280 VS gearbox sync issue .Dial incorrect?

[Stucapri170]

Hi I am the new owner of a 280 VS .. I bought the lathe locally with the understanding that there was a issue with the motor or VFD fitted .. When the chap plugged it in to show me it just blew the trip out. I tried best I could to look over it and try the gearbox etc .
When I got the lathe home I plugged it in to my workshop supply and hey presto it worked ..But showed an error code on VFD, a Drivesdirect unit . Teco I believe.
Testing the gearbox with the lathe somewhat operating provided more issues . The dial and lever were not in sync with the numbers not corresponding to each other .. ie .. 5 on lever 5 on box dial . As I am led to believe it should ,has others have mentioned on other posts I have read .
I decided before buying to have a good poke around and clean up lube before use , Inevitable that the gearbox would be stripped and checked .Front off lever off and were away
This is a brainstormer had me stumped because the box layout inside didnt correspond with what I thought the gear train would look like .
Looking at the dial numbers I expected the gears to be staggered in diameter not laid up in size order .
To my understanding after selecting neutral on the lever you turn the dial to select the desired number according to the feed pitch chart .
You then engage the lever into the corresponding lever setting .. 1=1 2=2 etc..??? .
Question marks yes as the lever is linked to a drive that raises a gear to engage 1 of 5 in the box as per the dial. Therfore according to the lever position 5 would be the largest diameter gear on the shaft 1 the smallest ..????>>>. Yet the dial is not labelled as such as is the layout of the gearing.
Thje dial would need to be labelled in numeric order surely ..
I found a few isues on stripping down the box other than selection .
1.. there is no taper pin in the feed screwcutting selector shaft on the end gear closest to chuck end . A allen cap bolt was drilled and tapped at 90 to taper holes.
2.. signs of wear on 1 of the gears due to bad meshing .

I would love to know what size the taper pin is that fits this shaft ..
If anyone can shed any light on the dial selector lever sync issue that would be great

[Pete.]

If you take the front plate off the gearbox, for which you almost certainly will have removed the lever on the left with the plunger on it that locates in one of the six holes, it is VERY difficult to work out where to put it back on to get full and proper meshing of the gears. I have done it a couple of times and both times I thought I had got it spot on, only to find that the teeth were only half-engaged and caused damage under heavy feed loadings. I was lucky in that I managed to find a complete gearbox to replace the damaged parts, but I have now completely removed the gearbox off the headstock and re-set the gears by viewing the engagement from the back. If you say that you have damaged gears, this will be the cause. Before you go any further I suggest that you check the straightness of the shafts that hold the gears because one of mine got bent in the process.

[Stucapri170]

Hi thanks for the heads up , I am aware of the necessity of correct meshing , I will try with the borescope first before head stock removal . I am meaning to test measure the sliding action in relation to the dial rotation to check alignment of selector gear . That way I can check the spaced measurement of each gear is correct before fitting and will give some inclination of the meshing across 2 gears .. Dont want no 50/ 50 tooth coverage on half lap .. The selected gear shaft the second input one, in meshing to the 3 ratio selector shaft (left hand leveron top of box) binds a little, looks as if at some point it's had damage on the 5 speed selector shaft end ( chuck side ) and the bearing cap as sheared bearing section off . Either some numpty with a hammer trying to remove it or deflection in shaft at time of accident, snapping it as it is a long bearing .... ( make a new one with a proper bearing/bushing in it at some point).
If shafts are straight and lever dowel locations are correct then the axial meshing of the gears is quite easy to determin . The setting of the meshing from the selector gear shaft could be done by setting the mesh to the smallest gear on that shaft , number 5 on lever . a small hole 2-3mm on the outside of the box and use some kind of location setting dowel . makes future inspection far easier for a long term owner . I could really do with a gear box drawing for my machine but attempted several times on here and failed to open any pdf ???? . And can't upload images ???.

[Pete.]

I Like the bore scope idea, I removed the oil level glass last time and still messed it up. I'll see what I can do for you in terms of images/sketches. I had some sketched out on scrap paper.

There are several things that could be better in the gearbox.

