Thread: Cva mk1 help!

Hi all. I have a 1949 cva mk1. It's a direct copy of a round dial 10ee, except for the motor and drive arrangement. The lathe was bought part restored and is not nearly complete, but running it showed that in screwcutting drive the headstock clunked.

Further investigation has shown the revrrse idler is missing teeth.
Does anyone have one or have any ideas what to do?

My guessing is the original will be hardened and profile ground.
I could maybe make one, but it'd never be as good as an original.
This lathe is otherwise perfect and complete.
Thanks.
Ian

If the round dial is like the square dial (likely) the gears are not hardened. The left gear is a 18 pitch and the right gear is a 16 pitch if I remember correctly. The smaller tooth size is because the idler gear is in the gear train and the gear has to be physically smaller. The idler for the left gear would be 18 DP if I am correct. I assume 20 degree helical, that could be determined by the OD.

In any event, Monarch may have a used one at a reasonable price, if not I can make you one for almost as reasonable price.

Thank you for your fast and helpful reply. I have emailed monarch. My gears look as you describe. Am I to assume 14.5 degree pressure angle? Are you uk based? Thanks for the offer to make one. Would it be hobbed ot single tooth cut on a universal? I can do the latter.
Ian

Originally Posted by ir9074

Hi all. I have a 1949 cva mk1. It's a direct copy of a round dial 10ee, except for the motor and drive arrangement. The lathe was bought part restored and is not nearly complete, but running it showed that in screwcutting drive the headstock clunked.

Further investigation has shown the revrrse idler is missing teeth.
Does anyone have one or have any ideas what to do?

My guessing is the original will be hardened and profile ground.
I could maybe make one, but it'd never be as good as an original.
This lathe is otherwise perfect and complete.
Thanks.
Ian

I MAY have one. I'd need the round-dial "EE" number and/or a diameter, width, tooth-count, GOOD photo or the like to sort through a loose collection from a round-dial part-out. Mind - I have two complete Round-Dial, so I can also make sure it IS the right one once pointed in the right place.

EG: have not had to mess with the gears on either of them yet, so am NOT automagically au fait even with WHICH gear we are looking for.

IF I have it, it will be undamaged, and may not even have a lot of wear.

The PO took what HE needed. I just bought and stashed the residue of the part-out so it didn't go to scrap. So I've not inventoried it. Nor had the need to ID what is what.

Shipping to Blighty is not an issue. Cable & Wireless retiree. "We have our ways"



"While you are at it".. sadly, it is common for a gear to lose teeth and damage its mating gears, or OTHER gears in places where the broken shards might stray.

Check that "soon".

You may need more than just the obvious gear. You may have a sprung shaft.

Wow! This would be amazing. I will be stripping the headstock in the not too distant future to remove the gear. The headstock only contains five gears in total. On the spindle nose side (right) the forward gear snd its partner on the driven shaft. On the left,the reverse gear and its idler (beneath and barely visible)plus the partner on the driven shsft. I'll take a few photos inside the headstock, but it'll be a little while before I strip it out. THANK YOU,
Ian

Originally Posted by ir9074

Wow! This would be amazing. I will be stripping the headstock in the not too distant future to remove the gear. The headstock only contains five gears in total. On the spindle nose side (right) the forward gear snd its partner on the driven shaft. On the left,the reverse gear and its idler (beneath and barely visible)plus the partner on the driven shsft. I'll take a few photos inside the headstock, but it'll be a little while before I strip it out. THANK YOU,
Ian

"We'll see". Headstock I have, Illustration in the manual as well. The thing as needs CONFIRMED is that we ARE discussing the SAME gear, and that your one has the same size and tooth-count as our US 10EE have.

We can get factory manuals - by specific S/N - for our Round-Dials from Monarch for a very reasonable fee.

If you have NO such info for the CVA?

Suggest you email Terrie at Monarch and see if you can at least buy the "Operator's Manual" so as to have the illustrated parts ordering portion to better assist in ID and sharing of whatever is the same.

EG: On parts picture E2-A, the relevant reversing subsystem parts are items 28 to 36, with item 32 being "Reverse idler Gear" itself.

I have one. And "not only".

So check ALL your gears AND shafts for damage. If I have them you have "first dibs".

Anything I don't get rid of has to be buried with me.

As I'm meant to be buried at sea?
Help me out.

The ocean ain't but so big, and it might be full of f*****g plastic bags by the time I clock out!

They are 14.5 PA. I have a hobber, but if you have a knee mill, and a universal indexer, and the gears to set up for the proper lead, and a #2 cutter for the DP, you could make it yourself. I have a program that gives 4 gear ratios to 6 decimal places so I can help you with the proper gears.

Anyway, if Thermite has the gears you are good. As I tell potential gear customers, the cheapest way to make a gear is to buy it. Gears are an expensive hobby. Good luck

Again, thank you. I'll remove the gear and hope Thermite has it. I have a B&S universal light with its original accessories, including the gears. I think I can calculate which gears I need, but will ask for help if neccessary. How do you know it'll be a no 2 cutter ? Do you know the number of teeth the gear has? I thought they woild be 14.5pa on a 1949 machine, so nife to have it confirmed. How do I put photos on here?
Ian

For Dp cutters the cutter number goes inversely with teeth number. Module cutters make more sense, cutter 1 is few teeth, cutter 8 is infinite teeth. I made a mistake, I was thinking of the gears on the reverse shaft, which I think are 60 tooth. You mentioned the idler, so it probably will be cutter 3 or 4.

