Hello

[Nick PassmoreParticipant @nickpassmore75850]

Hello Paul.

Another Black Country boy here. Born in Gornal and grew up in Kingswinford. Been in exile in London since the late 70s.

Also not a model maker. I did once make an electric guitar (the best part of 50 years ago now) but I never got the neck straight enough to be able to tune it . . . .

[SillyOldDufferModerator @sillyoldduffer]

Posted by Paul Mallen on 18/08/2020 13:27:38:

…

RS are selling just a 20T cog for £27.44

One quote for a “4 off batch” of worm drive & gear =£120

Another for 11 pieces – which is 5 worm drives & 6 cogs I think) = £980

and I can buy a bag of 30 18T cogs off eBay for £7

what am I missing or not understandining here?

Only that RS sell Retail and are always relatively dear. But their is stuff is reliable, well above the worst ebay can do.

Cheapest approach if possible is to use standard mass-produced components sold by the million. Getting anything bespoke is maximum price territory, the difference between Saville Row and George at ASDA. Basically, it's very expensive to make a prototype, but once a production line is running selling prices drop massively because the development costs are shared by huge numbers of purchasers. If a product costs £1M to develop for one customer he'd better be stinking rich. If the same product can be sold for £5 a pop to 10,000,000 customers everyone is happy.

A small workshop makes sense when small numbers of non-standard mechanical items are needed, but the materials, tools and skills all have to be obtained.

Dave

[Paul MallenParticipant @paulmallen24579]

Hi Nick, good to talk to another local lad, well local-ish

Sounds like you needed a truss rod in it mate, but if it made a noise & enjoyed it then thats all that matters

Hi Dave, thanks for the answer – yes i totally understand where you are coming from, the bit i don't understand is that its two components that are used in a multitude of things and the quotes I've had are from companies who just specialise in worm gears, so one would think that these are readily available off the shelf items & sold by the bucketload, not some kind of tech that would get an F1 engineer excited – to be honest, if i could buy them for a fiver a pair then i'd not think twice about machining them….

At this rate i think my best bet is to buy a set of tuners off eBay, the 4 for 8 quid ones, strip them, rob & modify the parts to make my own, i honestly never thought in a million years that a 12mm cog & an M8 x 12mm drive would potentially cost more than the whole guitar – & i'm not cheap lol…..

I'll try to sort out some pics to illustrate when i get home as i think my terminology is seriously at fault here judging by some of the quick searches im doing…….. sorry folks

Edited By Paul Mallen on 18/08/2020 17:15:41

[brickyParticipant @bricky]

Welcome paul ,you will find this forum is a mine of information, all willing to help.I too trained at nights at the Newark Violin School and made seven violins being a luthier is so relaxing.

Frank

[haroldParticipant @harold]

Hi Paul,

As a luthier you'll have heard of David Rodgers' 'tuning machines' ie machine heads. They're a real joy to use. Have a look on his website maybe for some ideas :Rodgers website

Welcome to MEW!

Regards,

John

[Paul MallenParticipant @paulmallen24579]

Hello Frank, thanks for the welcome and its good to see so many people on here that sort of do what i do! it is very relaxing 7 you get to play the end result!!

Hello John – thanks for the welcome and that link as I've never heard of him before – some really beautiful work on there & i will dig in further when i get 5 mins spare. I tend to specialise in making electric basses so I'm only familiar with makers like Schaller, Grover, Hipshot & the like when it comes to tuners, but its really good to see someone specialising in another one of guitar makings dark arts which not too many people are willing to enter into….

[Howard LewisParticipant @howardlewis46836]

Belated reply; sorry

Do not buy change gears for the lathe from RS. They are likely to be Module gears, and Metric, and unsuitable.

Also, being modern the pressure angle will be 20, not the 14.5 used by Myford. Gears with different pressure Angles will not work well together.

If the RS gears provide the required ratio, and fit into the available space, you can use them on the guitar.

For the guitar, I would imagine that the gear and worm would need to be less that 1 Mod, possibly 0.5, to keep the sizes small?

Myford gears are 20 DP (Diametric Pitch) If you count the teeth and add 2, and then divide that number by 20 you will get the figure for the OD, in inches.

Everything on the ML4 or its smaller sisters will be Imperial. (Gib adjusters may be BA, which is a sort of metric, but not the same thread form )

The gears for your ML4 are 5/8" bore, as are those for the later ML7 and its descendants.

The difference is that your gears are driven or compounded by means of 3/32" pins in drillings that go part way through the gear. The Gears for ML7 use a key and keyway instead.

At the risk of telling you what you already know, changewheels should run from 20T to 65 or even 75T in 5T increments. There may well be an gear with a strange number of teeth, such as a 38 or a 63, intended to allow metric threads to be cut, using the 8 tpi Leadscrew.

