strip. The problem isn't insurmountable, but intrguing. Obviously shimming wouldn't work unless it was the removal of.
No signs in parts diagram that there are any? I can mill a new strip, but someone must know the answer. No guesses please The carriage can be clamped to eliminate it during crossfeeding. But not the answer?
View attachment 326204

I was having a look at this aswell , My carriage is very free and what might be a little too free at a guess so was wondering if that needed to be tightened up like a gib strip and as you say there is the square head bolt that clamps down but if thats left on during powerfeeding it would just wear out.

 

[prepman]

Interesting, just for mild or all steels? Im aware that cold will move as the stresses change but no idea if it cuts better or worse.
I dont plan on buying any more mild, used most of it up. There are much better steels at a similar price.

I buy 6-30mm in 6 metre lengths hot rolled, probably made out of old bikeframes and razor blades? It's ok for general use. But I'm not sure the carbon content or heat treating is even throughout. There are easy machine grades which are alloyed with Lead I believe. I made the cross-slide screw out of 3/4" 303 SS which should give good wear resistance against the bronze nut.
>EN 1.4305 grade 303 Stainless Steel provides the best machinability among all the austenitic >Stainless Steels.
Made the chuck backing plate out of EN6 un-hardened.
Had to drill and hand file the keyway as I didn't have the shaper then, nor the internal cutting bar.

 

[prepman]

I was having a look at this aswell , My carriage is very free and what might be a little too free at a guess so was wondering if that needed to be tightened up like a gib strip and as you say there is the square head bolt that clamps down but if thats left on during powerfeeding it would just wear out.

Yes problem is ......to get at it you have to remove the apron. Because of the crown gear, unfortunately you can't slide them apart. (so easy if you could) So to drop the apron you have to partially remove the feed and lead shafts. To disconnect the shafts the feed gearbox needs to be accessed.....etc etc...
I suppose another approach would be to remove the rear gib and move it forward, but not sure if that would help when it came to adjustment, done by shaving the strip down and trying over entire bed.
I've done all this once to replace the feed shaft bushes. How I wish I'd checked then. Oh woe is me! And Thrice Woe!
Quickly back to spindle play......It's free-play that you're looking for not flexing i,e. bending. Which is logically zero with preloaded bearings. Apply enough force then anything will give.

 

[Kram]

Nice job on the back plate!

There are easy machine grades which are alloyed with Lead I believe

Free machining with sulphur is good, En16m. Turns similar to brass, huge DOC's possible, sprays small chips everywhere, but same strength as normal en16, can be hardened. Theres a guy on ebay selling 16mm * 200mm long bar ends at good prices.
Id want to get some in 30-32mm but 6m lengths are going to cost a bit.

 

[prepman]

Nice job on the back plate!

Free machining with sulphur is good, En16m. Turns similar to brass, huge DOC's possible, sprays small chips everywhere, but same strength as normal en16, can be hardened. Theres a guy on ebay selling 16mm * 200mm long bar ends at good prices.
Id want to get some in 30-32mm but 6m lengths are going to cost a bit.

Thanks. I took note from 'This Old Tony' first before I made it. Ironically keyway was a doddle if a bit labourious.
Just had a success parting 2-1/2" (63mm) bar. I won't pretend to say it cut like butter, but it did cut without anything nasty. This is after preloading the bearings, hopefully correctly.

 

[Lewis_RX8]

Had some more sucsessful go at thread cutting today , Well at first it was a few TPI off what I selected on the table which seemed odd but I had in the 42 tooth gear which is designed for cutting special threads in a second table at the bottom I had to change to the standard 36 tooth gear so I could cut the majority of the threads including this which was a 5/8 UNF 18TPI

Zeus book I asked for at Christmas was very handy for thread depths and getting the right sizes without messing about on google for ages can see why they occupy a lot of top pockets in overalls

Picked out right tip and scratch pass was when I noticed the gearing problem , That was then sorted and checked against a 18TPI gauge and confirmed it so started cutting away. It is far easier to cut threads in imperial as the dial can be used so no messing about in reverse thankfully. Not tried the black magic Rapid screw cutting gearbox but I will at some point. Thought best to learn the basic method first without cheating and I am in hurry.

Threads fit well and happy with the part , Was a fitting for air comp line

Also had a go at the tailstock alignment , Would appreciate @fizzy chiming in on how he sorted his which I believe was also 12 thou too low.

The turning centre was speaking weird and would not clamp in properly so i got it in close by turning a taper in the lathe then adjusting to as close as I could by eye

Then tried a test bar but don't think I am quite right here , Tailstock was engaged well enough it was hard to spin the work piece and the turning centre separately they wanted to spin together.

