Making replica wooden knobs on a lathe
 

There was an article In the Spring 2017 BVWS Bulletin on an American 'Bestone' radio by Stef Niewiadomski (known on this forum as 'Saddlestone Man'). If not rare, the radio is certainly uncommon. Unfortunately, one of the three original wooden knobs was damaged, so Stef had fitted a set of three alternative wooden knobs, it being unlikely that an original knob would ever materialise.

Over the years, Stef has been a prolific writer (still is!) in the Bulletin and other magazines such as Radio Bygones. I’ve enjoyed reading his articles and built a capacitor reformer that he designed, so as a small gesture of appreciation for his efforts I got in touch to say that if he sent me the damaged knob, I'd have a go at making him a set of three replicas.

I'll say right away that the process is time consuming and a labour of love, involving a number of processes over a period of several hours, so I'm not in a position to make knobs to order, but given that quite a lot of forum members seem to have lathes, yet might not have considered using them to turn replica knobs, I thought it might be helpful for me to explain how I went about it.

Accurate measurements are called for, involving lots of stopping and starting of the lathe as the work progresses. As the knobs are sited close together on a radio, any slight differences will be immediately apparent. If knobs are in natural wood rather than painted, due to variations in timber grain and colouring, there's little prospect of just making one replica to exactly match the original, so really, a full set needs to be made.

The processes involved are:

• Turn a wooden square to a round spindle, 5mm larger in diameter than the knob.
• Part off a wooden blank from the spindle for each knob.
• Make a brass insert on a metalworking lathe for each knob, drilled out to the diameter of the radio control shafts. In my case, the insert needed to be 12mm outside diameter, drilled ¼” bore.
• Mount a wooden blank in the woodturning lathe and use either a 12mm Forstner bit, or end mill in the tailstock, rotating the chuck by hand while advancing the bit into the blank, not going any further into the blank than necessary. Don’t use an engineering drill as it may penetrate too far into the blank, being pointed at the tip.
• Coat the brass insert with two-part epoxy cement and with the wooden blank still in the lathe chuck, force the brass insert into the wooden blank with the tailstock.
• Make a metal mandrel on which to mount the blank when turning the blank to shape on the lathe.
• Drill and tap the blank and the mandrel 4BA and use a 4BA brass grub screw to mount the blank on the mandrel, placing the mandrel in the chuck.
• Turn, sand and finish the replica knob.
• Remove the knob from the mandrel and fit the knob on the radio control shaft using the 4BA grub-screw.

I had the damaged original knob from Stef to hand so was able to compare various hardwoods to try to get a reasonable match. Iroko and mahogany were not a good match, but English walnut seemed quite close, so I went with that. I drew a sketch of the knob with the critical dimensions and given that the largest diameter was 30mm and the height was 25mm, I turned a spindle 35mm diameter from which I parted off three blanks 30mm long.

The knobs required a 12mm diam brass insert drilled 1/4" for the control shafts of the radio, 16mm long and tapped 4BA for mounting the knobs on the shafts. To ensure that when mounted on the shafts of the radio the knobs would be exactly concentric and true, I turned mandrel on my metalworking lathe with 1/4" shaft for each knob, on which to mount the wooden blank in the lathe chuck for turning.

I turned the brass inserts, roughing the outsides with a junior hacksaw while the inserts were on the lathe, so as to provide a good key for the two-part epoxy adhesive when the brass inserts were glued into the wooden blanks.

The only complication in completing the knobs was that eight notches had to be milled out around the perimeter and I don't have a milling machine. I tried a number of techniques using a router jig and a Dremel in a jig, but not to my satisfaction, so in the end I had to get a chum to mill the notches for me on his monster Bridgeport.

It occurred to me that replica wooden knobs could be turned to mimic Bakelite for some radios, so I later made two replica black knobs for an Ekco A22 - the larger being the tuning knob, the other - with a 'tab' on it - being the volume control on/off knob, (identical to the wave-change switch knob). I'll cover that in another post.

