mini overhead drive – opinions please

[Roderick JenkinsParticipant @roderickjenkins93242]

Just to add to the general confusion, here's a couple of photos of my overhead drive arrangements:

The drive belts are either heat 5mm heat joined from Hemmingway or 6mm hollow urerhane joined with a little ally gizmo. The motor is 1/6 hp induction with the starting capacitor and reversing switch incorporated in the black control box. Bars are 1/2" mild steel joined with old chemical laboratory "scaffolding" connectors and the upright sits in an ally fixture bolted to a cross slide T slot. It drives an Arrand milling spindle which, in this case, is mounted on a base that fits into the S7 topslide fixture and keeps the axis of the spindle at the same height as the lathe axis.

Rod

[BazyleParticipant @bazyle]

Perhaps we should make more use of our lathes as a powerfull variable speed drive source, and the leadscrew provides an extra low speed drive. A pulley held on the chuck could drive a machine temporarily moved in front. Cunning positioning of a lathe next to a mill would provide a table feed via universal joints off the leadscrew.

(HSE whingers look away now) On a forum somewhere recently I saw a photo of a rope drum on the chuck, a rafter fixing and some pulleys lifting the lathe itself.

[TerrydParticipant @terryd72465]

Posted by Roderick Jenkins on 14/10/2012 12:11:50:

Sorry to join the conversation so late, it took me some time to find and scan the illustration. To get back to ADY1's original question, a variation of the image above might meet the requirement . It's taken from John Jacob Holtzapffel's Principles and Practice of Ornamental or Complex Turning. It was reproduced by Tubal Cain in Milling Operations in the Lathe which has a lot of good advice on the subject of milling spindle drives. Instead of the spring stantion, modern round flexible drive belts should give a good enough drive.

Rod

As has been said earlier in this thread, the Hotzapffel (and other makers) take off (to drive the overhead shaft and cutting frame was powered by the machine spindle, but Ady has moved on from that now towards a seperate but still overhead drive utilising a small electric motor.

You could have foound the image more easily by following the links in earlier posts.

Best regards

Terry

[Roderick JenkinsParticipant @roderickjenkins93242]

Terry,

I'm not sure Ady has moved on from his original idea.  And yes, if you wade through the OT website as I have just done this illustration is there.  Just trying to be helpful.

Rod

 

Edited By Roderick Jenkins on 14/10/2012 15:26:18

[TerrydParticipant @terryd72465]

Hi Roderick,

Ady was enthusing about an overhead drive he had seen on Chris Heapys old site. That utilised a seperate motor ,and I think that these days it is the way to go now that powerful low voltage motors are easily available and relatively inexpensive. It obviates the need for expensive and somewhat dangerous overhead shafting with all of the noise and bulk that entails. Ady did ask for opinions, hence the title hence my opinions

The links to the ornamental lathes etc are on the first page of this thread.  You might like to look here if you are interested in the Ornamental Lathe and Rose engine.  The pdfs are well worth reading.

Best regards

Terry

Edited By Terryd on 14/10/2012 16:44:57

[Sub MandrelParticipant @submandrel]

Hi Terry,

Not completely convinced by computer PSUs. They can be fiddly to get working (you need to ground ceryain wires if I recall correctly), they can overvolt if unloaded so ideally tehy need a dummy load on any unused outputs. Finally as SMPSUs expecting non-induictive loads, care would need to be taken when driving a motor. A SMPSU designed to drive stepper motors may be more suitable (as designed for a continually varying and inductive load), so one out of a big printer or photoco[pier, perhaps?

That said, I have managed to get a compter PSU working as a stand alone, but never used it for anything more exciting than lighting up a car headlight as a test.

Neil

[TerrydParticipant @terryd72465]

Later PSUs do not have the need to be grounded or have a ballast resitor inserted. If you bundle the output cables they are capable of high current and very stable outputs. I am in the process of developing a design for a variable voltage, fixed current output additional circuit to be fed by one of these, I will report on the results at some time hence.

Regards

Terry

[Ady1Participant @ady1]

I've been goofing about and working most of the weekend but done a couple of things, getting bits and bobs

It's going to take a while

I've found a couple of rare photos of a proper Drummond setup

Getting the detail of these old units can give you ideas of your own

[Ady1Participant @ady1]

Moving in the horizontal plane was sussed out on night 1 by using the barrel system shown in the diagram above and a swinging drive motor

 

Moving in the vertical plane is going to take a bit of thinking time, I want to maximise the simplicity of the design if that's possible

 

edit

My goal is to use the main lathe motor to do both tasks, just swap the belting over

Minimum amount of bits, maximum simplicity to make, maximum versatility kind of thing

All ideas are welcome, I'm not the only user out there who might get some inspiration

Edited By Ady1 on 15/10/2012 01:34:21

[TerrydParticipant @terryd72465]

Posted by Roderick Jenkins on 14/10/2012 15:18:55:

Terry,

I'm not sure Ady has moved on from his original idea. And yes, if you wade through the OT website as I have just done this illustration is there. Just trying to be helpful.