However 2" bar may be too big to try and measure how the tailstock is deflecting it too one side however all I can find in the right length at the moment.

Was showing 0.02mm out which doesn't seem much going off by me aligning it by eye hence me being skepital about the measurements but It will do for now I am sure.

 

[Pete.]

That bar might be a bit stout for doing test cuts in the Chuck and using a centre. If your intent on using it like that don't grip too much of it in the Chuck.

 

[Lewis_RX8]

Cheers I will try gripping a small section of it but will have to get a smaller dia bar to get a proper reading.

 

[Pete.]

A better way would be to put the bar in the Chuck poking out a bit then turn the last couple of inches of it the same diameter as the tailstock ram. Then you can bring the end of the ram up to the end of the bar and run a dial across from one to the other. If they read the same the tailstock is aligned

 

[Lewis_RX8]

Not seen that idea before but a good way to check runout without relying on the bar deflecting. Cheers

 

[Pete.]

Not seen that idea before but a good way to check runout without relying on the bar deflecting. Cheers

Be careful with your terminology mate. It doesn't check runout, it checks alignment.

 

[Lewis_RX8]

Ah I see , for runout it needs to rotate out of line where the tailstock is static

I'll get there , Learning as I go

 

[minimutly]

A better way would be to put the bar in the Chuck poking out a bit then turn the last couple of inches of it the same diameter as the tailstock ram. Then you can bring the end of the ram up to the end of the bar and run a dial across from one to the other. If they read the same the tailstock is aligned

Ooer, that's a thickish bar on a triumph. I was going to suggest turning a step in one end of your bar, turn it around and put the step in the chuck. Put your tailstock with revolving centre in and away you go.
Have you checked the mt at the tailstock and on your centre are good with no dings?

 

[Lewis_RX8]

Ooer, that's a thickish bar on a triumph. I was going to suggest turning a step in one end of your bar, turn it around and put the step in the chuck. Put your tailstock with revolving centre in and away you go.
Have you checked the mt at the tailstock and on your centre are good with no dings?

Had a quick check and seemed all good to me, Will get a torch on the inside taper and double-check. Not sure quite what you mean after away you go , Just take a cut and measure the step?

 

[fizzy]

Had some more sucsessful go at thread cutting today , Well at first it was a few TPI off what I selected on the table which seemed odd but I had in the 42 tooth gear which is designed for cutting special threads in a second table at the bottom I had to change to the standard 36 tooth gear so I could cut the majority of the threads including this which was a 5/8 UNF 18TPI

Zeus book I asked for at Christmas was very handy for thread depths and getting the right sizes without messing about on google for ages can see why they occupy a lot of top pockets in overalls

Picked out right tip and scratch pass was when I noticed the gearing problem , That was then sorted and checked against a 18TPI gauge and confirmed it so started cutting away. It is far easier to cut threads in imperial as the dial can be used so no messing about in reverse thankfully. Not tried the black magic Rapid screw cutting gearbox but I will at some point. Thought best to learn the basic method first without cheating and I am in hurry.

View attachment 326337

Threads fit well and happy with the part , Was a fitting for air comp line

View attachment 326338

Also had a go at the tailstock alignment , Would appreciate @fizzy chiming in on how he sorted his which I believe was also 12 thou too low.

The turning centre was speaking weird and would not clamp in properly so i got it in close by turning a taper in the lathe then adjusting to as close as I could by eye

View attachment 326339

Then tried a test bar but don't think I am quite right here , Tailstock was engaged well enough it was hard to spin the work piece and the turning centre separately they wanted to spin together.

However 2" bar may be too big to try and measure how the tailstock is deflecting it too one side however all I can find in the right length at the moment.

Was showing 0.02mm out which doesn't seem much going off by me aligning it by eye hence me being skepital about the measurements but It will do for now I am sure.

View attachment 326340

Is your tailstock also 12 thou too low? Very odd if it is!

 

[Lewis_RX8]

Is your tailstock also 12 thou too low? Very odd if it is!

No , well I don't think so was meant to read if yours was out of alignment and also too low.

 

[prepman]

Had some more sucsessful go at thread cutting today , Well at first it was a few TPI off what I selected on the table which seemed odd but I had in the 42 tooth gear which is designed for cutting special threads in a second table at the bottom I had to change to the standard 36 tooth gear so I could cut the majority of the threads including this which was a 5/8 UNF 18TPI

Zeus book I asked for at Christmas was very handy for thread depths and getting the right sizes without messing about on google for ages can see why they occupy a lot of top pockets in overalls

Picked out right tip and scratch pass was when I noticed the gearing problem , That was then sorted and checked against a 18TPI gauge and confirmed it so started cutting away. It is far easier to cut threads in imperial as the dial can be used so no messing about in reverse thankfully. Not tried the black magic Rapid screw cutting gearbox but I will at some point. Thought best to learn the basic method first without cheating and I am in hurry.

