Member postings for Robert Dodds

Carl,

How closely does your 80T gear match the diameter and width of the big gear in your dreadnought photos. Assuming it is close you will require to bore out and add the slot for the drive peg if you are going to use that one but it's more important to establish the centre distance between the headstock spindle and the back gear shaft because this will determine whether you can use that 80T gear. The centre distance may indicate that you need a 11 1/2 tooth gear and that's a bit impractical!!.
The sliding back gear presents a different problem. Counting the teeth I can see, I'm guessing the large gear is about 40 T, way different to the bull gear behind the chuck. It looks as though the small gear with damaged teeth on the sliding gear assembly is an integral part of the slider, it may be a press fit in the 40T? gear, but either way not an easily replaced part.
If you are looking to use standard, off the shelf gears you may consider altering the gear configuration to the simpler sliding and rotating back shaft that is used on many small lathes.This could involve pinning the 40T to its shaft and getting the mate to the bull gear similarly pinned to the back shaft.
Again, as others have said,. you must start by getting the centre distance of the gear train and then decide on your gears from there.

Regards Bob D

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Edited By Robert Dodds on 28/04/2021 20:39:57

John,

Google
clamp on swivel vice.

There are lots to choose from but beware any profiled edge on you table as the throat of some of the G clamps is not huge and could reduce the stability of the vice in use.

Regards Bob D

Diane,

Nigel mentions Model engineering Societies. As you mention Nantwich there is the South Cheshire MES who meet at the back of the Peacock near the Nantwich bypass. They have a website with contact details on there and may be able to offer you some local advice /assistance.

Regards Bob D

Is the reprint article of Giles Parkes of any interest

Am I seeing a hand cranking lever and a couple of gears on the far edge of this machine. If it is, it suggests to me that there was a fair amount of manual effort involved in whatever it was doing.

Bob D

Martin,

Are yo sure the wobble is in the pulley and not due to the shaft that it sits on being a bit bent?
At least check the shaft for concentricity before boring out or modifying the pulley
Bob D

Michael,

A very interesting book to browse in . Thank you for bringing it to the forum.

Tim,
On the question of thread chasing, I was employed in the early sixties by a well known manufacturer of "gentlemen's toilets". Their "brass shop" produced lengths of threaded copper pipe which were assembled to cast brass Tees or Crosses to form the down pipe for said toilet, all being screwed and soldered together before either polishing or chrome plating.
The pipe threading was entirely done with hand chasers usually with a mandrel up the pipe to provide support and all to 26 TPI. Once started the multiple threads on the chaser ensured that the pitch of the thread on pipe was correct
One of my projects of the day was to introduce brass stamped Tees and Crosses with silver soldered joints replacing the screwed and soldered version.

Happy days,
Bob D

pgrbff,

Your motor mount picture clarifies the configuration quite a lot.
Have you still got the 1/2" rod? Seeing the type of motor mount you have I suspect that the bend in the rod is intentional to accommodate the curved movement of the adjusting lug as the motor and plate pivot on the hinge at the bottom.
It may well be a cheap compromise to avoid using an eye bolt and clevis that would, in an ideal world, enable the screwed rod to be held square to the face of the adjusting lug.
In service there is no way that the forces involved with tensioning the vee belts would over stress your 1/2" rod, unless of course, the threads are badly damaged to start with. With that proviso I suggest you do a trial assembly and stop worrying about high tensile rod replacements.

Regards

Bob D

pgrbff,

Do you know how this 1/2" rod got "bent"?
Your machine is unlikely to have more than 5 hp driving it and it is difficult to imagine that a motor of that size causing the damage. It would be more in keeping with an accidental collision with a fork truck or similar handling equipment
Is the rod used as a belt tensioner?
Unless you are constrained by having 1/2" tapped holes in the motor or machine frame consider substituting M12 studding with appropriate nuts for the present rod. At least you should source that in Italy.. As far as strength goes, M12 studding should have the capability to carry at least 2 tonne, more than the motor weight and any belt tensioning that is involved bu obviously , if other outside forces are involved some damage may result.
I googled Antique bandsaws and the images that came up show a great variety of makers and sizes and some with the motor floor mounted rather than on the machine. Would this configuration help with your project?
Hope this gives you some food for thought.

Bob D

Hi CT,

Looking at the instructions with the kit contents in your LINK I think you will require two more of the vertical strips if you are going to fit out to two windows. My guess is they make contact with only two of the three strips at each end.
I note one spade connector is up and on the other side is pointing down so you end up with three lengths of triple wire tape forming the circuit.

I guess you should see if Holden will supply you with two extra vertical strips to let you use your spare element strip on a second window and then wire the two assemblies in series to avoid the chances of overheating.

HTH
Bob D

Redex used to market these for checking compression through the spark plug hole. Most useful on multi cylinder engines to check for burnt valves or broken rings.

Bob D

Jim
Are you aware of the detail on Grayson (and many other) lathes on archive website
http://www.lathes.co.uk/grayson/index.html
It also points you in the direction of a book, The Amateur's Lathe, avidly read by many.

Bob D

Plasma,
I don't dispute your Blackbird story but how do you decide whats leaked away and whats burnt when you're doing Mach 2?.

Pattern makers still have separate rulers with allowances to suit the metal being cast. Chesterman Rabone offer a set of 4, one standard and three to suit Iron, steel and brass. (aluminium alloy is generally the same as brass). Trouble is there are far fewer local foundries than in our forefather's days so you don't see many of them nowadays. You got to go East to find them today.

Mike,
Not only temperature has a potential impact on machines. My head scratcher was a multi head driller that misaligned with the seasons and that arose from the building having been built with one corner on a wet clay bed that expanded in the wet winter months and induced a twist into the suspended first floor where the machine was sited and then shrank through the summer months. Pneumatic isolation mounts with just three reference points sorted it out but the machine did lean a bit in the winter!!
But the holes were in the right place.

As a lifelong cackhander I reckon the standard lathe was designed for us. Your body is naturally further away from the chuck and it's even better if the saddle wheel is to the right of the cross slide.
Best of all is when a lefty does any hand tool work, the left hand is tucked back and the right hand goes over the tailstock whereas the right hander has a left arm very near the chuck. Not discussing the pro and cons of Chuck guards at this point.

Regards Bob D

AJW,
Don't know the detail of your doors but I would be looking at the lengths of toothed rack as used to motor gates open and closed. A metre length for under £20 and a bit cut off could be used to slide in and out of mesh to either lock or release the doors.
Regards

Bob D

Alistair,

There are plenty of sources for TCMT 1603-04 but they are Tungsten Carbide not High Speed Steel. Are you sure about the HSS bit?
Google throws up hobby supplies with a range of prices. See what you think.

Bob D

Robert,
Pure guesswork, but have you got any photos that you could compare this machine to the pictures of lathes.co.uk who show details of an "Early 13" Harrison lathe" which just happens to list in the text 40" between centres so giving you the 1340 number.
worth a punt

Bob D

Swarf,

I think you've "nailed it" The top bit does look remarkably like a wood screw thread.

Regards Bob D

Trying to tidy up and checking the contents of long forgotten boxes of assorted screws I spotted half a dozen of these today.



They are in steel, either 3/16 BSF or 2 BA with a Phillips type head but what is the purpose of the L.H. threaded portion just under the head?

Regards Bob D

The fight for recognition was lost when the English spelling adopted Engineer as opposed to Ingenieur. The continentals associate it with ingenuity whilst the English more often think of blue coated mechanics and the Americans drive locomotives. C'est la vie!

Bob D