Little Adept lathe for my 5 year old

[BaronJ]

The paper has done the trick though, no movement with my finger now on the far end of the tool
View attachment 119194

Well using arm power alone to flick the chuck around, and the smallest of small cuts, I've got a finish that I think I'd be happy with, much less chatter, and a shiny finish, so tool isn't a problem. The paper has held firm too.
View attachment 119195
The 1cm of cut brass furthest from the chuck was just now, the 1cm closest to the chuck was last night before Snap, Crackle, and POP.

Good morning Jon, Norman, Guys,

I know of at least one person that has made a "Norman Tool Post" for an Adept lathe. I supplied him with my drawings, though they are sized for the Myford and would have to be scaled and sizes re calculated to suit the Adept. Certainly it would be much better than messing about shimming to get the center height correct.

This is the drawing I made based on the original patent and other information derived from Myford and RR.

 

[JCSteam]

Hi John,

Nice, so does the tool, clamp onto an increased dia toolpost? from the drawing i'm not sure how it connects for height adjustability.

Essentially its half scale id need for the adept. as the tooling i'm using is 1/4". 12mm is near as dammit 1/2".

Jon

Edit scaled to 1.5times smaller will need to measure centre height. But as I have a boat load of 20mm x 100mm mild steel kicking about in my garage, I can see quite a few toolholder been made.

 

[JCSteam]

Still not clear on how the toolpost clamped, I did some googling and came across a thread on another forum that yould commented on, and shown pics of your post. Seeing it off the post, inside the bore it all quickly became clear, and I think four of those would be a good starter set for him. R/H, L/H, round nose, and parting tool, to me are the most commonly used for plain turning operations.

Hope you don't mind me posting the pics of your toolpost, as it may be useful reference in the future to someone else.




Regards
Jon

 

[BaronJ]

Still not clear on how the toolpost clamped, I did some googling and came across a thread on another forum that yould commented on, and shown pics of your post. Seeing it off the post, inside the bore it all quickly became clear, and I think four of those would be a good starter set for him. R/H, L/H, round nose, and parting tool, to me are the most commonly used for plain turning operations.

Hope you don't mind me posting the pics of your toolpost, as it may be useful reference in the future to someone else.
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Regards
Jon

Hi Jon, Guys,

No not at all ! But I do have some suggestions. First you only need one tool block. I have two that are interchangeable, but that is only because I use one as a rear parting tool holder. So far I've not had or seen a need for more than one.

Now using your drawing ! Whilst I know that you have scaled it, there are a couple of gotchas. Looking at the bottom drawing, You show an 8 mm square cutout for the tool, but when the tool block is resting on the surface of the top slide, the top of your 6 m square tool needs to be just below center height. So the thickness of material below the tool is whatever is needed to achieve this.

You say you have plenty of 20 mm thick material, I wouldn't bother trying to meet the 16.5 mm that you have scaled it to. 20 mm will be just fine. Remember that you have a height adjusting screw to go through it as well.

Next the tool block needs to stay within the area of the base on the side where the tool is mounted. I doesn't matter if the back edge overhangs. The tool location should'nt overhang. M4 cap screws are fine for 6 mm square tools.

The post wants to be as large as you can make it, but allow 6 mm between the back of the tool slot and the diameter of the post. This will set the post diameter. The post also needs to be square and flat on the bottom. It must not rock, when fastened down it must be solid and not able to twist.

Now onto the split clamp ! The diameter of the split clamp pin has a bolt through it, so the hole for the split clamp pin needs to be far enough away from the post so that the diameter of the post doesn't intrude and catch the bolt through it. So again I would stick with 12 or even 14 mm diameter. I bored the post hole in mine using the lathe four jaw chuck and secured the pin with a screw at each end.

The post hole and the split clamp are machined at the same time.

Right this motor ! Its basically a 5 inch cube with a 2 inch high terminal box on top. The spindle is a 65 mm center height and 10 mm diameter. The fastening slots are 3 mm wide and 15 mm deep. The foot thickness is about 4.5 mm, but it varies slightly along its length.

I think that covers the motor details !

 

[JCSteam]

Hi John,

Thanks for the pointers. I had worked out that the split clamps and holder should be bored as one item, and the scaled drawing as you suggest was just to see what size roughly it would work out as, there probably isn't very much material to the bottom of the tool if I'm honest. I've a 40mm x 200mm length of mild steel bar which should suffice for the post.
The reason for looking at more than one, was to try and simplify things for Josh, one holder out and one holder in, no adjustment ect to worry about in between. As with all of it I'm trying my best to think how to make it as easy to understand and learn on as possible. The tool holder is brilliant, as it would kinda side track the centre height issue for another year. I could just set it up for him and he change them as he needs.