1. If you remove the lever, the quadrant can fall so far down that the pinion falls out of mesh. It's a royal PITA so I drilled a hole in the bottom of the quadrant and put a roll pin in it to make sure the gears always stayed in mesh.
2. Again if you remove the lever when you go to re-fit it you can easily push the pinion through the hole, again falling out of mesh.
3. Because the pinion that lifts the quadrant has a different number of teeth than the number of splines for the lever, it's not good enough just to engage the pinion and fit the lever in the closest spline to do the job. Getting proper engagement involves dropping the lever off the spline, moving the pinion round one tooth, putting it back together and checking if the engagement is closer or further. Of course you can't see the engagement without removing the front plate and you can't select the gears to check engagement with the front plate in place which makes for a lot of fun and swearing.

I'm not advocating headstock removal BTW I'm just saying that since I have the headstock off mine I have taken the opportunity to get proper meshing by viewing through the rear with a torch AND I have marked the gear and quadrant in case there's a next time.

[rpwilson]

If you look in the top section of this part of the site, you'll an item marked something like Viceroy scans ML100. This contains about 5 drawings, the last of which is a metric gearbox drawing (yours is metric, I think the imperial ones are different and have 8 selector positions, not 5). It contains references to individual parts which you should get from the other item which is marked something like ML100 ----ML115 scans. This will involve a fair amount of scrolling through, but most parts are in there somewhere.

Richard

[Stucapri170]

Thanks for the responses all info is helpfull . I spotted the lever spline situation what a ball ache .. how did they factory build the boxes? Surely someone who worked there knows. The feed and thread chart is horrible were it is low down on gearbox cover plate, I may well relocate it and make a inspection hole on the front , big enough to see through . The pinning of the gear is what I had in mind a stop to keep located on the splined gear seems the way forward .
I bought the lathe cheap so I don't mind spending some extra to improve it .. and it came with some good extras , 3 chucks- 5" pratt 3 jaw , pratt 6" independant 4 jaw and a 160mm looks new 4 jaw self centering , new jones shipman revolving center , travelling steady, back plate and full dog setup boxed unused .
Once I have finished it will make a nice lathe .
I have all the parts for a full ballscrew setup from a previous lathe I started a Mach 3 conversion on. A very late model TUD Boxford ,but sold in parts as was really busy at that time with other projects , (only problem is ,it is I think a 20mm, 5 mm pitch hiwin ballscrew and nut set not the 3 mm) . I was considering removing the internals of the gearbox and fitting a large stepper motor ( which I also have a couple of ) and linking it to the pulse generator fitted already on the VS or a variation with a little control to give the variations in lead/feed screw ratios to allow threading and feeds . Arduino based control would be possible with a gui interface on Android tablet or button controlled and lcd display . I would only need a selector gear between the 2 shafts which would be easy to do using whats already there as a parts base . There may be scope as well to be able to use the stepper arrangement as an auto threading stop.
In the mean time I will be sourcing 2 new gears and a replacement shaft . HPC is close to me so will be giving them a visit and working out what to do with the bent shaft , not sure if to make full new or just try machining out the slight runout along with a new bearing cap . 20thou deflection on end .. bent end... bearing mount chuck side 5 speed selector shaft .

[rpwilson]

Thanks for the responses all info is helpfull . I spotted the lever spline situation what a ball ache .. how did they factory build the boxes? Surely someone who worked there knows. The feed and thread chart is horrible were it is low down on gearbox cover plate, I may well relocate it and make a inspection hole on the front , big enough to see through . The pinning of the gear is what I had in mind a stop to keep located on the splined gear seems the way forward .
I bought the lathe cheap so I don't mind spending some extra to improve it .. and it came with some good extras , 3 chucks- 5" pratt 3 jaw , pratt 6" independant 4 jaw and a 160mm looks new 4 jaw self centering , new jones shipman revolving center , travelling steady, back plate and full dog setup boxed unused .
Once I have finished it will make a nice lathe .
I have all the parts for a full ballscrew setup from a previous lathe I started a Mach 3 conversion on. A very late model TUD Boxford ,but sold in parts as was really busy at that time with other projects , (only problem is ,it is I think a 20mm, 5 mm pitch hiwin ballscrew and nut set not the 3 mm) . I was considering removing the internals of the gearbox and fitting a large stepper motor ( which I also have a couple of ) and linking it to the pulse generator fitted already on the VS or a variation with a little control to give the variations in lead/feed screw ratios to allow threading and feeds . Arduino based control would be possible with a gui interface on Android tablet or button controlled and lcd display . I would only need a selector gear between the 2 shafts which would be easy to do using whats already there as a parts base . There may be scope as well to be able to use the stepper arrangement as an auto threading stop.
In the mean time I will be sourcing 2 new gears and a replacement shaft . HPC is close to me so will be giving them a visit and working out what to do with the bent shaft , not sure if to make full new or just try machining out the slight runout along with a new bearing cap . 20thou deflection on end .. bent end... bearing mount chuck side 5 speed selector shaft .