In standard trim, I think that there should be two 20T gears, but a third is useful. Together with an extra 60T, it allowed me to set up a fine feed on someone else's ML4. ( I don't own one! ) The extra 60T was ex ML7 so had to have a 3/32 hole drilled in it for the driving pin. For this, I drilled right through one of the existing 20T gears and used this as a jig to put the hole on the correct pitch circle.

The final set up was: Diving Collar+20 on the Mandrel,:60/20 on first stud, : 65/20 on the second stud: 60+Driving Collar on the Leadscrew. You set up in this order so that there is no risk of the first and second 20:60 meshes fouling and locking things solid.

This gave a feed rate of 0.00427"/ rev. And the Saddle moves towards the Headstock. Using two studs is imperative unless you have the optional tumbler reverse. You can use just an idler to reverse the rotation, without altering the overall ratio, if you need. If you have gears with more teeth, you can set up finer feeds, if the banjo slot is long enough (I had to make up studs, since they were missing, and to lightly fettle the slot the slot in the Banjo to get the meshing somewhere near correct ) so it may be possible with the genuine article.

To set the mesh, I run a piece of card, about 0.003" thick, into the mesh before tightening the studs into place. This provides backlash which minimises wear and noise, which will happen without it.

HTH

Howard

Edited By Howard Lewis on 19/08/2020 13:21:58

[Paul MallenParticipant @paulmallen24579]

Howard thank you again for taking the time to explain that, I do actually follow what you’ve written so that’s pretty good for me
The tuners tend to be roughly 25mm x 12mm x 12mm on the back of the headstock as there is limited room for them to sit (I don’t like big bulky headstocks so I try to make them as sleek as I can).
I think for now the cheapest & by far the easiest option is to buy cheap tuners, rip them apart to use the drive & gear in my own, when people are charging £27 for one gear & I can buy identical ones with the worm for £2.50 (albeit in a ready built tuner) I think it’s a no-brainer, maybe when I’ve perfected my design I can re-visit looking at making them, but my lathe is seriously not going to help matters so I think it needs to go so I can get something more suitable for someone with my limited abilities – I know the ML4 is perfectly capable but this needs some work that is way beyond my price range & skill level, it’s done what i brought it for which was to just make a few control knobs for the guitar electronics & made it possible for me to prototype a few ideas I had so it’s done it’s job, it’s time to get one that I’ve not got to source missing parts for & can concentrate on learning how to operate it without worrying that I’m about to get speared by something everytime switch it on – one with a mill drill would be good as well.

i just wish I had paid more attention when I brought this one & not been in such a hurry to grab the first one that came up, but it’s taught me a few valuable lessons along the way, I just hope I can shift it & not loose too much on it!

Thanks again for taking the time to explain & enlighten, I really do appreciate it.

[Neil WyattModerator @neilwyatt]

Hi Paul,

I think even most 'boutique' builders buy in their tuners, so no shame in doing so or repurposing parts from other tuners.

I'm sure this has occurred to you but the 'feel' of the tuners is really important to many buyers, this is generally dependent on the meshing of the gears more than anything else – close enough to minimise or remove backlash without being stiff.

I'd love to see a picture of one of your basses! I've just finished a Harley Benton kit – it was only £77 and I was impressed by it, aside from some slightly out of place screwholes. I want to attempt a ground up build at some point.

Neil

[Paul MallenParticipant @paulmallen24579]

Hi Neil, thank you for the welcome! Yes its been a bit of a bugbear of mine since i started making them about 10 years ago, I strive to build from scratch – i've even made my own truss rods in the past & have had a recent excursion into headless basses – which i like but i'm not too much of a fan of tuning from the bridge if i'm honest, but its something i'm still working on…

Yeah the tuners seem to be even more of a dark art within luthiery itself, & that just makes me want to dive in head first! After all, ive just spent the last few weeks filing lead screws for 3D printers to fashion a worm drive to use in a few prototypes – the bit is well & truly in my teeth!! Unfortunately it seems the worm drive & gear are not as easy as first thought to make – hence me destroying all spare tuners i have to help fashion my own….

My website is here if you fancy a peek, i run the 'On the Bench' page as a sort of mini-blog thing so i generally post what im up tp on there when i can remember to…… I'm making a few stainless bridges at the mo to fit the builds ive got coming up…

Yes there are some really impressive kits about & ive seen some really nice results from them – you always will have to furtle a bit to get things smack on, but if you enjoy the process & enjoy playing it then thats what its all about – just don't end up like me – build one, go to sell it, play it a bit, decide that its not for sale & end up with a housefull of the things

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