Mini Lathe belt slipping

[Richard Hed]

The photo shows two belts. Which one is slipping? When you got the lathe, did YOU install the belts or did they come pre-installed?

 

[SmithDoor]

The photo shows two belts. Which one is slipping? When you got the lathe, did YOU install the belts or did they come pre-installed?

It spindle belt slips on center pulley on low speed.

Dave

 

[Richard Hed]

Are ;you sure that belt is installed the right side out? Looks to me like it is not but I cannot tell by the photo

 

[SmithDoor]

Are ;you sure that belt is installed the right side out? Looks to me like it is not but I cannot tell by the photo

The is on the pulley with little v in the groves.

The only time before this was Chinese made drill press. If tighten belt to a musician instrument it did not slip.

Dave

 

[bluejets]

Fit a decent quality belt...looks like the belt came from mainland China with the rest of it.

or...back off on the cuts (which amount you do not say)...it's a mini lathe afterall.

 

[SmithDoor]

Try ap it said 0.7 lfb.
This is a simple way

Dave

Found a belt tension guide...
https://simplybearings.co.uk/shop/files/chal_belt_tensioner_p168-169.pdfBut I don't think this covers Polly-Vee belts.
For tensioning Poly-Vee belts, it is relatively easy to measure tension by a calculation from the frequency of the note generated from the belt in tension. Load this App to your phone.
https://www.hutchinsontransmission.com/resource-center/apps/easy-tensionMeasure the centre to centre distance of the span, pulley diameters "mid-depth" of the grooves.
Or measure the belt-span from pulley to pulley at the tangential contact points.
With the data I think the app will give you a frequency of the note you should have when you Twang the belt. - Tap it with a spanner. It is "what we did" on the car production line I.E. tap the belt while using the frequency meter, then tension the belt until the correct frequency. Rotate for a full belt rotation, re-check/adjust. Doing 200 cars a shift, the lads knew exactly what tension to apply so when rotated it was correct.... But doing 1 belt you need the rotation and re-adjust, until it is correct. That was back in 1986~92...
But maybe the App is easier?
K2

 

[SmithDoor]

Fit a decent quality belt...looks like the belt came from mainland China with the rest of it.

or...back off on the cuts (which amount you do not say)...it's a mini lathe afterall.

Ok
I have look history of mini lathes they start with ¼hp using belts for speed reduction. Witch size of problem is about right.
Now today see on some 1 ½hp a little over kill if was at 50 rpm. It would twist the bedway.

So what type cut can make with mini lathe ? .

Dave

 

[minh-thanh]

I haven't used that lathe yet, but I have used another machine with a similar belt before. There is a reasonable way to prevent it from slipping: find the cutting speed and how much material should be cut. I think, with small machines, it needs cutting tools that are as sharp as possible

 

[SmithDoor]

I haven't used that lathe yet, but I have used another machine with a similar belt before. There is a reasonable way to prevent it from slipping: find the cutting speed and how much material should be cut. I think, with small machines, it needs cutting tools that are as sharp as possible

This my first time with mini lathes.
Before this lathe I some lathes with up to 30 hp.
This is a big change for me.

Dave

 

[minh-thanh]

This my first time with mini lathes.
Before this lathe I some lathes with up to 30 hp.
This is a big change for me.

Dave

H Dave .
That is a big change .
With small machines, the torque is not much, so try with the diameter of the workpiece you usually use (flywheel) and process with steel workpiece then you will know more. Using a sharp tool or sharpen tools to sharpness , with small machines is my best choice .
Use it and find the right machining method for that lathe.

 

[SmithDoor]

H Dave .
That is a big change .
With small machines, the torque is not much, so try with the diameter of the workpiece you usually use (flywheel) and process with steel workpiece then you will know more. Using a sharp tool or sharpen tools to sharpness , with small machines is my best choice .
Use it and find the right machining method for that lathe.