The aim in woodturning is to ‘sand the shape of the wood’ – not to ‘sand the wood to shape’ or sharpness of detail can be lost, so it’s important to keep the turning gouges sharp and to get a good finish ‘off the tool’ to minimise sanding. I gave the knobs a coat of shellac sanding sealer to seal the grain, then a light sanding, firstly with 220 grit, then 320, 400 and 600. (There’s no possibility of skipping and grades - say going from 220 to 600). I finished them on the lathe using shellac 'friction polish'

Not all knobs will lend themselves to wooden replicas, especially if they’re engraved with lettering or have intricate designs and fancy milled edges, and admittedly it’s quite a palaver. It takes hours rather than minutes to create a knob, involving the use of a metalworking lathe as well as woodturning. But that said, if a replacement knob can’t be sourced, for those with the equipment, skill and time, it provides a solution – in my case at minimal cost as the materials were all to hand. True, it’s time consuming, but we’re hobbyists doing what we do for fun and a sense of achievement, using our leisure time for enjoyment – not to make a living. What’s more, here in Yorkshire, ‘summat for nowt’ has a certain appeal!

As I said earlier, I’m unable to make replica knobs as a service to others, but I hope this rather lengthy post and the pictures might be of interest, use and even inspiration, to those who are equipped with lathes, but perhaps hadn’t considered using them for this sort of application.

Hopefully, the pictures might make things a bit clearer.

Pic 1 is the damaged original knob.
Pic 2 is a sketch I drew to show the critical dimensions.
Pic three, a couple of brass inserts turned and roughened up.
Pic 4, three walnut blanks with inserts fitted, and three mandrels turned from scrap alloy bar on which to mount the blanks for turning.
Pic 5, one knob turned and sanded, ready for the perimeter grooves to be milled.

Some more pics in the next post.

Re: Making replica wooden knobs on a lathe
 

Here are a few more picks of the replica wooden 'Bestone' knobs that I turned.

First pic shows three knobs awaiting milling. (I made a fourth in case of mishaps!).
Second pic is my engineering chum doing me and Stef a favour by milling the grooves in the knobs on his monster Bridgeport milling machine.
Third pic is of four completed replica knobs plus the damaged original.
Fourth pic, which Stef kindly sent me, shows the replica knobs mounted on the Bestone radio.

Hope that's of interest, and maybe some use to someone out there.

Re: Making replica wooden knobs on a lathe
 

Outstanding!
Graham

Re: Making replica wooden knobs on a lathe
 

Brilliant, well done David they look excellent on the set.

Andrew

Re: Making replica wooden knobs on a lathe
 

As I mentioned in my first post, while turning the replica wooden knobs for Stef's Bestone radio, It occurred to me that replica knobs to mimic Bakelite could be turned for certain radios, so I later made two replica black knobs for an Ekco A22 - the larger being the tuning knob, the other - with a 'tab' on it - being the volume control on/off knob, (identical to the wave-change switch knob).

As these were to be sprayed with black ‘ebonising’ spray – a speciality paint for woodturning - I cut the blanks cross-grained on my band-saw from beech, which is close-grained hardwood, so sands very smoothly. My aim was to make them look almost indiscernible from black Bakelite. I used my own brown A22 knobs as a pattern. The technique was similar to turning the Bestone knob, without the complication of having to get a good match to the original grain and colour, and didn’t involve any milling of grooves. The smaller knob needed a ‘tab’ to be made and to be neatly glued into a slot cut into the skirt of the knob.

As before, I gave the knobs a coat of shellac sanding sealer to seal the grain, then a light sanding to 600 grit. I gave them a coat of hi-build auto primer and a final sanding before a couple of coats of black ebonising spray. I was pleased with the end result and think they’re a good match for the originals.

