Myford ML7 Dividing head attachment

[Robin teslarParticipant @robinteslar]

Hi Myford people

Ive just acquired the above Myford dividng head, what precision! But I am puzzled as to what arbor attachment to use. Ive searched around Myford with no obvious answer. The head has two fixed centres and is obvious intended to use a between-centres arbor with spacing collars and clamping nut. But the nose is the usual 1 1/8 12 tpi Myford to fit a Myford chuck which could then clamp the arbor, but there is not much room and photos Ive seen show a 3ins backplate and maybe a carrier, but I cant find this offer for sale anywhere? So maybe Im barking up the wrong tree. Anyone know how it is done?

Cheers

Robin

[Robin teslarParticipant @robinteslar]

What kind of Arbor to use

[RobCParticipant @robc77385]

Hi Robin,

I have used mine a few times now and although it came with a small chuck mounted on the 'nose', I used my ER32 Collet Chuck instead to hold my arbor. This works nicely as there is less overhang with the smaller chuck diameter and also less weight on the mechanism in general.

I will see if I can dig out any photos of the setup. I am sure I have some, as I was pretty chuffed when I managed to get it all setup and cut a gear for the first time.

Alternatively, I have seen the dividing head mounted up to the left of the headstock, so that it can be used to index the spinlde round for operations that you control on the cross slide, but I have not yet found a suitable way to attach and hold it round there.

Cheers,

 

Rob

Edited By RobC on 30/10/2012 09:33:24

[BazyleParticipant @bazyle]

I think the idea is use either the chuck alone or between centers, not chuck to center. Between centers the carrier is just a standard one and a drive plate is just a chuck backplate.

However as the drive plate does not need any precision like a chuck you can turn it up yourself even if a beginner to screwcutting and it can be aluminium. It makes sense to fit a brass locking screw. For small workpieces with little stress you don't even need to make it threaded – just a close fit over the thread and hold with locking screw. Finally for a quick hack just use a jubilee clip.

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

The general idea was to set it up like a horizontal miller arbour with 2MT taper in socket at one end and centre support at outboard end .

Strangely Myford never provided the arbour but dead easy to make one . You could make a proper arbour tooling set with different size shafts and sets of spacing and locking collars if you wanted to .

Regards ,

Michael Williams .

[KWILParticipant @kwil]

Myford illustrations show clearly between centre on overarm and with the arbour retained in a collet Nose is standard with 2MT, so you can choose, ER adaptor, 2MT arbour, Myford collet whatever you like.

Bazyle, this is a precision dividing head, properly fitted drive arrangements lead to better concentric accuracy!

[Robin teslarParticipant @robinteslar]

Hi all

I though I was being thick, but it seems to me that Myford stopped developing the Diving head and so never made a milling arbor kit to suit, they don't even suggest what to do. I will opt for the between centres arbor and backplate system. Collets (er25 adaptor £100, collects £145) is a bit steep for me.

Ive never cut a gear this way before, but ive hobbed a few in my time.

PS Rob

How do you find the Trileva shown in your photo?

Cheers keep turning

Robin

[MICHAEL WILLIAMSParticipant @michaelwilliams41215]

2 MT and various collet holding methods are roughly equivalent and all satisfactory .

For something like gear cutting a between centres arbour and catchplate drive will be VERY much less rigid and may give you problems that you would not have with a more solid mounting .

Regards ,

Michael Williams .

[KWILParticipant @kwil]

Rob, you can make an attachment that enable use on the otherside of the headstock. You need a 2MT arbour with short drawbar and with a split collar to pick on the left hand end of the spindle (I always use it on my Myford S7, it has a nice ground surface here). An adaptor plate with a round bar picks up the overarm hole and at the other end of the plate I have a hole with aligns with the arbour of part of the gear train.

Look at Pic 6 in my album which shows it this way, albeit it is not very well displayed.

[Robin teslarParticipant @robinteslar]

Hi Kwil, great album, though I struggle to understand some of the smart things you are doing just from the photos. Presumably you have posted description of what you are doing elsewhere on the board but I cant access them?

Perhaps you could post some links

I dont quite follow what you have done with the Myford divider on pix 6?

Cheers

Robin

[KWILParticipant @kwil]

Rob,

See your PM box.

The Dividing Head is mounted on the left hand end of the spindle. The chuck holds a new toolslide base for a Toolslide which holds a DRO scale inside. (see pic 7).

I do not normally post descriptions in a Forum Thread which relate to a picture, but merely use the photos to explain something. Early photos in the album explain the inside pads etc for a boiler for Locomotion for example.

K

[RobCParticipant @robc77385]

Thanks for the description, Kwil, but I think I need a photo to visualise it properly. I think I get the jist of it, however.

Robin, the Tri-Leva is fantastic, but I don't fancy trying to fix it if it goes wrong! It makes the whole user experience so simple. Once I can work out how to engage the back gears, I should be good.

Rob

[BazyleParticipant @bazyle]

Back to the start of the thread. When this dividing head was launched Myfords were sold with the motor as an extra let alone a chuck. Only industrial users would be expected to buy a dividing head and they would have no trouble making the arbours etc so the market for accessories was minimal.

[Cornish JackParticipant @cornishjack]

RobC – the TriLeva is an excellent device, even more so when coupled to a VFD 3 phase motor. Probably with that configuration you could dispense with the back gear.

One point to bear in mind – if you ever need to fit a new belt, you really ought to do all three at the same time – the hassle getting one fitted is a bit of a pain so do them all while it's in pieces!!

Rgds

Bill

[Robin teslarParticipant @robinteslar]

Hi all

I came across this site relating to speed controlled motors on Warco

**LINK**

I infer that a vfm shouldnt be regarded as a replacement for a back gear. Trying to do heavy slow work would likely overheat the motor. This site advocates the use of a computer fan to assist cooling. Sounds like a smart move for a few quid.

Ive got todo some homework on vfm and stepper motors and their controllers. I only ever did traditional motors at college many years ago. Anyone remeber the Ward Leonard system?

I think a trileva kit went on ebay recently for about £300

Cheers, keep turning

Robin

[KWILParticipant @kwil]

Definately remember Ward Leonard systems? Yes and other  motor generator combinations.

Of course. I certainly use VFD drives on my machines and at low speeds, however there are limits, time at such low levels needs to be watched, a hand on the motor from time to time can be useful. I screw cut at 200rpm, but do not expect to take really heavy cuts at such speeds when in a high speed pulley setup but with the VFD turned down. One needs to be sensible about load.

Edited By KWIL on 30/10/2012 22:52:12

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