Retaining Change Wheels on stud

[BazyleParticipant @bazyle]

It seems to be common to whinge about the time taken to change change wheels for fine feed or screwcutting. What’s the best design for holding the change wheels onto the studs to simplify it? (lets take the washer as a given).

Mostly studs are threaded so it is a fiddle with spanner and nut.
Then some have small screw, typically slot head not cross head so screwdriver has to be aligned.
The early Drummonds have a hole down the stud with special push-in pin – very quick but perhaps tended to fall out so not perpetuated.
I have one with a cross drilled hole and a split pin. I think an R-clip here would be a quick solution.

I guess if all studs were level at the left hand end or could have a make-up sleeve that projected a little if needed then a plate held against all ends could quickly hold or release them while also providing HSE cover.

Any good ideas?

[DC31kParticipant @dc31k]

I think I have seen somewhere the use of a C-shaped washer.

I cannot remember if it seated in a groove in the stud or if it was retained by a socket capscrew (whose head is smaller than the stud diameter).

A fiddly variation on this would be a spring and top hat washer under the capscrew head and making the leading edge of the C-washer wedge-shaped. Then it would be tool-less operation. The spine of the C-washer could also be enlarged within reason or have a bent tag added to make it grippable.

[not done it yetParticipant @notdoneityet]

Raglans had the clever idea of the C washer – so easily removable after loosening the small headed stud (originally, but replaced with cap-screws, as above).

[cogdobblerParticipant @cogdobbler]

Never had a Drummond push-in retainer fall out in decades of using them. Quick, easy and reliable in my experience. Much better than the fiddly little screws and washers on the later Myfords.

[JasonBModerator @jasonb]

The Chinese have cracked it. C shaped washer that just slip into a croove on end of the stud, held by gravity. The top of the stud is square to take a spanner so easy to reposition the stud

[bernard towersParticipant @bernardtowers37738]

If people find that a fiddle I wish them luck when it comes down to makig parts that are sub 1mm!!!!

[Charles LamontParticipant @charleslamont71117]

There is part of a changewheel stud mod I am trying out sitting in the lathe chuck right now. The trouble with the Myford S7 arrangement is that when you undo the nut the whole lot of seven parts comes apart in your hand, well mostly, I often also get bits in the swarf tray or rolling under the bench. I want the stud and the oilite sleeve to stay put while the gears were removed.

I have made one trial where the stud is replaced by a cap-head and a separate tee-nut in the banjo. The head of the cap head is turned down and then sleeved. The sleeve is externally threaded and shouldered for a nut and C-washer.

This is OK, but removing the C-washer only allows me to pull the gears off the keyed sleeve, which is retained by the nut. Putting them on again is a pain because the sleeve is inaccessible and wants to rotate, so it is difficult to line up the keyway in the gear. I only found this out when I tried it.

The next effort, a work in progress, replaces the nut and C-washer with a one-piece flanged nut. The nut will need to be removed to take the gears off complete with the sleeve, but the stud and oilite bush will stay put.

I won’t really know if I like the arrangement until I have tried it for a few months.

[Charles Lamont]

On Charles Lamont Said:

 

…it is difficult to line up the keyway in the gear.

How about filing the begining of both the key and the keyway at 45 degrees, to provide a lead in (a funnel).

Put a paint mark on the gear and sleeve in line wiht the key/way so you can start with them in the approximate correct relationship.

[Russell EberhardtParticipant @russelleberhardt48058]

Never had any problems with my made in England Atlas lathe in that respect.  Decent size 3/8 BSF nuts not at all fiddly, big enough to find easily if dropped.  I keep an old open ended spanner handy to just nip it up lightly.

Russell

[DC31k]

On DC31k Said:

On Charles Lamont Said:

 

…it is difficult to line up the keyway in the gear.

How about filing the begining of both the key and the keyway at 45 degrees, to provide a lead in (a funnel).

Put a paint mark on the gear and sleeve in line wiht the key/way so you can start with them in the approximate correct relationship.

I am not going to doctor the keyways in all my changewheels, but I will think about rounding the end of the sleeve key. Dabs of paint is an idea, thank you, but don’t think they would help much in this situation.

[Dave SParticipant @daves59043]

Not especially helpful, but I just change the lever from ‘Feeds’ to ‘Threads’.

The change wheels are only fiddled with on the occasion I want metric rather than imperial from the gearbox.

Love my CVA.

[old martParticipant @oldmart]

The Smart & Brown model A  has a simple system to hold changewheels. The shafts that the wheels fit on are plain with a threaded hole in the end and a countersunk slotted screw is fitted permanently. No need to unscrew more than about 4 turns. There is a countersunk thick washer under the screw which is bigger than the wheel bore and it has a slot cut from the edge to the centre slightly wider than the screw diameter. The washer can be removed without removing the screw.