Pic 1&2 are my sketches of the large & small A22 knobs.
Pic 3 is a blank cut on the band-saw for the large knob.
Pic 4 shows the blank in the chuck with a packing piece behind, trued up ready for drilling for the brass insert.
Pic 5 shows the chuck being rotated by hand, with a 12mm end mill in the tailstock to mill the blank to the correct depth for the brass insert.

Some more pics in the next post.

Re: Making replica wooden knobs on a lathe
 

A few more pics of the A22 replica knobs.

First pic shows the large A22 knob mounted on a mandrel in the chuck, taking shape.
Second pic, large knob almost finished.
Third pic shows finished large knob alongside my original brown A22 Bakelite knob, and the mandrel on which the knob was turned.
Fourth pic shows the small knob taking shape on the lathe.
Firth pic is the small knob slotted, into which a tab shaped as the original was then glued.

In the next post I'll show the finished knob.

Re: Making replica wooden knobs on a lathe
 

Last pics!

First pic is two original brown Bakelite knobs from my Ekco A22 alongside the two replicas.
Second pic is the original small knob alongside the replica black one.

In fairness to my chum who milled the 8 notches on the four 'Bestone' replica knobs for me, the last pic shows a knob on its mandrel in the chuck of the Bridgeport milling machine, on which the last notch had just been milled.

I'll be taking the knobs to Hornsea radio rally tomorrow morning, where my chum John ('60old john' on the forum), will do a quality control inspection for me!

I hope the thread is of interest, not too far off topic away from the electronics aspect of the hobby, and might encourage others who are suitably equipped, to try their hand.

Re: Making replica wooden knobs on a lathe
 

There was a lot of [justified] excitement when 3D printing became available David and parts for radios could be fabricated in plastic or metal [as an alternative to the resin mould technique]. These hand crafted replacements for wooden originals, though, are in another league-amazing:clap:

Dave W

Re: Making replica wooden knobs on a lathe
 

Thanks for reading guys, and for your kind comments.

Yes Dave, 3-D printers seemed to offer much promise but have rather gone of the radar screen of late.

From my very limited knowledge, looking at items in exhibitions that have been 3-D printed, I think the main shortcoming is the standard of finish, but in many cases, that may not matter as appearance will take second place to functionality. But knobs of course are on display, so getting a finish that's very close to the original may pose quite a challenge.

I was recently at the V&A where they were demonstrating a range sophisticated 3-D printers, way beyond the realms of DIY jobbies.

They were making all manner of complex objects, large and small. The larger ones used large nozzles to build the object quite quickly, then to get a good surface finish, switched to finer nozzles. However, even with the fine nozzles, the end result had small and distinctly discernable ridges where the filament was applied. I'm not sure whether - if knobs were made using 3-D printing - the plastic can be sanded and polished with burnishing cream so as to look like original Bakelite or plastic knobs - say like those for the Ekco A22 for instance.

The other issue might be matching the filament to original colours, though I guess most plastic radio knobs were made in fairly standard colours such as cream, green red, white, black, brown. If a full set of matching knobs is made, they don't of course need to be exactly the same colour and finish as the originals - only to each other.

for me to get into that, the equipment would need to be so simply to use that I'd just need to point a scanner at an object and say 'make one just like that'. :-)

The other option is casting in resin - I've had a dabble at that, making moulds from original knobs using Alginate, but so far, with little success.

Re: Making replica wooden knobs on a lathe
 

Morning David.
As always first class work and an outstanding finish on the radio knobs. I bet the knobs put a smile on stef face

Kevin:thumbsup:

Re: Making replica wooden knobs on a lathe
 

An excellent and impressive standard of workmanship, as ever.

This struck a resonance with me(pun slightly intended) with the Audiophool thread. Many years ago someone was trying to sell wooden knobs with amazing sonic properties. They were ridiculed for charging $485 for each one. But looking at David's description of the work involved and considering overheads and profit margins etc., maybe that isn't an excessive sum.
I can't find a web link to the original part, but here's a contemporary comment:
http://bobbyowsinski.blogspot.co.uk/...#axzz4vZNXwuMv

I note this is a thread about wooden knobs, not about audiophoolery.