This is from the KBC catalogue, but cutter numbers are listed in many sources.

Bll230. Thank you for the information. I was aware of the involute cutter designations, but unsure of how you knew the tooth jumber!
Thermite. I've emailed you what I know! It is indeed the part you refer to.
Many thanks to all for your help so far!
Ian

Ian,

One of your country mates, Earl Sigurd, posted here that he has a CVA manual:

CVA Toolroom Lathe - Feed Gearbox

Earl has posted here within the last month, so he's still active.

Cal

Originally Posted by ir9074

Bll230. Thank you for the information. I was aware of the involute cutter designations, but unsure of how you knew the tooth jumber!
Thermite. I've emailed you what I know! It is indeed the part you refer to.
Many thanks to all for your help so far!
Ian

Emails are running now, Ian. Looks as if I have all the parts you need and more.

But something else is perhaps possible, and we need more expert input from others:

Givens:

Making a gear from scratch on "basic" equipment is a sore TEDIOUS pain in the anatomy. At best. Helical gears more-so yet.

Cutting "a few" teeth ONLY - two in this case - as a repair? Not as hard.
No need even of a rotab or dividing head.

All one does is FILE a tight-fitting sprag. Then clock the rotation off the UN-damaged teeth. Easier yet? Clamp a MATING gear at near-as-dammit "interference" fit to the good teeth. No other indexer to be fabbed.

No matter the form, the *spacing* can never NOT be "right".

And you set your tool and vet the setup off the UN-damaged teeth as well.
Before cutting "for keeps".

The gear itself is the Dividing Head.

"Page Two"

10EE or CVA, they were born in time of war. One of the most useful of high allloy steels in wartime?

8620.

Called "Ordnance Steel" for good reason. When not the BEST choice of alloy it is usually "close enough" to be "good enough" for most any purpose where a 'steel' can serve at all.

Including rather decent gears.

And it is weldable. So are even LESSER "high alloy" steels

More so than ever with modern TiG and a dab hand's expertise. Hired. No need to become he who has the knowledge.. and applies it every hour of his day..

I've no access to an Xrf gun.

Does any know what alloy this gear was made from?

I may have all the parts Ian needs. This time.

But what about the NEXT guy?

Cal. Thank you for that information. I now have two cvs contacts in the uk and possibly a third thanks to you.
Thermite. Although I think I can make a suitable helical, I know it'll never be as good as the original. The tooth form will be an approximation, the finishing probably inferior and the material possibly not right. Additionally, I'd have to work out the spec details and spend a great deal of time. The whole thing would be interesting, but I'd rather buy the real deal! Repairing is a similar deal.
I've made plenty of gears and have the kit, but this lathe is otherwise right and I'd like to complete the job properly.
If, btw, I don't reply to a direct email, it's because cyberspace randomly eats inbox arrivals, so I'd need to give you a different address.
One day I'll figure out how to post a photo!

Ian

Originally Posted by ir9074

If, btw, I don't reply to a direct email, it's because cyberspace randomly eats inbox arrivals, so I'd need to give you a different address.
One day I'll figure out how to post a photo!

Ian

Email is working fine, most any address that works at all.

I just have to go offline and put on a "different hat" - or pair of Cochran double-soleds - for rest of today. Asses need kicked. Virtually at the very least.

I have indeed a manual for parts.

Somewhere, but not obvious at the moment, I have details of the tooth pitches of the headstock gears.

All I can see at the moment is that the larger gears are all 56T.

If you need a scan of any of the parts or operators manuals I can do this.

Regards.

Well, I eventually found a guy in the UK who has loads of cva lathes, some for spares. He has all sorts of stuff. Anyhow, I've now bought everything I need from him at a good price. For future information, the round dial 10ee and all versions of the cva have the same headstock and banjo gears. The later cva reverse idler sits on a shaft that is retained by a grubscrew under the headstock. My early cva has exactly the same arrangement, but the shaft is a light press fit and has no grubscrew. I assume the 10ee is the same.
Thanks to everyone for their help.
Ian

Originally Posted by ir9074

Well, I eventually found a guy in the UK who has loads of cva lathes, some for spares. He has all sorts of stuff. Anyhow, I've now bought everything I need from him at a good price. For future information, the round dial 10ee and all versions of the cva have the same headstock and banjo gears. The later cva reverse idler sits on a shaft that is retained by a grubscrew under the headstock. My early cva has exactly the same arrangement, but the shaft is a light press fit and has no grubscrew. I assume the 10ee is the same.
Thanks to everyone for their help.
Ian

For comparison purposes, going forward for next time:

The one we were about to ship, perhaps in sea-freight for weeks - would have included the shaft complete just to be on the safe side.

It is neatly drilled for an oil hole and also has a not-as-neat divot where a grub screw would be just about at sress center. Closer to the gear than free-end.

Said divot has a burr plus a bit of minor mangling. Ergo it was used, 1940/41'ish flat-belted 10EE.