[JasonB]

On JasonB Said:

The Chinese have cracked it. C shaped washer that just slip into a groove on end of the stud, held by gravity. The top of the stud is square to take a spanner so easy to reposition the stud

Yes, it works well when the studs have a long enough thread to screw into the banjo, have shanks sized to the gears and aren’t made of engineering grade cheese. I had lots of problems with my originals, and when the the threads finally stripped on one I made new ones out of some otherwise unusable AN bolts. Now the gears are in alignment and don’t rattle around, the studs stay tight, and the clips don’t fall out of the grooves.

[JasonBModerator @jasonb]

18 yrs on and mine are all fine.

But now they will sell you a lathe with ELS so no studs are noise to worry about😊

[Nick WheelerParticipant @nickwheeler]

Yes, I’d buy one without a second thought. It’s about time small lathes were brought fully into the twentieth century

[bernard towersParticipant @bernardtowers37738]

Or the 21st!

[BazyleParticipant @bazyle]

…. and buy a replacement five years later, and another five years after that etc. so let’s stay on topic please.
I found pictures of several lathes with the C washers mentioned, Raglan and S&B, not sure what to look for for the Chinese version.

Also wondering if the sprung ball bearing that retains socket wrenches is a runner.

[Howard LewisParticipant @howardlewis46836]

Ideally, the stud should have an integral threaded stud which is clamped to the banjo with a nut and washer. The gear is retained on the stud by a capscrew and washer.

This is how it done on the mini lathes. A nice simple method, which can easily be replicated, if needed.

Not new; the Myford ML1,2,3 and 4 from the early 1940s used this method.

The gear is retained on the stud, while it is moved to set the mesh with the next gear in the train, before the nut is tighten to clamp the stud in place on the banjo, and the meshing rechecked.

Howard

 

[Speedy Builder5Participant @speedybuilder5]

If you are so worried about using a spanner,  fit an ELS and do away with all those gears!

Bob

[JasonBModerator @jasonb]

I’ll take a picture of my Chinese ones later.

[bernard towers]

On bernard towers Said:

Or the 21st!

As the post after yours shows, that’s a bit optimistic.

[Howard Lewis]

On Howard Lewis Said:

Ideally, the stud should have an integral threaded stud which is clamped to the banjo with a nut and washer. The gear is retained on the stud by a capscrew and washer.

This is how it done on the mini lathes. A nice simple method, which can easily be replicated, if needed.

Not new; the Myford ML1,2,3 and 4 from the early 1940s used this method.

The gear is retained on the stud, while it is moved to set the mesh with the next gear in the train, before the nut is tighten to clamp the stud in place on the banjo, and the meshing rechecked.

Howard

 

Not sure I understand this description, Howard. Where is the nut? Behind the banjo, or between the gears and the banjo, or something else? If behind, it would not work on a Super-7 where the back of the banjo is made hopelessly inaccessible by the dished guard backplate.

[JasonBModerator @jasonb]

Tee nut on the back of the banjo and you don’t need to get a spanner too them, Chinese do it that way.

Here you go video of the retainers on my Warco. Forgot to show that a 10mm spanner fits the square end and is all you need to move the studs. Gears slip onto a bush with integral key locking the pairs together.

 

[Howard LewisParticipant @howardlewis46836]

Charles,

The stud has flats which prevent it rotating within the banjo, the threaded extension carries a washer and nut (On the other side of the banjo). When the nut is tightened, the stud is clamped in position on the banjo (Once the gear meshes have been set).

The outer end of the stud can be tapped to take a screw , setscrew, or capscrew with a washer to retain the gear on the stud. Or it could carry another external thread for a nut and washer.

No big deal, just a simple arrangement!

To help a newbie, I made a stud so that a second compound idler could be used, to produce a fine feed for finishing, on his elderly lathe.

Certainly worked that way on my ML7, so seems unlikely that subsequent models would make it impossible.

Works that way on my later oriental lathe, and on my mini lathe when I had it

People have been using this sort of arrangement for changewheels for 90 or more years, so it can’t be that difficult!

Howard

[Bo’sunParticipant @bosun58570]

I have the same system as Jason for retaining the change wheels on my WM250, and I have to say, I was more than a little dubious about relying on Mr Newton to stop the ‘C’ washers coming off.  However, touch wood and whistle (whatever that means), they’re still in place.  Even if they don’t sit quite vertical most of the time.

[Author]

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