View attachment 326337

Threads fit well and happy with the part , Was a fitting for air comp line

View attachment 326338

Also had a go at the tailstock alignment , Would appreciate @fizzy chiming in on how he sorted his which I believe was also 12 thou too low.

The turning centre was speaking weird and would not clamp in properly so i got it in close by turning a taper in the lathe then adjusting to as close as I could by eye

View attachment 326339

Then tried a test bar but don't think I am quite right here , Tailstock was engaged well enough it was hard to spin the work piece and the turning centre separately they wanted to spin together.

However 2" bar may be too big to try and measure how the tailstock is deflecting it too one side however all I can find in the right length at the moment.

Was showing 0.02mm out which doesn't seem much going off by me aligning it by eye hence me being skepital about the measurements but It will do for now I am sure.

View attachment 326340

Ah, so you did have the wrong gear in the chain? Might explain your surface finish?
I shimmed my tail stock with brass shim between base and body, after checking it with a centre turned in the chuck (as you have done) and the old flat piece of steel trick between points. The tailstock at end of bed alignment I did with a test bar between centres with drive peg in one end to engage with the chuck jaw. It shows up misalignment but not on which axis. That's for clock gauges. Although after height was corrected most probably across bed? That's what I assumed.

 

[prepman]

Had some more sucsessful go at thread cutting today , Well at first it was a few TPI off what I selected on the table which seemed odd but I had in the 42 tooth gear which is designed for cutting special threads in a second table at the bottom I had to change to the standard 36 tooth gear so I could cut the majority of the threads including this which was a 5/8 UNF 18TPI

Zeus book I asked for at Christmas was very handy for thread depths and getting the right sizes without messing about on google for ages can see why they occupy a lot of top pockets in overalls

Picked out right tip and scratch pass was when I noticed the gearing problem , That was then sorted and checked against a 18TPI gauge and confirmed it so started cutting away. It is far easier to cut threads in imperial as the dial can be used so no messing about in reverse thankfully. Not tried the black magic Rapid screw cutting gearbox but I will at some point. Thought best to learn the basic method first without cheating and I am in hurry.

View attachment 326337

Threads fit well and happy with the part , Was a fitting for air comp line

View attachment 326338

Also had a go at the tailstock alignment , Would appreciate @fizzy chiming in on how he sorted his which I believe was also 12 thou too low.

The turning centre was speaking weird and would not clamp in properly so i got it in close by turning a taper in the lathe then adjusting to as close as I could by eye

View attachment 326339

Then tried a test bar but don't think I am quite right here , Tailstock was engaged well enough it was hard to spin the work piece and the turning centre separately they wanted to spin together.

However 2" bar may be too big to try and measure how the tailstock is deflecting it too one side however all I can find in the right length at the moment.

Was showing 0.02mm out which doesn't seem much going off by me aligning it by eye hence me being skepital about the measurements but It will do for now I am sure.

View attachment 326340

BTW Good news is the headstock bearings are available the bad news is the price....traced them over net

 

[Johnnybravo]

Something worth looking into that I don’t think has been mentioned is the chuck. If it’s been abused,you will never get a good finish. Get a piece of steel with about a 40-50mm diameter and a smooth finish. Wrap a single layer of paper around it,place in the chuck and nip down. Take it out and look at the paper. If the marks are deeper/ darker at the back and light/ non existent at the front, the jaws are bell mouthed. You won’t get a decent finish with an unsupported piece of material in it. It also shows up when you part off or face material

 

[Lewis_RX8]

Something worth looking into that I don’t think has been mentioned is the chuck. If it’s been abused,you will never get a good finish. Get a piece of steel with about a 40-50mm diameter and a smooth finish. Wrap a single layer of paper around it,place in the chuck and nip down. Take it out and look at the paper. If the marks are deeper/ darker at the back and light/ non existent at the front, the jaws are bell mouthed. You won’t get a decent finish with an unsupported piece of material in it. It also shows up when you part off or face material

I have seen jaw marks on steel but will have to check if they are even , Will put some paper on. I have seen people bore or grind out the jaws again but I believe this creates a radius on them which is not ideal.

BTW Good news is the headstock bearings are available the bad news is the price....traced them over netView attachment 326373

Yup heard it was over £1k ,, I guess there is no Chinese copies in the right size so gamet make you pay whatever they want.