Re: Making replica wooden knobs on a lathe
 

You have done a fantastic job of making those wooden knobs! I have a little lathe in the workshop (Micro-lathe II), but I lack the skills to make anything complex on it yet. I have used it to turn some wooden back plates for an old bakelite light switch though! It would probably help if I had more than one tool for it, and a better chuck.

I have made silicone moulds of knobs before, and successfully cast replacements, the difficult part being matching the colour and surface finish. All the knobs on my black and chrome Ekco AC76 are resin replacements, unfortunately missing the chrome inserts! For the resin I used 'David's Fastglass' from Halfords, you can buy the resin and hardener separately, on it's own it sets a sort of translucent pink colour, but you can add colouring to the mix.

A place I used to work had a 3D printer, it worked by building up layers of support material and some sort of plastic resin that it cured with UV light as it printed it. You were then left with the part you want encased in the support material which you had to clean off. The thing used to stink awful whilst printing! We would all have headaches by the end of the day being stuck in the same room as that... The parts that came off it were quite good, it all depended on the setup, if you wanted it quickly, you compromised on the finish quality. It was mostly used for making prototypes, and the occasional production parts that were hidden inside the main products (cable clamps being a favourite!). The major downside to the machine was the cost! it was about £16K, and the cartridges of material were stupidly expensive too, and they had a use by date.

Regards,
Lloyd

Re: Making replica wooden knobs on a lathe
 

Very professional finish, but I guess you're a professional !

I heard Gerry Wells say in a TV programme once 'we've knobs for every kind of set, and if we don't have one, we'll make one'. I always wondered how he made his.

Re: Making replica wooden knobs on a lathe
 

I was amused by the comment "I can get you a wooden knob that performs way better for only $250".

I bet he could!

Re: Making replica wooden knobs on a lathe
 

No - I'm a hobbyist Kevin - I don't do anything for money.

But there are two definitions of 'amateur':

One is someone who is 'amateurish' and not able to turn out work to a professional standard.

Another is someone who works to a high standard, but not as a profession.

I strive to work towards the latter.

The one thing that hobbyists have in their favour is that unlike professionals, they're not constrained by time pressures, and if hobbyists don't enjoy what they're doing, they can stop doing it. Professionals, on the other hand, have to work because they have to eat!

Re: Making replica wooden knobs on a lathe
 

Seems to mean the cheapest way these days, there is the profession of cost reduction of course.

Once the design department where I worked once (there where two of us!) was called, in writing, "A bunch of armatures".

Re: Making replica wooden knobs on a lathe
 

The original meaning of the word 'Amateur' is one who does something for the love of it. It comes from amo, amas, amat and all that oft-chanted latin.

Someone making something for the love of it might just do a better job than someone who was just doing it for a job. Not that many of us have th luxury of a job we're passionate about.

'Amateurish' is really a compliment, if the speaker was aware of what he was saying.

For a $485 wooden knob, individual pieces of hardwood would have to be auditioned. There might only be one bit good enough in an entire tree. Those microvibrations can be little devils.

There looks to be a lot more work in David's knobs than in the $485 job. Perhaps a lot of the money goes in hiring people who can write the advertising copy without dying laughing? (Shades of Monty Python's 'funniest joke in the world' sketch)

David

Re: Making replica wooden knobs on a lathe
 

David,

Absolutely stunning workmanship!

Jac

Re: Making replica wooden knobs on a lathe
 

Wonderful work on the knobs David, very very impressive.

Re: Making replica wooden knobs on a lathe
 

Stunning, David!