Rod

Hi Rod,

You are quite correct I was misled by Ady's post on the 12th at 10:25 when he said:

"Generally speaking, it is more convenient to use a dedicated motor to drive the Overhead; and it can be easily arranged that the weight of that motor tensions the belt

Instant solution number 1"

I foolishly assumed that he intended to use a dedicated motor for the drive and not a common drive from the lathe motor. If that had been the case, with modern motors and the light power that attachments generally need, a simple overhead using the weight of the motor as counterbalance would have been a very simple solution. My friend Eric Whittle (of V8 fame) used the system successfully on his Myford.

As you will know, the reason that overhead shaft drive was common in the past was the development from the treadle lathe where there was only one power source available i.e. the foot, and industrial practice where the only sources of real power was the watermill or steam engine. The need for overhead shafting declined when small electric motors became available. Personally I fail to see a real reason to use such an archaic system except as a museum exercise, but I could be mistaken, I often am .

Sorry if I caused you concern, it was not intended,

Best regards

Terry

Edited By Terryd on 15/10/2012 07:33:16

[Michael GilliganParticipant @michaelgilligan61133]

Ady,

You may find some further inspiration on the Treadleit website.

… [my apologies if that duplicates anyone's previous postings]

MichaelG.

 

P.S.  The complication, with adopting the Drummond layout, would appear to be that the lathe was already driven via an overhead shaft: Wheras yours is not.

Edited By Michael Gilligan on 15/10/2012 08:32:01

[Ady1Participant @ady1]

The overhead drive was dropped from the 1930s and 1940s because of advancements at a time when energy resources were dirt cheap and "unlimited" and available materials were limited but plentiful

 

Nowadays even a hobbyist like me has access to lathe belting which is almost indestructible and plastics which were unobtainable

The overhead drive drum for instance can be made from a good plastic drainpipe or gaspipe

In the 1950s it was far heavier wood or metal and a major bit of kit

 

So I'm revisiting old ideas with new materials where possible here

(Thanks for that Treadleit link btw)

 

Edited By Ady1 on 15/10/2012 10:08:11

[Ady1Participant @ady1]

And learning as I go…

How many of us know what a goniostat is?

I'd never heard of it until 5 minutes ago

**LINK**

It's used for cutting gem facets, but was adapted for tool tip grinding purposes by the old lathe doods

(You won't even find that word in Wiki)

[IanTParticipant @iant]

If anyone has a copy of Edgar Westbury's "Milling in the Lathe" (mine was published in 1948) he gives quite a lot of variations on 'overheads' and discusses their applications and merits in some detail.

The reason i mention this, is that he also describes a "Dwarf" overhead gear for driving vertical spindles (as mentioned by Ady1). He describes it as follows;

"in which the need for the standards and countershaft are eliminated, drive being taken direct from the treadle, through jockey pulleys mounted on brackets attached to the lathe bed. While these variations offer advantages for certain applications, they are not universally adaptable as the standard form of overhead gear and are comparatively little used"

I don't have a scanner handy but the set-up requires vertical uprights (on the bed) to which are attached arms at 90 degrees on which the drive belt pulleys run. The belt is then looped around the milling drive pulley – with the belt running paralell to the bed.before being returned to the treadle drive. I did consider a modern version of this, with an electric motor mounted vertically (and in a corner out of the way) – and two simpler vertical posts (with horizontal pulleys) being used to adjust belt tension. A simpler alternative would of course be to simply mount the motor on a stand behind the device and run a direct belt to the device but this might sometimes get in the way.

I have thought about a more traditional overhead too – but for now, I'm going to try another method suggested by Mr Westbury – the flexible shaft drive. I have a heavy duty one to experiment with – plus a Proxxon shaft/collet chuck combo that will be the basis of my first attempt at some form of light/high speed drilling spindle (mounted on the cross slide or vertical slide) and driven by a Dremel hanging above the lathe.

Regards,

IanT

[Ady1Participant @ady1]

That ornamental turning site is gold dust

Here's one which uses an overhead shaft and also does the vertical with a single overhead drive

Presumably one wheel is keyed and one runs freely (lol)

 

 

That counterweight system lets you use any tension you want

http://treadleit.info/system/files/mainsite/images/0338.jpg

 

 

Edited By Ady1 on 15/10/2012 11:25:35

[Ady1Participant @ady1]

the flexible shaft drive. I have a heavy duty one to experiment with – plus a Proxxon shaft/collet chuck combo that will be the basis of my first attempt at some form of light/high speed drilling spindle (mounted on the cross slide or vertical slide) and driven by a Dremel hanging above the lathe

——

Should be fine for high speed small hole drilling and grinding

My cheapo one failed once I started doing anything which needed torque, bigger slow hole drilling and milling was a definite no-no

gl

[Ady1Participant @ady1]

We're actually nearly there guys, one final solution is required

We need a free running counter rotating pulley to run on the drum, so it works like the last picture I posted

Then we've got the template for an easy to build fixed standing unit, infinitely adjustable for torque purposes which works in the horizontal and vertical

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ady1 on 15/10/2012 10:22:04:

And learning as I go…

How many of us know what a goniostat is?

