What are you machining?

[Rannsachair]

Modified a Myford S7 Leadscrew to suit a Mk1 Myford gearbox.

Fag packet engineering:

The M300 is handy for this:

Was not easy to cut, tried a crobalt tool that was getting a fantastic finish on freecutting steel was tearing the metal off and leaving pock marks. So ended up using carbide. Still nothing like the good finish I get with most steels. Played around with feeds and speeds and had to compromise on this.
Bore and length of M300 were handy:

Not got the Tom Senior wired up so out with the wee Centec and heath Robinson fixturing:

Did the job with a #404 cutter:

Gear keys on fine:

Shaft cut down a bit:

3/8 oilite bush fitted to gearbox casting, fits perfect, though would have prefered a better surface finish:

Job done, starting to get the hang of the M300 controls, quite a change from my wee ML7.

 

[Rannsachair]

Leadscrew refitted to my friends lathe and works well:

Gearbox was a rusty £50 bargain from same place I got my Tom Senior Rotary table.

 

[Tigman]

Nicely done !

 

[Brad93]

-0.014 for a nice shrink fit.

Plus an 18T & 22T sprocket opened up to an inch. Reamer cut a thou oversize which is a ball ache but not the end of the world. They can be set with Loctite.

They were different brand sprockets to the one with the bearing which was made by "Challenge", that cut really nicely and gave a decent finish.

Had to use the reamer as when boring even with super sharp finishing inserts the material was gummy and just tearing not actually shearing off.

A 12T fenner sprocket turned nicely to 19.045mm. There's a bit of wear in the shaft so that will shrink on nicely.

So there you go, Challenge brand or Fenner brand sprockets turn nicely.

 

[Johnnybravo]

Finish turned the spigot shaft blank after it came back from stress relieving . £120 plus vat I saw as excessive as the last one in December 2019 was £69. Same company

 

[Brad93]

Finish turned the spigot shaft blank after it came back from stress relieving . £120 plus vat I saw as excessive as the last one in December 2019 was £69. Same company

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Dear god. But then the cost of fuel and electric has doubled. Must cost a fortune running their furnaces/auto claves

 

[Johnnybravo]

Had forgotten that the shaft is too long to fit in the dividing head in the mill ,so made a jig so I can machine the splines

 

[Rannsachair]

More fag packet engineering, my son gave me a sketch of what he wanted, its for his mother in law, someone has drilled too big a hole for a tap so this will locate on the tap and fill the gap using a flat rubber washer.

Lucky I have a few lumps of stainless:

 

[Johnnybravo]

Splines done. Sent for hardening.

 

[Johnnybravo]

Dear god. But then the cost of fuel and electric has doubled. Must cost a fortune running their furnaces/auto claves

Nope. It’s greed. Company that case hardened the last one in 2019 do this one now. And the price increase? 15%…… Last time I use the company in Surrey for vacuum stress relieving, they are a bunch of thieves…..

 

[minimutly]

Splines done. Sent for hardening.

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Need more info - what application, power levels, what heat treatment etc?

 

[Johnnybravo]

Need more info - what application, power levels, what heat treatment etc?

Sdkfz 251 half track. Twin disc clutch with a small third plate as an input shaft brake. Stress relieved partway through machining. Case hardened before final grinding.

 

[tigdlo]

Exhaust flanges out of 316 stainless 75 x 6mm flat bar, I started with a rough cut octagon, square piece with the corners cut off with an angle grinder but the interupted cut was brutal. The rest I ground close to shape with a 36grit cubitron II sanding disc, my new favourite abrasive. The OD, even with some interupted cut was best made with a positive rake aluminium insert and lighter cuts, it held up better than the stainless specific insert I used for the bores. ID bored in 4 jaw, OD on a mandrel then chucked back up in the 4 jaw to finish the ID.

5 ID and OD done, 2 OD done waiting for ID finishing and then drill all the holes, ordered some 20-40-80 blocks to help with the lay out.

 

[Richiew]

It's going to be a 20 tooth 18dp gear for my Southbend lathe. I got greedy and thought I'd make a few at once.

According to the DRO I am about two thirds deep into the cut with about a millimetre to do tomorrow when I hope to finish it. That's if the cutter hasn't gone blunt.

20 tooth is an easy one to do as the dividing head is geared 40 to 1 so two full turns of the handle after every cut to advance. I can't take much of a bite with the mill so those pics represent about four full revolutions and about three hours work. Just as well it's not paid work.

 

[Seadog]

I'm not sure if it's the camera angle, but that cutter looks shot.

 

[Richiew]

I was thinking that last night when I reviewed the photo.

 

[Johnnybravo]

Bit of cnc wood action today. Being Oak , it’s not really the right wood, but seeing I don’t have any Beech or Lime, it’s worth a try…

 

[Pete.]

I'm not sure if it's the camera angle, but that cutter looks shot.

That cutter is deader than dead. If you can't re-sharpen it send it to me and I will do it for you but if you keep using it then it's going to be beyond recovery.

 

[Johnnybravo]

As suspected, Oak chips too easily. Need to find something with a closer grain…

 

[The_Yellow_Ardvark]

As suspected, Oak chips too easily. Need to find something with a closer grain…

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Up the RPM and reduce the depth of cut.
It will help.