Re: Making replica wooden knobs on a lathe
 

I'd say you were an amateur, David, and not a professional for the simple reason that I consider your skills superior to the many professionals I've met in my time. You are one of the relatively few highly skilled and talented people who set the bar for the rest of us to attempt to emulate.
I won't add 'well done' because it's been said by many on this thread and lots of others that feature your work. I will say 'keep up the good work', knowing you are sure to.
As Argus points out, very impressive. As always.
Regards
Tony

Re: Making replica wooden knobs on a lathe
 

Nicely done David, a dentist friend of mine used to make copies of knobs with plaster of Paris and cast replacements in what he called "Dental Acrylic" (Norwegian = Tannlegeakryl).
Cannot ask him these days because he died nearly ten years ago now, but I do have one or two of his repair jobs and attempts at creating CRT bases for WWII German radar equipment tubes. I think that it is a question of experimenting more than anything, the alternative would be what?

Re: Making replica wooden knobs on a lathe
 

Many thanks to those who have read this thread for their kind comments.

My purpose in starting the thread wasn’t so much to show off my handiwork, as to outline an approach and explain to others who may have small lathes but rarely use them, and who may not have considered their lathes to make replica knobs if needed. Though it’s flattering to receive so many kind comments, I'd like to emphasise that the level of expertise required to make replica knobs isn’t very high – just basic woodturning and metalworking skills, well within the scope of anyone who is of a practical bent and possesses lathes and a few turning tools.

Sometimes people ‘inherit’ a lathe, or might buy one on impulse but never use it. A small, simple metalworking lathe in particular is very useful in radio restoration for making things such as spacers and shaft couplers, and a woodturning lathe can be useful for turning plastics as well as wood. A lathe can also be useful for accurately tapping a thread on a rod or bar internally or externally, by either holding a die or a tap in the headstock or tailstock with the work-piece in the other end, and turning the chuck by hand. The thread will be far more accurate and concentric that it would if the tap and die were hand-held with the work-piece in a vice.

But to get back to making wooden knobs, if the knob is going to be sprayed - as the Ekco A22 knobs were, then kiln dried beech is ideal, being close grained and knot free. Luckily, beech in spindle form sufficient for several knobs is readily and cheaply available in the form of 35cms long x 2cms diameter pastry rolling pins from Wilko, currently for £1.25:

http://www.wilko.com/baking-utensils...m/invt/0078397

Alternative a search on e-bay for ‘English Beech wood-turning spindle blanks’ will find plenty of suppliers, then the square can be turned to round on the lathe to the desired diameter in a matter of minutes. Cross-grained beech say 40mm thick for larger diameter knobs such as the large A22 tuning knob that I turned can be had from hobbyist timber suppliers and sawmills.

As to the woodturning tools that I used to make the knobs, there were only three – a roughing gouge to turn the wood to the required diameter, a ‘parting tool’ with which I did most of the turning, and a round nosed ‘scraper’ to create the dome shapes. The tools are shown in the picture below.

To turn a length of square timber to round, the wood can be held ‘between centres’.

The easiest way to find the centre of the timber at each end of the blank is to use a ‘centre finder’ to mark the wood with as pencil, then prick the centre with scriber. Having mounted it between centres, with the tool-rest close to the timber, just below centre line with the roughing gouge angled upwards, the square blank can quickly be turned to round. (More experience turners may use a skew chisel, but lesser mortals such as me, steer clear of that!). Here’s a link to a centre finder, which can be used on square or round timber. (They can be found on e-bay):

http://www.axminster.co.uk/axminster...-finder-340146

Having turned the wood to a spindle of the desired diameter, a parting tool is used to slice off a knob blank of the required length into which a hole can be drilled on the lathe to accept the brass control shaft insert – in my case, the insert was 12mm diameter with a 6.4mm diameter hole through the centre. The blank is then fitted to a mandrel made to suit and mounted in the woodturning chuck to shape and finish the knob, as outlined in my earlier posts.

Pic 1: Centres marked on square spindle ends using ‘centre finder’
Pic 2: Roughing gouge, parting tool, round-nosed scraper.
Pic 3: A live centre and four pronged centre, which have 'Morse tapers' and fit into the headstock and tailstock of the lathe.
Pic 4: End of spindle marked for four-pronged centre.
Pic 5: Beech square blank held between centres, ready for the toughing gouge to turn the square blank to round.