To answer an earlier question of yours, the gearbox GA I referred to before has details of that pin, and all the other fasteners in the gearbox.
Sorry, not sure what you mean by'full dog set up' in your latest post.
Virtually all the gearbox components are available to view as ML115 series drawings, unfortunately, the one that seems to be missing is the shaft carrying the 5 gears, which is the one thats bent I think. I'm not sure where you would source a new one from, as Denford haven't carried spares for many years. The GA indicates a groove in the shaft just where it enters the right hand bearing, so its almost certain that the bend will be there. Being the rough operator that I am, I'd try holding the bearing end in the chuck, indicate till the bend is upwards, then try tweaking the end of the shaft downwards. Chances are you'll be able to get the shaft pretty straight. Turning a replacement yourself is the next option, you don't need the gearbox operational for that.
According to the ML115 series drawings, all the gears are 14DP 20 degree pressure angle (the modern standard). My HPC catalogue, many years old now, doesn't show them as supplying 14 DP gears, but if you are close, its worth calling in and talking to them. Which gears do you need, as some of those in the gearbox have odd tooth counts that might not be commercially available.

[Pete.]

HPC do indeed supply 14DP 20PA gears

http://www.hpcgears.com/pdf_c33/23.126-23.131.pdf

The shaft holding the stack of 5 is a very basic piece of turning but it does have keyways. I have SOME gears if you let me know which you need. BTW the broken end cap is an indication of a bent shaft from poorly meshed gears jumping teeth. I had to make a replacement for that reason.

[Stucapri170]

To answer your question ..A full dog set is the dog drive with drive catch plate ,center, dog etc .. HPC are stocking the DP14 gears in all sizes bossed and plain

The shaft is bent were you mentioned the slight groove at the shoulder of the right hand bearing .. I was thinking of parting this end off, counter bore the shaft and machine a new bearing end on interference fit and pin location . I dont want to go mad with the box just in case I decide to Mach3 it . I have a lot of CNC parts still around , nearly enough to convert the viceroy . Found a USB 3 axis card the other day in workshop loft space , along with parts for a tool post spindle drive for a grinder milling attachment etc . I am unsure exactly the true direction I will go with this lathe .. Onward and upward .

[Pete.]

You might find it easier just to straighten the shaft. I found it no trouble just putting it in a collet, indicating with a dial gauge and bumping it with a plastic hammer.

[Stucapri170]

Pete Thanks but I have tried the hammer on it, but the bearing end is fairly rough with a flat spot on it's full length .
There are also signs of previous tampering of the bodging sort on the shaft end in the form of file marking UUUMMM .
Got a lathe and uses a file to try and round off ... Numpty written all over it .

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[Stucapri170]

Hi Pete the offer of the gears is great thankyou ... it's the 21 and 24 toothed gears on that shaft I need the 24 is worn till the tip is very narrow and the 21 has signs of bad selection meshing with half wear .. how much would you want for the gears ?? I am thinking of removing the VS pulley arrangement and just fitting a 2hp vfd motor setup. and possibly a 2 step pulley .

[Pete.]

Ok I'm a bit confused. My stacked cluster has a good 24 but no 21 at all, the next smallest is a 20. The 24 has rounded sides to the teeth for some reason, perhaps they did it at the factory to aid engagement.
There is a good 21 in the box but it looks like a 16DP not a 14DP. I think it's from higher up in the box.

[rpwilson]

Hi Pete the offer of the gears is great thankyou ... it's the 21 and 24 toothed gears on that shaft I need the 24 is worn till the tip is very narrow and the 21 has signs of bad selection meshing with half wear .. how much would you want for the gears ?? I am thinking of removing the VS pulley arrangement and just fitting a 2hp vfd motor setup. and possibly a 2 step pulley .

