Member postings for David Haythornthwaite

Thank you Ian for your kind help.

I did manage to upload the drawing to my album and I appreciate your help. Unfortunately due to time pressures with my project to convert my tailstock to lever feed, I have not progressed much further with it and I want to complete the conversion of the tailstock on my machine before perhaps inadvertently misleading others.

Kind regards - I will return to this conversation in due course.

David

I have spent hours trying to upload a drawing of mine to my album - or simply to a forum post and cannot remember how to do it.

Are there instructions on the forum? Yes I know it has to be Jpeg which isn't the best, but I have converted from PDF to JPG and still cannot get it into my album.

Yes I know that I am getting old - but is there a pointer to instructions on how to do this?

Can anyone help?

Kind regards

David H

Thank you Ian for your photographs.

I do not have a proper CAD system but will probably try to do some proper drawings now I have your measurements.

I have been otherwise engaged tonight, but for the moment I have measured the thread on the nut and like you I make the thread to be 1.375" and it is 20tpi. I have only measured quickly with a vernier and my tailstock barrel seems to be 1.111" Diameter. I shall measure more accurately tomorrow with a micrometer as that seems to be a very strange figure either in imperial or metric!

Thanks for your help. Please bear with me as I am a bit slow at present due to a health problem.

William - I shall be interested in any measurements. If the barrel turns out to be 1.25" dia. it would be useful as I could use a length of Silver Steel (Drill Rod to our friends over the Atlantic)

I am hoping to make it so that when retracted it can either stop at the end of natural travel or further out to pop out a taper tool.

Kind regards

David

Hi Ian J

Back in 2016 You corresponded with John Stephenson regarding a long tailstock barrel for your Myford Super 7 and it appears that you bought the long barrel, complete with nut.

I am thinking of converting my Super 7 tailstock to lever feed, making the entire mechanism from scratch. I shall probably start by making a long barrel for my lathe, but I am concerned about drilling / boring such a long hole down it. If convenient, could you please measure your barrel and tell me how long it is so that I can plan how to make this part. I see that the cap has a brass/bronze plate on it and presumably this forms a bush for the tailstock barrel to slide through.I have the normal barrel on my machine and should have no problem in creating a new cap with a bronze bush in it.

I hope that you will be able to advise me.

David H

Hi Woody,

Yes the tumbler gear on the Myford S7 was hardened - and all the gears in the box look as new with perfectly formed teeth and no signs of wear. On the transfer gear, just one tooth had broken off at the root. The tooth jumped over the next tooth and was occupying the valley of the next tooth.

I am very unsure of the reason that it happened, I admit with great shame the the gearbox oil was low and the lower shaft of the gearbox was very tight. It was possible to turn it, but the shaft had to be punched out once the pin had been drilled out of the 16T gear. I hadn't realized that the gearbox was tightening up and when using the powered cross slide to face a 5" diameter lump of EN8, the bang happened and the belt slipped.

The problem with powered feeds is that you get no "feel" with them. I am lucky that it did not do even more damage and I shall watch the gearbox oil level with great interest in future. As a person who once wrote an article for MEW on how to lubricate the Myford, I am ashamed to have let it get low on oil. It would appear that the "captive" screw holding the gearbox to the lathe had been leaking oil.

Kind Regards

David

Speelwerk it was the 39 tooth tumbler gear on the end of the selector arm that broke a tooth - not the large 72 tooth wheel. However I shall investigate your statement that others have put a clutch in the train to protect the box.

Thanks for your input.

David

Thank you Nick, I have sent you a PM.

Hi Brian

The pin that I would need is a 5/32" uk pin and EKP do not supply one. Thank you VERY MUCH for your kind offer to make one for me, but I have just made one from silver steel and it sits nice and snug in the taper hole. I shall only finally drive it home when the main shaft is in place with all the gears on it.

Thanks for your input Woody.

Hi Brian,

Removing the pin from the main shaft was quite an anxious time but drilling out worked ok using the jig that I mentioned to you before. I managed to replace the tumbler gear that had a broken tooth.

The taper pin that would fit the 16T gear would be something like 3.9 mm on the big end and 3.5mm on the small end with a length of 20mm. I bought some 4mm taper pins from RS-online, but of course metric taper pins are specified by the small end diameter and the pins were too big.

The only ones that I have seen are at:

**LINK**

I got quite excited until I saw the minimum order price of $50 !! That is a lot to pay for a requirement of one taper pin!

I suppose if all else fails I could carefully grind one using 4mm silver steel and a tool post grinder but it would be a hit and miss affair as regards the taper angle. No-one seems to sell imperial taper pins in reasonable quantities.