A bit more info and a few more pics to follow.

Re: Making replica wooden knobs on a lathe
 

I'm very aware that this is a vintage radio forum - not about woodturning, which is well catered for on other forums. However, I hope this isn't too far off track and is sufficiently relevant to the hobby to be worth the space, given that most of us often find cabinetry restoration (veneering, re-finishing etc), and sourcing knobs is often problematical, which is where I came in with this thread.

A question that often crops up in woodturning, circles is ‘what speed should I run the lathe at?’ The answer is that the faster the turning speed, the cleaner will be the cut, and the smaller the diameter of the wood, the faster the lathe speed needs to be as there’s such a small amount of timber passing the tool with each rev when it’s of a small diameter. There’s a loose ‘rule of thumb’ formula for calculating the speed at which a woodturning lathe should ideally be run, and that is: ‘Diameter in inches x RPM = 6,000 to 9,000’. So for example, a 10 inch diameter bowl blank should be run at a speed of 600 – 900 RPM. Most turners will start off at a slower speed when the blank is first mounted as it will be out of balance until trued up with a roughing gouge.

Using this formula, it follows that a 2” diameter spindle would have a turning speed of 3,000 RPM, and a 1” one a theoretical speed of 6,000 RPM -, well beyond the capacity of the lathe, so most turners would run the lathe at perhaps 2,000 - 3,000 RPM.

At 3,000 RPM, a 1” diameter spindle would have about 3” of timber passing the tool for each rev, so that would be 9,000 inches of timber per minute passing the tool (about 750 feet). A 10” diameter bowl with the lathe running at 600 RPM will have 30 inches of timber per rev passing the tool - 18,000 inches (1,500 feet) per minute. Thus, the smaller the diameter of timber, the faster the lathe needs to spin at to get a good clean cut. At too slow a sped, instead of the tool cutting the fibres, it tears them, then it’s necessary to resort to sanding by working through the grits to perhaps 600 grit for a good finish. The sharper the tools, the faster the speed, the cleaner will be the result, and less sanding will be needed.

For sanding, the lathe speed needs to be reduced to 250 RPM or so and the sandpaper not held in one place or it will score rings around the timber.

Just to finish off, here are a few more pics regarding the process of creating a blank to make a knob:

Pic 1 Parting tool ready to part off a knob blank.
Pic2: Blank almost parted off.
Pic 3: 4-prong centre removed from headstock by tapping it out with a bar.
Pic 4: Chuck fitted to the lathe headstock, with blank in place ready to be trued up.
Pic 5: Using a 12mm end mill (not a drill) to mill the hole ready for a brass insert to be glued in.

I hope these notes will give an indication that no exceptional skills are called for.

There are countless woodturning videos on youtube showing spindle turning – some better than others.

Have fun!

Re: Making replica wooden knobs on a lathe
 

Hi David,

Only just noticed this thread today or I would have replied earlier.

All the knobs you have produced are superb but the A22 knobs are something else - not at all easy to get the tab on those correct, but yours are perfect!

Excellent David - a really first class result!

Kind regards

Re: Making replica wooden knobs on a lathe
 

Thanks for your kind word Robert, but as I've outlined in the last two posts, it's really quite basic turning for anyone with a modicum of woodturning and metalworking skills, given a bit of care and patience. If it doesn't work out first time, so what - the materials are very cheap and the pay-off is that we can make knobs that we'd otherwise stand little chance of finding at any cost. Being well thought of by our chums is an added bonus!

I did have a go at casting knobs in a range of materials but with limited success. Basically, because I was trying to use a 'home-brew' casting jig to accurately locate the brass insert in the centre of the knob and couldn't do that to my satisfaction. I'm going to revisit it and try just using the jig to make the alginate mould into which to pour the casting medium, then when it's set, I'll drill the cast knob in a 'jam chuck' on the lathe, made to suit each knob to enable the brass insert to be fitted concentrically, as with wooden knobs.