I'm not sure about dispensing with the use of the VS pulley system. It has a range of about 4.5 -1 on speeds, and even with that, the lowest speed in back gear is only around 70rpm, which is a bit high for a lathe of its size, if large diameter work is going to be done. Highest speed obtainable on mine, which has the manual speed change, not the electrical one which yours has is a bit less than 1200 rpm, well short of the 1600 which Denford claimed for it. To be honest, after a lot of fiddling about, including the fitting of a new VS belt, I found that Denfords claimed speeds were, to be polite, misleading, or, not being polite, downright lies. I fitted a new inverter with speed control, in order to overcome this. I still run the lathe using the VS speed control, which I like, and only use the inverter speed control to get very slow of fast speeds, beyond the end of the VS range. I don't think that an inverter without the VS still in place, will give you a very good range of speeds, even with a 2 step pulley, at least not without running the motor at excessively slow or fast speeds at the ends of the speed range, which it might not like for extended running periods.
Does your VS speed change mechanism work OK? Tony Griffith's site has some dire warnings about the inability of the speed change motor to work properly when fed 240 v 3 phase.
This is only my opinion, others may differ in their views.

[rpwilson]

Ok I'm a bit confused. My stacked cluster has a good 24 but no 21 at all, the next smallest is a 20. The 24 has rounded sides to the teeth for some reason, perhaps they did it at the factory to aid engagement.
There is a good 21 in the box but it looks like a 16DP not a 14DP. I think it's from higher up in the box.

According to the drawings, that 5 gear cluster should be 32T, 28T, 25T, 24T and 20T. The 32, 28, 25 and 20 are shown with 15 degree chamfers to the edges of the teeth, but the 24T one is marked 'teeth rounded' for some reason.

These are all 14DP, although there are other gears in the box which are 16DP apparently.

[DavidB]

Stucapri170,

In case you weren't already aware of it there is the Electronic Leadscrew controller project already available, see
http://autoartisans.com/ELS/ and http://medw.co.uk/wiki/ELS+Price+List . It might save you time re-inventing the wheel and allow you to get on with other projects. I have no connection with it and haven't used it, I just know it has been around for a few years.

[Pete.]

Ok I'm a bit confused. My stacked cluster has a good 24 but no 21 at all, the next smallest is a 20. The 24 has rounded sides to the teeth for some reason, perhaps they did it at the factory to aid engagement.
There is a good 21 in the box but it looks like a 16DP not a 14DP. I think it's from higher up in the box.

According to the drawings, that 5 gear cluster should be 32T, 28T, 25T, 24T and 20T. The 32, 28, 25 and 20 are shown with 15 degree chamfers to the edges of the teeth, but the 24T one is marked 'teeth rounded' for some reason.

These are all 14DP, although there are other gears in the box which are 16DP apparently.

That would agree with what I have found.

I have a good 24 which you are welcome to. If the other yo need is a 20 then I'm afraid that mine is trashed. If this is the shaft that you have which is bent, I think mine is straight - I will check it and if it's of use than you're welcome to that too. I also have a spare large plastic headstock gear spare if you need it but I would want money for it.

Pete.

[Stucapri170]

oops sorry yes 20 and 24 t that I require . Will check out the leadscrew controller package .. I can easily get a stepper to run the leadscrew at any speed , the tricky part is getting one to run in sync with the spindle without using a long winded system to control this . I found this yesterday while searching for Arduino CNC Google.

https://youtu.be/BaBK9teKUaA

Thing is it may well turn into a full CNC viceroy ..
Thanks for the help ..

[Stucapri170]

Pete your offer is much appreciated .I would like the spare top gear and the shaft and any gears you have spare .. I would pay you for all the items gladly ..

[Pete.]

I'll let you have any gear that you need but I will keep the rest, I did pay £50 for the spare gearbox after all and I would be foolish to let them go. If your 20T and 24T gears are damaged I wonder how your sliding gear is not? Mine got a bit bashed about. Also, on mine the shaft in the quadrant was slightly bent too so it would be a good idea to check that on yours if you've had an engagement problem.