Incidentally, when the crash happened, I was running the gearbox via the Graham Meek metric screwcutting adapter. It was the MYFORD box that was damaged and the Tufnol gears took the strain ok. That speaks well for the new home made adapter.

If you do have a suitable taper pin I would be much obliged.

Kind Regards

David

I have had a "Mishap" with my gearbox on my Myford Super 7. On the main shaft of the gearbox, the smallest gear (part 141 - 16T) is pinned to the shaft with part no 142 Taper pin which is #0x3/4".

I have had to drill out the old taper pin which has not damaged the shoft or the gear. However I cannot find a supplier of the correct taper pin. Myford do nothave any and all suppliers now seem to work on Metric pins.

Does any reader know where I can obtain a no 0 taper pin x 3/4" long.

Hi Brian,

Firstly I hope that you and your wife are keeping well in these difficult times. When I read your post regarding rotating the input housing complete with the the selector, it had me running into the workshop shouting "well done Brian - now why did I not think of that"

On studying the gearbox however, it transpired that this was not possible:-

Looking at the gearbox from the lathe headstock end, it is impossible to rotate the selector CLOCKWISE in a vertical plane as the horizontal sliding area where the selector locks to set the TPI, stops any movement CLOCKWISE of the selector arm. That is what it is there for.

Again, looking at the gearbox from the lathe headstock end, and trying to rotate the selector ANTICLOCKWISE in a vertical plane, it is only possible to rotate the selector anticlockwise by about 15 degrees after which the Tumbler gear, which is below the input shaft housing hits the front of the gearbox stopping further rotation.

Other than removing the taper pin using a 1" gnome who has strong muscles and can sit in the bottom of the gearbox, I am still at a loss - unless I am missing something!

Thanks for your kind input though Brian. John suggested someone else who may be able to help. I shall follow that up tomorrow.

Kind Regards

David

I have a Myford Super 7B lathe and I am VERY distressed to have broken a tooth from the 39 tooth Tumbler gear in the Norton QC gearbox. (Don't ask it is too painful)!

At the end of a turning job that was on the limit of the Myford's capacity, there was a thump and it was found that a tooth had broken from the Tumbler gear.
The attached photo illustrates the problem of trying to remove the tumbler gear in order to replace with a new gear. The replacement gear wheel is apparently available from Myford, but I cannot see how they could have assembled it in the first place, nor can I dismantle it.

The photo shows the Input shaft of the gearbox withdrawn from the Input shaft housing in order to show the spline on the input shaft which normally runs in the input shaft housing. The Tumbler gear normally protrudes through a slot in the input shaft housing to engage with the spline in the input shaft.

The selector, which is a casting, slides on the input shaft housing to enable the tumbler gear to engage with one of the nine gears for the various ratios. The bottom of the selector caries a short spindle on which the tumbler gear runs and the short spindle is held captive in the selector casting by a taper pin – according to the drawing – it is impossible to see visually.

The task appears to be to remove the input shaft housing, slide the selector off the input shaft housing and then to remove the tumbler gear. However in reality it is impossible to remove the input shaft housing as the selector will not slide off it due to the teeth of the tumbler gear protruding into the slot in the housing. Equally, it seems impossible to remove the taper pin + short spindle + tumbler gear as they are hidden at the bottom of the gearbox underneath the input shaft housing !!

I can only assume that Myford inserted the taper pin through the oil drain hole using a special tool, but extracting it would be another matter and would certainly need the gearbox upside down on the bench.

Has any reader replaced this item on their ML super 7 and can anyone advise me as to how this is possible. I am very distressed at having “broken” my treasured Myford. P L E A S E can ANYONE help me?

Thanks Gray,

Stored away until I get to that part (could be some time).Thanks for your hard work.

Not being good at reading drawings, I imagine that the disengaged detents are horizontal across the sleeve and the forward / reverse are vertical across the sleeve.

Regards

David

Hi Gray,

Glad you approve of my retractable toolpost. - thanks.

Regarding the size, it is exactly as yours except that the body is 54mm wide - sawn from a rough cast? steel elevator counter weight from a domestic lift. The raised tower was added so that it just fit straight on to the toolpost of the top slide and the normal ball handle that I use on my toolpost swung to a suitable position to be out of the way. I adjusted the height of this "tower" by trial and error to get that right and then fixed it to the retractable toolpost with epoxy resin. I do cheat on many occasions.

King regards and all the best for Xmas

David

Gray,

I thought that you may be interested to see my retractable toolpost to your design (more or less).

It bolts straight down to my topslide as I thought that this would be more rigid than mounting in another toolpost.

Now back to viewing the videos of your clutch in action!