The top of the compound measures 1.1/2" square, with the post exactly centred, so that's 3/4" from the edge. From top of compound to centre height is 5/16" so not a lot of material left for the 1/4" (6mm) tool.

 

[BaronJ]

Hi John,

Thanks for the pointers. I had worked out that the split clamps and holder should be bored as one item, and the scaled drawing as you suggest was just to see what size roughly it would work out as, there probably isn't very much material to the bottom of the tool if I'm honest. I've a 40mm x 200mm length of mild steel bar which should suffice for the post.
The reason for looking at more than one, was to try and simplify things for Josh, one holder out and one holder in, no adjustment ect to worry about in between. As with all of it I'm trying my best to think how to make it as easy to understand and learn on as possible. The tool holder is brilliant, as it would kinda side track the centre height issue for another year. I could just set it up for him and he change them as he needs.

The top of the compound measures 1.1/2" square, with the post exactly centred, so that's 3/4" from the edge. From top of compound to centre height is 5/16" so not a lot of material left for the 1/4" (6mm) tool.

Ooo, that not a lot to go at ! Give me chance to draw something up.

 

[JCSteam]

Ooo, that not a lot to go at ! Give me chance to draw something up.

Yes it's quite small isn't it! Especially if the tool isnt allowed to overhang. 1/16" bottom, and the post itself can't be more than 1/2"-5/8" dia.

 

[JCSteam]

One other thing I've been thinking about with reference to the shower motor is surface speeds, and pulley sizes for reduction.
The following I've found as a guide for recommended cutting speeds, (SFPM).
Mild steel 100
Tool steel 70
Cast iron 60
Aluminium 250
Brass 300+

I've found the formula for converting to RPM which is (4xSFPM)/Dia. Now using this formula, the recommended speeds vary from 480rpm for CI, upto 2400+ for brass on a 1/2" dia.
For larger dia such as 1.5",as slow as 160rpm for CI, and 800rpm for brass.

Now I'm fairly certain that 2400+ would destroy the cast iron bearings on the spindle quite easily. So what range of speed should I be aiming at for the spindle. I'm inclined to think 500-1000rpm is where I need to be for good clean cuts. Which could be achieved by using a double pulley on the motor spindle to layshaft, then a reverse of the two pulleys on the spindle.

Never really looked at it before but I guess with a smaller lathe everything needs to be just right to make a good cut, including the speed that the tool is travelling across the surface of the work.
Regards
Jon

 

[BaronJ]

Yes it's quite small isn't it! Especially if the tool isnt allowed to overhang. 1/16" bottom, and the post itself can't be more than 1/2"-5/8" dia.

Hi Jon,

Yes it is very small, hard to visualise !

Anyway here is a drawing

Based on the information that I have, the the post would be 14 mm, 16 mm maximum if you reduced the tool slot wall thickness by 1 mm. Which only allows for an 8 mm securing stud diameter, indicated by the green circle.

I've used 12 mm diameter for the split clamp with an M4 screw through it. There is only 1 mm clearance there, so if you increased the post size to 16 mm you would have to move the clamp pin another mm further away.

The other thing is I don't know how much material is under the tool slot, so I've just shown it centered.

 

[BaronJ]

Hi Jon,

Yes I'm inclined to agree that 1000 rpm plus could be a bit hard on the spindle, certainly good lubrication would be important.

I'm not happy about only a 1/16" under the tool, I would want at least three times that, preferably 1/4" inch. You might need to consider just how much meat is in the top slide, and whether raising the headstock a little would work. Of course you would need to raise the tailstock as well.

 

[JCSteam]

Hi Jon,

Yes I'm inclined to agree that 1000 rpm plus could be a bit hard on the spindle, certainly good lubrication would be important.

I'm not happy about only a 1/16" under the tool, I would want at least three times that, preferably 1/4" inch. You might need to consider just how much meat is in the top slide, and whether raising the headstock a little would work. Of course you would need to raise the tailstock as well.

Hi John,

Thanks for the drawing, you drew that quicker than I could in Fusion 360 lol.
The bed casting is solid one piece, no raising of headstock without major surgery.

