ML7 Topslide limitations

[Mike PooleParticipant @mikepoole82104]

The ML7 and ML7R topslide does not allow a greater than 65 deg rotation as standard. Is there a classic work around for this problem that I have missed, converting to the S7 assembly is an expensive solution.

Mike

Edited By Michael Poole on 08/12/2013 15:37:21

[Mike PooleParticipant @mikepoole82104]

[old AlParticipant @oldal]

you can rearrange the position of the two clamp bolts to get more angle. You have to lift the topslide off to move the bolts. Bit fussy, but it can be done

[Mike PooleParticipant @mikepoole82104]

Hi Al,

Even if I remove the swivel boss I can not find a position where two bolts can pick up a tee slot because the slot in the top slide base is wider than the cross slide.

Mike

[old AlParticipant @oldal]

Hi Michael

I will have to have a look tomorrow. I have had to do something similar, I just cant remember!

Have you got reverse on your lathe?

Alan.

[Mike PooleParticipant @mikepoole82104]

Applying a bit of lateral thinking I think my vertical slide has some possibilities, swing it to a horizontal position and angle the base to give required facing angle, bit of a fiddle to set tool height but for a one off it's not too bad. Maybe the S7 slide conversion is the only practical solution.

Mike

[anthony smith 4Participant @anthonysmith4]

TO ALLOW GREATER ROTATION OF TOP SLIDE MAKE A SUB BASE OF 3/8 THICK PLATE ABOUT 4.5INS SQUARE WITH A HOLE BORED TO SUITE TOP SLIDE SPIGGET. FIXED TO CROSS SLIDE WITH COUNTERSUNK SOCKET SCREWS MILL CURVED SLOTS TO SUITE TOP SLIDE FIXINGS.IT WILL THEN BE NECESSARY TO USE SMALLER TOOLS

[John Stevenson 1Participant @johnstevenson1]

When I owned a ML7 some years ago I moved the topslide round to the maximum position before the handle fouled the cross slide then worked out decent position where it had plenty of room and drilled and tapped two 1/4" BSF holes.

Worked for me but I dare say the flat earth society would have a baby because I drilled a Myford.

Sorry they are not something to be prayed to every Sunday, obviously Myfords cocked up or people would not need to modify the machine to do what it should have been designed to do.

[Andrew Moyes 1Participant @andrewmoyes1]

Ian Bradley in Myford ML7 Lathe Manual shows a solution using a sole plate interposed between the top slide and cross slide. The down side is that it reduces the size of tool that can be used to about 5/16".

I vaguely remember using a tool mounted on the swivelling vertical slide to get around the problem. I can't remember now how I did it – perhaps this will jog someone else's memory. Will post again if it comes to me!

Andrew M

[Andrew Moyes 1Participant @andrewmoyes1]

I remember now. It was the very first thing I made when I bought an ML7; a Stuart centrifugal pump. I thought it would be an easy first project until I needed to take a facing cut across the blades. They are required to be at a slight angle, not possible with the standard topslide. The solution was to use the vertical slide with its table parallel to the axis of the lathe. The top of the vertical slide was rotated slightly towards the headstock by the required angle and the tool was mounted in a vice on the slide, pointing towards the headstock.

Andrew M

[BubbleParticipant @bubble]

Hello Michael

This solution was described by a Mr Beecroft in ME in about 1955

It works fine for screwcutting but watch-out for excessive tool overhang on the top slide which can give an upward force on the assembly.

A refinement would be two long tee-nuts in the cross slide slots, with the two side- bars attached to them with studs, this would provide vertical location.

Jim

[Mike PooleParticipant @mikepoole82104]

Thanks for the input gentlemen, it would seem that Johns solution of drilling the cross slide would be the most convenient on a regular requirement to use these small angles. The vertical slide solution that Andrew proposed is the one I shall use for the one off job I have in mind as it is a quick and dirty setup with no need to make anything. I will probably get round to making a sub base but as I find my Dickson tool post most useful and the sub base would negate its use this would only be fitted on demand. Looking at drilling the cross slide for Johns solution there is not much room to drill without being very close to a tee slot so although I could live with two neatly tapped holes if the tee slot broke this would annoy me forever like drilling holes in the table on a drilling machine or milling the table on the mill or drilling a machine vice.

Mike

[Mike PooleParticipant @mikepoole82104]

While I was typing, a solution like the one Jim has just posted came into my mind, it must be the power of suggestion at work. With the refinements Jim suggests this could well be the top answer for a leave it in place answer, it would only need to be removed for travelling steady fitment.