The chuck it self is flywheel it weight was over a ton.
Sharp tool bit is must on any size lathe.
Yes it is a adjustment for size.

I can pickup the mini lathe . On large lathes the tool bits I can pickup only.

Dave

 

[Steamchick]

Hi Dave, sounds like your lathe trumped my experience! Biggest lathe I worked on was 24ft long (Total length), 4-jaw chuck was about 20in diameter... tools were 1 1/2in square... with tips. I was turning cross-head castings at 10inches OD finished size. That was in the late 1960s, for compressor replacement parts. - Possibly the V range, which was introduced in 1958, as I think the factory that had half a dozen compressors was built after '58? This Engineering article may be of interest?

I sometimes think of the sound and smell of the cut of the cast iron when machining the same on my little lathe... The gentle hiss of the cut was "music". - The machine "talking" to me. - You don't forget those things.
K2

 

[Steamchick]

Dave, you asked, "So what type cut can make with mini lathe ?" - My answer is that it really depends on how well the lathe is supported against twist - as you mention for bigger motors/higher torque - as the bed of a "Modelling" lathe is not strong enough on its own to withstand much torque. Even when the bed is well supported, the cross-slides etc, cannot withstand the torque beyond the torque your motor will stall at. So use your experience and "don't let the cutting load drop the speed", is the simplest basic rule.
On brass less than 1/2inch I am using 0.020in cuts with a careful feed, or 0.010in cuts at a faster feed rate. But usually stay within 0.010in cuts as on small model parts there is hardly any real great volume of metal to remove, and time is NOT a problem to me. And I enjoy the time cutting metal. A lot of accurate cuts is much better than 1 heavier cut that loses accuracy by distorting the lathe! - Many people (usually with heavier ex-production machines) tell me they bigger cuts easily. "Well done" to them, but I don't. I learned (as a child) on a 3 in swing lathe driven by a foot treadle, from a Singer Sewing Machine. So small cuts were the order of the day, as my 8 year old legs could not develop much Torque! My current lathe, same size as yours, is the biggest I have owned (my 6th) and fills my work-space. If I want more lathe I can use the ex-industrial lathes at my Model Engineering club. They have a Myford ML7 - no better than mine) and a large 10in swing industrial lathe with 5H.P. 3-phase motor, and something a bit between. But I have never needed them. Fine cuts and patience will make anything that will fit in the lathe. You have the experience of cutting speeds and feeds, and knowledge to know when a cut is too big. - You can hear the motor, feel the vibration/cut/feed, and see the lathe "twist", so you'll know when you are dong too much.
No hard and fast rules here though...
K2

 

[SmithDoor]

Dave, you asked, "So what type cut can make with mini lathe ?" - My answer is that it really depends on how well the lathe is supported against twist - as you mention for bigger motors/higher torque - as the bed of a "Modelling" lathe is not strong enough on its own to withstand much torque. Even when the bed is well supported, the cross-slides etc, cannot withstand the torque beyond the torque your motor will stall at. So use your experience and "don't let the cutting load drop the speed", is the simplest basic rule.
On brass less than 1/2inch I am using 0.020in cuts with a careful feed, or 0.010in cuts at a faster feed rate. But usually stay within 0.010in cuts as on small model parts there is hardly any real great volume of metal to remove, and time is NOT a problem to me. And I enjoy the time cutting metal. A lot of accurate cuts is much better than 1 heavier cut that loses accuracy by distorting the lathe! - Many people (usually with heavier ex-production machines) tell me they bigger cuts easily. "Well done" to them, but I don't. I learned (as a child) on a 3 in swing lathe driven by a foot treadle, from a Singer Sewing Machine. So small cuts were the order of the day, as my 8 year old legs could not develop much Torque! My current lathe, same size as yours, is the biggest I have owned (my 6th) and fills my work-space. If I want more lathe I can use the ex-industrial lathes at my Model Engineering club. They have a Myford ML7 - no better than mine) and a large 10in swing industrial lathe with 5H.P. 3-phase motor, and something a bit between. But I have never needed them. Fine cuts and patience will make anything that will fit in the lathe. You have the experience of cutting speeds and feeds, and knowledge to know when a cut is too big. - You can hear the motor, feel the vibration/cut/feed, and see the lathe "twist", so you'll know when you are dong too much.
No hard and fast rules here though...
K2

I could be a little greedy with my cuts.

