Mystery change gears

[Martin-Sy]

3/4" bore:
48-127t
85t
85t
80t
75t
70t
70t
65t
60t
55t
48t
48t
43t

1.12" bore:
152t
152t
127t

Well that's an interesting assortment. Unfortunately not quite the full standard metric set, but with some duplicates and some extras.
For the metric threads on the plate you're missing: 50T and the 72T with external keyway.
Extras you have: 85 x 2, 43, 152 and the 48+127

The extras: one of the 85T and 43T I'd be interested in.

Nothing back from @fizzy and I've been trying to remember who else on here has a CVA @graffian ?

 

[fizzy]

Well that's an interesting assortment. Unfortunately not quite the full standard metric set, but with some duplicates and some extras.
For the metric threads on the plate you're missing: 50T and the 72T with external keyway.
Extras you have: 85 x 2, 43, 152 and the 48+127

The extras: one of the 85T and 43T I'd be interested in.

Nothing back from @fizzy and I've been trying to remember who else on here has a CVA @graffian ?

Will take some piccies tomorrow.

 

[Martin-Sy]

Will take some piccies tomorrow.

Sorry @fizzy, i had forgotten you were in hospital yesterday. Hope it wasn't too painful.

 

[6ply]

Well that's an interesting assortment. Unfortunately not quite the full standard metric set, but with some duplicates and some extras.
For the metric threads on the plate you're missing: 50T and the 72T with external keyway.
Extras you have: 85 x 2, 43, 152 and the 48+127

The extras: one of the 85T and 43T I'd be interested in.

Nothing back from @fizzy and I've been trying to remember who else on here has a CVA @graffian ?

Feel free to make me an offer.

 

[Martin-Sy]

Thanks @6ply . How does £20 each sound?

 

[6ply]

Thanks @6ply . How does £20 each sound?

Low?

 

[Pete.]

Martin you turn the blanks and I'll glue the teeth on them for you.

 

[Martin-Sy]

OK, I'll pass on these then.
Thanks anyway.

 

[Martin-Sy]

Martin you turn the blanks and I'll glue the teeth on them for you.

Thanks for the offer @Pete. I think these two are part of the BA set, and TBH I'm not sure that I'll ever want to single point BA.
OTOH you never really know, so your kind offer will be kept in mind (Not that my mind retains much these days!).

 

[fizzy]

Sorry @fizzy, i had forgotten you were in hospital yesterday. Hope it wasn't too painful.

Due in Tuesday cheers!

 

[fizzy]

Yes, I'm confident that's a CVA metric set ... possibly more than the basic set too.
The give-away is the gear with the external and internal keyway.

Here's mine:

View attachment 376080
Top L to bot R: 48, 48, 50, 152, 55, 60, 65, 70, 72, 75, 80, 127.
With the exception of 127 and 152 all are 3/4" bore with a 3/16" keyway.
Top left are two 48T and also have an external keyway so they can be made into a compound pair with the 127.
The 72T (bot row 2nd from left also has this feature.

This is from the parts manual.

View attachment 376081

The thread plate on the machine:

View attachment 376082

As @Agroshield has spotted the 152T (used as an Idler) is different by 1 tooth from the Monarch 10EE set. No idea why other than someone at CVA couldn't count
As it's only used as an idler it doesn't make any difference.

It would be interesting to know what the tooth counts for all yours are.
You have an assembled 127+48 which is much less faffing than mine where you need a short length of key to lock the 48 and 127 together.

As @Pete. has said - these are quite expensive to source.
There are others on this forum with CVA's .... @fizzy for one

Martin.

Here are mine. Needed de rusting. Why does citric always leave a dull black/grey finish? How do I get them shiny again?
Anyway mine seems to be similar to yours. Just missing the 80T. I have 2x 127 one is attached to a 48. Also have a separate 48.
Do I need the 80?

 

[Martin-Sy]

For the coarser metric pitches the compound needs to be 127+72. I can see you have the 72 (1 in from the left it the last picture) and an unattached 127 so you're OK here.
The 80 is needed for 0.4, 0.8, 1.6, 2.0 and 4.0 mm pitches (assuming you have the later feed gearbox without 11.5 TPI and with 19TPI).
There should be some 'top-hat' bronze bushes too. 3/4" OD.

 

[fizzy]

Here is the plate from mine.
Can you show me pics of the bushes and give me dims please? Should be easy enough to make?
Looks like the 80 is pretty essential.

 

[Pete.]

You can get by without the 80. The most likely thread you'd want to cut would be 0.8mm which is the pitch for M5. You can achieve that by using the 60T gear and selecting 30TPI on the box.

 

[Martin-Sy]

Here are the bushes @fizzy .
Dims:
Overall length 1.245"
Hole 9/16" to fit on quadrant studs.
Large end 1-5/16" dia for 0.333" long,
Remainder 3/4" dia to be a running fit inside gears.

Mine are worn and I will be making some new ones.

@6ply : there may be some of these lurking in that box.

 

[fizzy]

Here are the bushes @fizzy .
Dims:
Overall length 1.245"
Hole 9/16" to fit on quadrant studs.
Large end 1-5/16" dia for 0.333" long,
Remainder 3/4" dia to be a running fit inside gears.

View attachment 376375

Mine are worn and I will be making some new ones.

@6ply : there may be some of these lurking in that box.

Thanks - phos bronze best I assume? What about brass?

 

[Martin-Sy]

My new ones will be from PB1 - so yes, a bronze would be best but you only need them if you're not using the standard imperial setup.
The two imperial idlers run on ball races.

 

[Agroshield]

Here are the bushes...

Just to cover possible variations between machines or in manufacture, please could you describe what the length of the smaller diameter part should be in relation to the thickness of the gears. In other words, when the nut and washer is added, should they clamp the bush to the stud but leave a small amount of endfloat on the gear? The alternative, which might not be correct, is that when secured the gear and bush would be squeezed together.

It would be bad if he made the bush to dimension and then it did not work with his gears. Understanding the principle of what it does means he can verify that the measurement is correct for his setup.

 

[Martin-Sy]

Just to cover possible variations between machines or in manufacture, please could you describe what the length of the smaller diameter part should be in relation to the thickness of the gears. In other words, when the nut and washer is added, should they clamp the bush to the stud but leave a small amount of endfloat on the gear? The alternative, which might not be correct, is that when secured the gear and bush would be squeezed together.

Good point @Agroshield . From the dims 1.245 - 0.333 = 0.912.
The width of a compound pair (it's actually the width of the boss of either the 72 or 48) are, in my case, 0.903 and 0.905 respectively.
So the bush is clamped when the nut is tightened, but the gear pair is free to rotate on the bush. This tension also locks the bolt in its adjustment slot.

This is a metric setup
70 --- 127+72 --- 152 --- 48

Good luck for tomorrow @fizzy .

 

[fizzy]

Good point @Agroshield . From the dims 1.245 - 0.333 = 0.912.
The width of a compound pair (it's actually the width of the boss of either the 72 or 48) are, in my case, 0.903 and 0.905 respectively.
So the bush is clamped when the nut is tightened, but the gear pair is free to rotate on the bush. This tension also locks the bolt in its adjustment slot.

View attachment 376478
This is a metric setup
70 --- 127+72 --- 152 --- 48

Good luck for tomorrow @fizzy .

Cheers both!