Mike

[RobboParticipant @robbo]

Further to Bubble's post, this is Mr Beecraft's original drawing. Just for fun.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

Hi Michael P ,

There is a completlely alternative solution possible using copy turning methods .

Mount a true bar slant wise on bed , arrange a roller follower on cross slide and just copy the angle of the bar onto the workpiece .

Needs a bit of bias loading to keep roller engaged otherwise no problems at all .

Works for curved surfaces like buffer heads as well .

Regards ,

MikeW

[anthony smith 4Participant @anthonysmith4]

RE MR BEECROFTS DRAWING THIS DOES NOT APPEAR TO PREVENT THE TOP SLIDE FEED DIAL FOWLING THE CROSS SLIDE DIAL.THE SUB BASE OF 3/8 THICKNESS WILL PREVENT THIS .THE PLATE SHOULD BE 4.75" SQUARE AND NOT 4.5" AS I SUGGESTED

[Alan JacksonParticipant @alanjackson47790]

I have just added some photos of a Lever Locking Top slide conversion for a Myford ML7. I made this a few years ago. I know as John S. has just referred to that Myford owners do not like to modify their machines but in my opinion it is well worth doing. I have a Colchester Chipmaster lathe with a similar conversion and would not like to go back to the original arrangement trying to access nuts in slots filled with swarf etc.

Alan

[BubbleParticipant @bubble]

Anthony

True, I can "only" go to 80 degrees. I did say it was fine for screwcutting.

In 50+ years with an ML7 I have never needed to go "squarer", that's what the cross slide is for!

I think the loss of 3/8" height is a bigger limitation, especially with quick-change toolposts.

Jim

ps please take your caps lock off!

[Mike PooleParticipant @mikepoole82104]

Thankyou gentlemen for all your contributions, I will most likely use more than one solution as there are pros and cons for all of them, Michaels copy attachment could be very useful with suitable templates for large radius curves and other forms.

Mike

[chrisdavenportParticipant @chrisdavenport]

Tried Andrew M’s solution using a vertical slide.  The only thing that needed to be made was a suitable attachment to hold the tool.  It then worked well.

Chris

[Mark RandParticipant @markrand96270]

What I did, when I had an ML7 with the original cross and topslide, before inheriting the family long bed ML7 (with the S7 topslide), was to use a vertical slide to mill a couple of lengths of square bar into T bars which would span the cross slide with a bit of overhang on each side. Then have a couple of bits of flat bar with a 1/4″ BSF tapped hole in them that could take holding down bolts and clamp the topslide to these bars running alongside the cross slide. It worked perfectly well, but did need the capability to make the long T bars (flat bar in the T slots could be used at a push, but would be a bit more springy)

 

Sorry about the convoluted post. Valentines day shared bottle of Bailey’s is to blame 😀

[Alan JacksonParticipant @alanjackson47790]

I have shown & described this before.  It really adds to the vesatility of operating the lathe if you have a lever locking topslide. The photos show an ML7 cross slide that has been modified(shreik horror) by plugging the centre hole and adding 3mm deep shallow inverted vee grooves along the top of the cross slide. The modified  ML7 topslide can be moved and locked at any angle anywhere on the cross slide

 

[Michael GilliganParticipant @michaelgilligan61133]

I wait in eager anticipation … for the forum to display the image of Alan’s top-slide modification.

MichaelG.

[Speedy Builder5Participant @speedybuilder5]

A couple of these should sort the problem out

[Nigel Graham 2Participant @nigelgraham2]

I’d be reluctant to remove the boss on the underside of the slide, for obvious functional reasons (let alone sacrilege!)

Adding tapped holes to the cross-slide saddle could work but would attract swarf, so would need plugging when not in use.

‘

The Beecroft method avoids those problems but the intermediate plate approach is structurally more sound. Its disadvantage (reduced centre-height) can be alleviated to some extent by using a thinner plate with a stiffening rib along each side that drapes down the side of the cross-slide: e.g. from 3/8 down to 1/4 or even 3/16 inch. Bore the centre to take the top-slide boss.

In that regard, Mark’s modification to the Beecroft design is the best of these three options.

.

The problem of the handles fouling at extreme angles might be solved (I have not tried this) by locking the cross-slide at a suitable position then removing its handle and screw. You might need use some deft calculations if working to a step rather than full-diameter facing.

.

I like Michael’s copy-turning suggestion for the reason Mike Poole advances. To give the positive tracking Mr. Poole queries, a straight conical-facing template could be a round bar taking a simple linear-bearing follower (a plain brass bush should be ample). For curves and compound shapes, use a pin or roller follower running in a channel in a plate or flat bar.

 

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