Not every knob will lend itself to a cast replica, (or a wooden one, come to that), but many will. I've spent more hours fruitlessly searching for knobs at the NVCF etc, than I ever would in gearing myself up to cast one, or even a set so they all match each other and look as original as possible within the limitations of what we have at our disposal. If the outcome is successful, I'll start another thread on that.

Re: Making replica wooden knobs on a lathe
 

Excellent work. I would love to have a decent sized workshop to accomodate the necessary machine tools. I used to really enjoy my time at college using the various lathes and milling machines. Very inspiring work David and thanks for the helpful advice.

Regards
Symon

Re: Making replica wooden knobs on a lathe
 

Like others, I'm late in coming to this thread but am struck by the excellent results. Really impressive work David. I'm very jealous of your skills.

Well done!

Peter

Re: Making replica wooden knobs on a lathe
 

Excellent work David .

Re: Making replica wooden knobs on a lathe
 

I had the pleasure of seeing the Ekco knobs in the flesh last week. They look even better than the photos here show. A truly excellent job and a work of art! Well done David.

Peter

PS: the Pye PE94MBQ works fine.

Re: Making replica wooden knobs on a lathe
 

Well done David , looks very impressive...it's all about the passion isn't it not the money...great work

Re: Making replica wooden knobs on a lathe
 

It's really kind of fellow forum members to make such encouraging and flattering comments, which it's nice to be on the receiving end of. But without wishing to sound falsely modest, I can only reiterate that anyone who has a basic woodturning and metalworking lathe and a few tools, together with an average level of skill could attain the same results. Obviously you have to be fairly accurate to get the dimensions correct, for which a cheap pair of digital calipers is useful, but it's hardly precision engineering. I'm sure that anyone who does possess and use a lathe would agree with those comments.

To my mind, in all that we do in life, for us to make much of a success of anything, we need to be 'pernickety' - a word sometimes used as a term of derision - 'excessively precise, fussy, overly attentive to detail', obsessive even. But if we're not all of those things, I think we're on a slippery slope, in the wrong hobby and it becomes a chore - not a pleasure.

Of course you do ideally need an original knob as a pattern - if only a damaged one, and it may be that if replicas of Bakelite knobs are required, especially if the knob has features that aren't easily reproduced in wood, such as milled edges, then casting would most likely produce a better result. I'm going to have a go at that and if the results are worth sharing, I'll post a thread on it.

In some instance, depending on the colour and texture, maybe 3-D printing would be a good option, but that requires considerable investment in equipment and expertise.

At risk of turning the forum into a back-slapping 'mutual admiration society', 'high-fiving' each other, the level of resourcefulness, skill and investment it time to achieve the accomplishments is the posts below is way up in the stratosphere, far out of sight of my replica knobs!

http://www.vintage-radio.net/forum/s...d.php?t=111951

https://www.vintage-radio.net/forum/...ad.php?t=47965

http://www.vintage-radio.net/forum/s...d.php?t=114857

http://www.vintage-radio.net/forum/s...d.php?t=138304

That's where 'pernickety' - in the nicest sense of the term - gets you!

Re: Making replica wooden knobs on a lathe
 

Thanks Peter - glad the knobs passed their quality control inspection!

The Pye was my first radio, bought in 1958 as I recall when I was 19, and a Short Wave Listener. I've still got some broadcast station QSL cards that I received!

Re: Making replica wooden knobs on a lathe
 

I am in awe of anyone who can create such precise replicas.

Maximum respect!

I've seen websites of people using 3D printers to make figurines and they lament the rather coarse finish.

One person found a solution - he suspended his printed items in acetone vapour (no direct liquid contact or the item melts!)

Timing is important but get it right and the figurines acquired a glossy finish.