Dave, you asked, "So what type cut can make with mini lathe ?" - My answer is that it really depends on how well the lathe is supported against twist - as you mention for bigger motors/higher torque - as the bed of a "Modelling" lathe is not strong enough on its own to withstand much torque. Even when the bed is well supported, the cross-slides etc, cannot withstand the torque beyond the torque your motor will stall at. So use your experience and "don't let the cutting load drop the speed", is the simplest basic rule.
On brass less than 1/2inch I am using 0.020in cuts with a careful feed, or 0.010in cuts at a faster feed rate. But usually stay within 0.010in cuts as on small model parts there is hardly any real great volume of metal to remove, and time is NOT a problem to me. And I enjoy the time cutting metal. A lot of accurate cuts is much better than 1 heavier cut that loses accuracy by distorting the lathe! - Many people (usually with heavier ex-production machines) tell me they bigger cuts easily. "Well done" to them, but I don't. I learned (as a child) on a 3 in swing lathe driven by a foot treadle, from a Singer Sewing Machine. So small cuts were the order of the day, as my 8 year old legs could not develop much Torque! My current lathe, same size as yours, is the biggest I have owned (my 6th) and fills my work-space. If I want more lathe I can use the ex-industrial lathes at my Model Engineering club. They have a Myford ML7 - no better than mine) and a large 10in swing industrial lathe with 5H.P. 3-phase motor, and something a bit between. But I have never needed them. Fine cuts and patience will make anything that will fit in the lathe. You have the experience of cutting speeds and feeds, and knowledge to know when a cut is too big. - You can hear the motor, feel the vibration/cut/feed, and see the lathe "twist", so you'll know when you are dong too much.
No hard and fast rules here though...
K2

I try turning O1 tool steel today make a carriage lock .
It did job did take a few more cuts.
Nice smoth cut also today I had my Aloris tool post in stall that help too. The four way is not very good.

No greed or belt will slip.

Dave

 

[SmithDoor]

The lathe is working great.
Made an install a carriage lock today.
Planning on extending the cross feed to 4".

Did find out you need a stub Morse tapper drill chuck. So now looking cutting the arbor on my drill chuck.

Dave

 

[Steamchick]

Hi Dave, what we are all looking forward to are some pictures - to inspire us to improve our lathes..?
Ta,
K2

 

[SmithDoor]

Hi Dave, what we are all looking forward to are some pictures - to inspire us to improve our lathes..?
Ta,
K2

Here is the install Aloris.
It made the lathe . Did made and install . I will take photo later. The 4 jaw back is not much to look it is 5"
Next thing is to cut the Jacob's ball bearing shank down to fit the tail stock and live center.

I got tool post and drill chuck when single and self employed.

Dave

 

[SmithDoor]

Hi Dave, what we are all looking forward to are some pictures - to inspire us to improve our lathes..?
Ta,
K2

Here good photo of turning a square shaft in a steady rest.
It is in down load section too.

Dave

 

[SmithDoor]

Hi Dave, what we are all looking forward to are some pictures - to inspire us to improve our lathes..?
Ta,
K2

More photos
Note Camara turns the bright and shiny bedways that color.

 

[Engineeringtech]

Poly V-Belts are not very expensive. If they fit the sheaves properly and the sheaves are aligned, they should grip pretty well. Even if a bit loose. It may be that they are now glazed and don't grip well. Perhaps you should go to the auto parts store and buy some belt dressing. I used it on standard V-belts for years and it helped quite a bit. Just don't overdo the amount you use.