Regards

David

The photo on the ML7 is a mock up, but the metric thread was done on the Super 7.

Brian

I now use your 33 and 34 tooth gear method of creating metric threads even though I have a metric quadrant and gears. It is so usefull to be able to do a fine feed and then screwcut a thread without all the faf of mountingthe quadrant.

I shall purchase a lump of tufnol from you when we meet, thanks.

David

Graham and Brian,

I obviously need to wait until Ihave seen the unit in real life when I visit Brian in the new year, as I am having great difficulty in visualising the operation fully at present from just viewing the drawings. I have sent off for an aluminium billet and was wondering how thick the tufnol should be for the two idler gears (25 Teeth and 30 teeth ?). It would appear that the answer is 1" thick.

I must be getting senile as I have had problems visualising it all in my mind and I can usually see quickly how machine parts interact. One problem is that one photo that I have been studying is on a machine that has DAG Browns metric quadrant fitted and that is even more difficult to see.

I look forward to seeing your machine Brian and thank you for your offer to loan the cutters. I shall be very careful with them.

By the way Graham, I have just completed the retractable toolpost from your book and it works well.

Kind regards and thanks to all for the help.

David

Hi Brian,

I was about to source and purchase a billet of aluminium for the main body of the device. I do not have a "tame" supplier of aluminium and wanted to order it so that I am ready to go when I have seen your modified device. From Graham's book, the finished overall slab of aluminium needs to be 125mm x 62mm x 25mm.

I presume that modifying the design to incorporate your modification will not require a larger block for the body. Can you confirm this please. On the pictures that I have seen, the modified part is hidden.

I am posting this on the forum thread in case it helps others.

Kind regards and all the best for Xmas

David

I have a Myford Super7B with QC gearbox and powered cross slide.

Lathe no SK156253
Gearbox QC155983 (in case this makes a difference)

I am wishing to make a screwcutting clutch accessory as designed by Graham Meek and to this end I have bought both Graham Meek's book "projects for your home workshop" and Brian Wood's book on "Gearing of Lathes for Screwcutting" - both of which are excellent reference books.

Graham Meek's book shows the attachment REPLACING the standard Myford cluster reversing handle and therefore leaves the reversing cluster permanently engaged when the lathe is used for non-screwcutting operations.

I see pictures of Myford Super7s with a Graham Meek style clutch unit, but with a modified cluster reversing mechanism in the position of the standard Myford design i.e. with two levers, one for operating the cluster gears and one for operating the "Meek" dog clutch. such a unit is illustrated in Brian Wood's book Fig.1.9 where he calls it "Graham Meeks reverser modification"

One thread on this site quotes Ken Willson (KWIL) as being the person to contact regarding possible drawings or details of this mod, but I have been unable to find a link to him.

Please could Graham Meek, Brian Wood, Ken Willson or anyone else give me any help as I wish to create the screwcutting dog clutch unit whilst retaining the reversing cluster gear unit to enable complete disengagement of the screwcutting gear chain. I hate running a noisy gearbox drive when it is not necessary.

Has any reader of this thread completed this mod and are there any drawings available showing this mod of Graham Meeks excellent design?

David Haythornthwaite

THank you Jason,

I have now seen the photos in Ken's album. I shall start a new thread as you suggest.

Regards

David

I have a Myford Super7B with QC gearbox and powered cross slide.

Lathe no SK156253
Gearbox QC155983

I am wishing to make a screwcutting clutch accessory as designed by Graham Meek and to this end I have bought both Graham Meek's book "projects for your home workshop" and Brian Wood's book on "Gearing of Lathes for Screwcutting" - both of which are excellent reference books.

Graham Meek's book shows the attachment REPLACING the standard Myford cluster reversing handle which leaves the reversing cluster permanently engaged when the lathe is used for non-screwcutting operations.

I see pictures of Myford Super7s with a Graham Meek style clutch unit, but with a modified cluster reversing mechanism in the position of the standard Myford design i.e. two levers, one for operating the cluster gears and one for operating the "Meek" clutch. such a unit is illustrated in Brian Wood's book Fig.1.9 where he calls it "Graham Meeks reverser modification"

One thread on this site quotes Ken Willson (KWIL) as being the person to contact regarding possible drawings or details of this mod, but I have been unable to find a link to him.

Please can Graham Meek, Brian Wood, Ken Willson or anyone else give me any help as I wish to create the screwcutting clutch unit whilst retaining the reversing cluster gear unit to enable complete disengagement of the screwcutting gear chain. I would hate running a noisy gearbox drive when it is not necassary.

Has any reader of this thread completed this mod and are there any drawings available with this mod?

David Haythornthwaite