Home made shaper for cutting gear teeth on an indexable lathe

[DAPPH]

Can anyone help or advise please ?

Has anyone used or built a simple home made shaper powered or hand driven to gouge out teeth in ally , brass or steel , as I'm looking for ideas to make my own thread indictor counter gearwheel on my lathe using the 360 degree indexed head stock gear wheel as the divider to give me 16 teeth on a 3/4 inch O/D turned up blank .
I don't have a tool post grinder and in any case wouldn't know how to source the correct cutter profile, though at the end of the day may be able to convert an old drill press to try using one ( help on that alone would be useful ) .

I remember seeing one in about 1961 at school that looked like a simple pivoting hand lever with a tool carrier in shouldered guides , it had a roller bearing back end touching operating lever handle some return springs or elastic to recover the shaper once it had passed over the work piece .c .

I seem to remember that it was only used for brass & a base metal like cast zinc for that was the major component of the engine & flywheel .
We were building a nine inch long x 4 inch dia boiler stationary steam engine at school as part of an integrated science , physics & mathematics project where we worked out he calorific value of different fuels and the efficiency of the engine for each given fuel .

The shaper tool carrier was set in two slots in the 1/4" thick base plate which was held in a vice & the carrier was moved across the work piece with a pair of fine thread thumb wheel.

If any one can point me to such a design of scraper or put up some pictures of a sensible hand operated shaper I'd be very grateful

Dave

 

[Pete.]

http://bbs.homeshopmachinist.net/threads/61390-A-Dollar-a-Day-for-A-Year

 

[MattF]

If you're using the lathe, you could just mount the tool sideways instead of upright and advance the carriage by hand for the cutting. Slow going, but would take less time than building a dedicated item for the task.

 

[Fazerruss]

If you're using the lathe, you could just mount the tool sideways instead of upright and advance the carriage by hand for the cutting. Slow going, but would take less time than building a dedicated item for the task.

I used this method to cut a keyway in a pulley I made for my cat lift. Its a bit tedious but the results are perfect. The cutting tool was an old file ground to the correct width then clamped in the tool post.
If I was to do more of this kind of task then I would make a dedicated tool for the lathe so to limit the wear on the traverse and lathe bed.

 

[Rig Pig]

There are some simple tool post mounted slotting tools on the net, mikesworkshop.weebly.com/toolpost-slotting-tool.html looks ok.

MOD - Added clicky link

http://mikesworkshop.weebly.com/toolpost-slotting-tool.html

 

[Gritineye]

Hi Dave, yes I've made a few gears in ally & steel with a modded compound slide.

The trick is to rough the teeth out with a parting tool before using the form tool, take light cuts, tighten all carriage and slide gibs as near to sticking point as you can then lock the carriage to the bed, because the large cutting area of the form tool will cause a lot of chatter which can ruin the teeth on the last few cuts after all your hard work.

The indexing has to be ridged as well, there is too much play in the indexed bull gear on my Atlas to be accurate enough for gear cutting, so I cobbled up a better method at the rear of the spindle.

The small steel gear shown was cut in around in under half an hour, if you study the second pic you will spot the indexing error in a couple of the bottom teeth using the bull gear hole indexing method.

 

[Pete.]

Gritineye that is far and away the best use I ever saw an Atlas top-slide put to - well done!

 

[CRB]

I used this method to cut a keyway in a pulley I made for my cat lift. Its a bit tedious but the results are perfect. The cutting tool was an old file ground to the correct width then clamped in the tool post.
If I was to do more of this kind of task then I would make a dedicated tool for the lathe so to limit the wear on the traverse and lathe bed.

?How big IS your cat?

Threads like this just show how much i need to catch up in the garage. I did make a simple flycutter from a chunk of steel I got from WelderPaul months ago.

 

[Gritineye]

Gritineye that is far and away the best use I ever saw an Atlas top-slide put to - well done!

Thanks Pete, I had a spare compound assy so it seemed worth a go, it makes nice graduated dials too.

 

[Fazerruss]

?How big IS your cat?

Threads like this just show how much i need to catch up in the garage. I did make a simple flycutter from a chunk of steel I got from WelderPaul months ago.

. Meant to say car!

 

[MattF]

You should have just gone with the typo flow and stuck with the large pussy.

 

[MattF]

Gritineye that is far and away the best use I ever saw an Atlas top-slide put to - well done!

I'll second that. A straight forward and efficient approach.

 

[Gritineye]

I'll second that. A straight forward and efficient approach.

Thanks Matt, since then I've got a 10" Alba shaper so I'll be gearcutting with that....

 

[ukracer]

Thanks Pete, I had a spare compound assy so it seemed worth a go, it makes nice graduated dials too.

Could you take a bit of video showing this set up and how it operates please??

 

[MattF]

If you look at the photo's above, the gear on the rear end of the headstock spindle is acting as the index gear, (so you'd pick a gear with a tooth count either matching the number of graduations you want else having a larger number divisible by the number of graduations required), then the lever on the modified topslide is used to slide the cutting tool along the piece, (the lever assembly will have a depth stop on it somewhere). You advance the cross slide to deepen the cut if necessary. When you've cut one line, pull the locating pin holding the index gear, (the sprung pin on the upright attached to the lathe with a clamp behind the headstock), out so that you can rotate the gear to the next position, then let the pin lock back into place and use the topslide lever again to create another line. Jut keep rotating the piece and marking away.