Unfortunately there just isn't enough there in the top slide to machine that down, maybe 1/16" then you have 1/8"-3/16 of casting, so only 1/4" overall max before your into the bottom of the casting.
At least I know I'm looking at +1/16" to get on centre height. I did read an article in ME about a guy who had separated a feeler gauge set, and punched a hole in the end for them to be fed onto a key ring, using only certain gauges a full range of centre heights could be quite conveniently arranged, the side of each tool was then marked with a number with corresponded to the depth of feeler gauge stack needed. As one of my feeler gauges has been raided this will be dismantled and used as described above. Tip ex and a marker pen providing the indicative number. I'll make another clamp with a screw to the rear, meaning I can adjust the height of the rear of the clamp without packing. I'll keep the original one original.
I'll certainly pinch your, (sorry Van Norman's) idea on the toolpost for my ML4.

I really like the design. I was offered a quick change toolpost but at nearly 50mm square would drawf the little lathe.
Jon

 

[JCSteam]

Ok, i took your dimensions John, and drew it up in fusion to see what it would look like, (i forgot the screw adjuster), however i think what you say about the thinness is correct. It looks too feeble, especially as it will be only 1/16" supporting those cutting forces.
Follow the link and click play.
https://autode.sk/33d0yt4

 

[John Antliff]

I notice from your photos that you are not ensuring that the top of the tool clamp is level i.e. parallel to the ways. This is necessary for the nut to bear down onto the tool clamp with even pressure around the nut's circumference. If this is not adhered to then the nut will press down on one side and introduce a bending force on the bolt which could, and probably will, encourage the tool clamp to move when pressure on the tool tip is present. All clamps should be parallel to the clamped surface if movement is to be minimised - applies especially to milling machine setups. To make the use of the tool clamp easier remove the cast leg and replace it with an adjusting bolt and nut of a similar size or slightly smaller to the main clamping bolt. Where the leg was, drill and tap a hole perpendicular to the surface to take this adjusting bolt and a suitable spring can be added under the clamping plate to assist in the setting up. I hope this is clear, I don't have a picture at hand but could supply one if you need it.

 

[JCSteam]

That's contrary to what I've learned about clamping, whereby the clamping force is increased if there is a downward angle towards the part that is been clamp. If the tool clamp was parallel, there is a chance that it will only be clamping on the inner edge only and the tool could be spat out as it were. I do concede its a little excessive of an angle but this was what was at hand to set the tool up to prove all was good elsewhere. The *** papers worked well for grip on the tool, and the downward angle has increased the pressure on the tool, ie less surface area greater pressure exerted.

I would like to keep the existing clamp as it is, so I feel a little metal work coming on to make a new clamp with a hex bolt to the rear to adjust the rear height. Since the lathe appears too small for the quick change toolpost.

Regards
Jon

 

[BaronJ]

Hi Jon, Guys,

Thank you for your Fusion link.

I agree the 1/16" under the tool is way too thin, though I like the rotating shim idea.

Myford supplied the Norman tool post with the ML4 lathes.
Later they went back to the same clamp style that you have on the Adept. Probably a cost cutting measure.

 

[JCSteam]

The other option is to make it and see, it seems thin, but considering that the adept isn't capable of 20thou cuts on material, the pressure if sharp tools are used, exerted on the bottom of the tool holder, is reduced significantly. It rather depends on ham fisted owners who tighten the M4 bolts down with a stilson grip lol. For Josh of course this wont be much of an issue. Plus the materials to do it are sat there.

Regards
Jon

 

[Apprentice707]

Originally I had an Adept countershaft and motor for my Super Adept. I changed these for the sewing machine motor set up when I was posted to Germany during my RAF service. I left the motor and countershaft in storage in the UK, unfortunately, the warehouse burnt down in 1980, and along with many household items the Adept parts perished.

As I remember them the motor had a double-ended armature and was a fifth horsepower. The countershaft was a simple pedestal design made of cast iron. The large pulley was about 6 inches diameter and the output pulley was the same as the headstock pulley. Simple but adequate, the belt was a round leather one with a single bent staple coupling. Hope this helps you to build up a picture.

 

[JCSteam]

Hello,

Just wanted to say a thank you to John and Brian for their little gifts for the Adept, the oil bottles, and faceplate (respectively) got here safely, thank you.

Just need to sort out picking up this little motor from you in a couple weeks John.

Regards
Jon