I'd never heard of it until 5 minutes ago

**LINK**

It's used for cutting gem facets, but was adapted for tool tip grinding purposes by the old lathe doods

(You won't even find that word in Wiki)

Ady,

Glad to see that you are enjoying the journey !!

You presumably have this sussed, but [in broad terms]; a Goniostat positions/holds something at an angular orientation, and a Goniometer measures the angle at which something lies.

MichaelG.

[Ady1Participant @ady1]

I borrowed the family braincell for the last bit.

Looking at the bit of drainpipe it seemed a wee bit cheap and non permanent and wouldn't it be nice to remain faithful to the original Britannia setup on page 2 with a keyed drive wheel etc

I wanted however to keep movement in the x, y and z axis of any attachments so this meant I needed a keyway along the entire length of the drive bar (ugh)

….wouldn't it be nice to have a drive bar which was one long keyway, THAT would save lots of work and fettling and messing about wouldn't it?

Well a visit to B+Q sorted it, so anyone can do this

A metre of 12mm square iron bar was 6.20 and a metre of 7mm square rolled steel was 6.20

I'm not sure which to go with yet, probbly the 12mm, it's much stiffer so will be better for heavier work like milling

 

So that's us sorted chaps, the easy bit is done

 

….just got to make it now…sigh

 

Edited By Ady1 on 16/10/2012 10:05:58

[Michael GilliganParticipant @michaelgilligan61133]

Ady,

Here is another useful link for you.

… and it's worth browsing his site.

The full text of the Lukin Book is there

MichaelG.

 

[added second hyperlink]

Edited By Michael Gilligan on 16/10/2012 10:15:08

[Ady1Participant @ady1]

Well it's been a while since I revisited this thread but I've been waiting for a shaper to come along to make my ME work easier. Took me 2 years to get one and I've been doing various bits'n'bobs meantime

Got the shaper at last…then puppy wuppy gets ill and decides to shuffle off her mortal coil so after all that I got about a month of free time before puppy wuppy 2 is due at the end of this week so I thought I better write this up… until I get to the next instalment in 2 years time…

The support bars are about a fiver a pop fencing from B+Q, as is the square drive rod running along the top, they are bolted onto the lathe with 10 or 12mm B+Q threaded rod, there's a big lug at the headstock end of a M-series lathe which makes things miles easier.

The tailstock end is supported by the bottom half of a spare tailstock I had.
Onto this has been placed a 1 inch thick lump of a broken lorry leaf spring I found by the road, banana shaped at first but the shaper flattened it out nicely to take a broken bit of cast iron vice and a lump of scrap from the box, all secured together via more 12mm threaded bar from B+Q

The ebay bearings are mounted inside some scrap gas pipe I half-inched from outside a neighbours house when a plumbing job was being done there.

Mounting the bearings to the support bars for the drive shaft was going to be a bit fiddly and it was at this point I broke out the 40quid Lidle welding unit I got 2 years ago.
After a bit of practice at birds nesting I tacked each pipe to the support bars, aligned them properly then welded them as best I could.

About 3 hours fiddly ME work was done in 15 minutes with that welding kit and it all seems to be nice and solid
The bearings were tapped back into the pipes and then the 2nd part of these pipe bearing carriers screwed home.

An old lathe belt cone was fettled into position at the headstock end and some old used bits of plastic lathe belting were candle welded back together to make the big drive belt

It runs rather nicely, whirring away with only a little vibration from the too stretchy belting,

Torque at the drive bar is moderate to low, only mild drilling to 6mm max I would say but this is mainly due again to the stretchy belting.

It's going to be fun experimenting with this thing, it definitely has a lot of potential.

[Ady1Participant @ady1]

The biggest surprise of all was the welding kit which was a pleasure to use and saved me a lot of messing about

[Raymond Sanderson 2Participant @raymondsanderson2]

Posted by Ady1 on 15/10/2012 00:48:04:

I've been goofing about and working most of the weekend but done a couple of things, getting bits and bobs

It's going to take a while

I've found a couple of rare photos of a proper Drummond setup

Getting the detail of these old units can give you ideas of your own

I know its an old thread/post but love the set up great work. How's it going? What have you used it for?

[HopperParticipant @hopper]

Wow, that is intriguing. Watch your flapping shirt sleeves though! The old Drummond looks classic in the original black. I wish I had not painted mine Myfraud grey now.

[Author]

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