 

[DanielW]

There are some simple tool post mounted slotting tools on the net, mikesworkshop.weebly.com/toolpost-slotting-tool.html looks ok.

MOD - Added clicky link

http://mikesworkshop.weebly.com/toolpost-slotting-tool.html

And an indexer mod for the minilathe,incidently you don't have to make the indexer, if you want to just buy a set? RDG Tools have a set for £35 inc VAT,just a matter of making the plate or adapting the rigid pin to headstock

http://mikesworkshop.weebly.com/60-position-index-wheel.html

http://www.rdgtools.co.uk/acatalog/...TABLE---DIVIDING-HEAD-4--6--1084.html#SID=273

 

[Gritineye]

Could you take a bit of video showing this set up and how it operates please??

Hi uk, MattF has got the process almost right for doing most things with this method, except I drew a indexing disc for the dial graduations. The reason for that is simply the number of cuts (200) and to get the accuracy a large dial was needed to eliminate errors as much as possible.

The disc is marked out for the length of each cut and fixed to a plug in the rear of the spindle. A number stamp holder can be made and fitted to the tool post to stamp the numbers when the graduations are finished.

This pic is of the first setup I did but I then made a more rigid pointer exactly in the spindle centerline to avoid parallax errors.

Feel free to print out and use this PDF file.

 

[DAPPH]

OUTSTANDING information GUYS , THANKS .

The bull gear on the my Sphere ( similar to the Atlas ) 10 " TF ?) of the 1943's precision screw cutting lathe is almost a foot in diameter at the indexing holes , there is almost no play when the indexing pin is in .. though I haven't check every single hole to prove it . I might also be able to lock the back gears every time for 16 teeth makes for 22 & 1/2 degrees .
There is precious little for me to bolt or clamp anything to as the headstock saddle ( ? if that what the casting is called ) is of a tapering thickness of cast iron , the cross shaft gear box cover is Bakelite so NFC of bolting owt to that ..& there is no way am I going to use the headstock bearing cap clamp bolts as an anchor point for anything other than securing the headstock bearing caps .

Rigpig thanks for the link , even me with my doddery skills ad being half blind should be able to run up a simple parallel slide like the one in the link and use anyone of several different thickness parting blades ground to profile to gouge the teeth . I was envisaging having to grind a 1/4 or 1/2 inch tool tip in a tip holder to cut the teeth ,, been having lots of wake up moments thinking how the hell will I do it .

Gritineye ,
I'm chuffed to see your Atlas with grease nipples on it for my head stock shaft has taper rolling bearings that have the old one turn a week grease caps on the bearing caps on , yet the Atlas lathe manual that came out of the packing crate with the lathe in FEB 1946 says " Use thick oil every day ) . When I freed off the split gears on the headstock shaft ( absolutely solid ) I also washed the taper roller bearings out , plenty of light grey semi liquid crud ran out of them , so I took a chance and repacked them with quality high speed axle grease ,it's almost whispering now. Think I'll change those pots and the oil pots on the engage drive shaft to hexagonal brass grease nipples if can get them in the same threads ( I haven't taken one out to see if it is a Briggs grease nipple thread ) .

What size are those link belts please ? Someone has fitted solid rubber & cord fan type belts on both the motor and the gear drive wheels I'd like to use the stuff that it is designed for , though I haven't a clue as to how to describe for ordering ,the size or profile of the link belts at the minute.
This makes the motor sit too far back on its mount , unbalancing the lathe in general so any vibrations are amplified that much more even though the cast iron stand is bolted to the floor . It also means that I have to push the engage drive lever back and secure it with a bungee cord to get a good drive .... it flicks back out of drive if I don't do this)

 

[Rig Pig]

The drive system was designed for v belts however the link belting is a lot more convenient. I use Fenner power twist A section (13mm at the widest point of the belt, measure and check your set up)for my spindle drive, it give a nice smooth positive drive, don't scrimp on the belts the cheap ones are rubbish. You will need to buy a meter of belting as that's the minimum length the sell ( where I get my bits from anyway )I think you will find that the spindle bearings should be oil lubricated to ensure that they remain lubricated when operating at high RPM, grease tends to channel.

 

[Gritineye]

Always hanker after a Sphere myself, quite a few improvements over an Atlas and I love the Bakelite bits too. My QCGB is an Acorn, again better than the Atlas type.

The link belts look like the solution but aren't as grippy as an automotive belt and slippage can wear the Mazak pulley groves, I think mine are wearing. The type I have is too tall, not making speed changes easy, so unless you have to it may be best to keep what you've got but the right size, any Motor Factors should be able to supply them.
Atlas lathes came with plain v belts when new, I'm going to change back to them but it means removing the spindle.

I only have grease nipples on the countershaft. The headstock (spindle) bearings should have oil cups like mine and be oiled, my understanding is that oil washes particles out and runs cooler at high speeds, having said that I know of a few who use grease no problems, grease wasn't so good back then.

Just in case anyone wondered, the dial I was making is my design of a large direct reading type for the cross slide, loosen centre knob to zero, double the divisions of the stock one, advance .001, to turn off .001 and so much easier to see..also fitted roller thrust bearings to the shaft, smooth as silk.