Member postings for mahgnia

Orifice Plates?

Pressure difference across a given calibrated plate will give an accurate flow measurement.

I think Doug is saying he has South Bend gears but his gauge does not have an 18DP section to confirm the DP..

Andrew

Edited By mahgnia on 09/08/2021 10:54:44

Matt,

The likelyhood of having the half nuts on an imperial leadscrew lathe re-engage at exactly the same position on your thread when using metric conversion gears is close to zero.

Keep using the "always engaged half-nuts/reversing lathe " method.

Edited By mahgnia on 02/10/2020 03:04:59

A positive side cut angle ensures that the tool will not pull in to the work due to backlash in the crossfeed screw.

Andrew

Is the feedscrew for the Y-axis movement absolutely parallel to the slideways? This can cause binding at the end nearest the handle.

This may be adjusted by loosening the plate that attaches the feed handle/screw to the table when the table is wound fully towards the handle.

Andrew

Peter,
My X2 has been modified to use an air spring to support the head with the additional weight of a 3 phase motor. Two M8 cap screws into the cast iron rear housing/dovetail area have been sufficient for several years without any issues.

The photos below show the setup as it was before further mods recently, including moving the mill head from the lathe and attaching it to an SX1P X-Y table.

Andrew.

Edited By mahgnia on 12/05/2018 06:48:30

Edited By mahgnia on 12/05/2018 06:53:56

Edited By mahgnia on 12/05/2018 07:04:26

#1 cutter (out of 8 cutters in the involute cutter set, PA 20 degrees) is for 12-13 teeth, so the 10 tooth pinion cannot be formed accurately with an involute gear cutter. There probably is slight undercutting on the tooth form.

The 10 tooth pinion gear was most likely hobbed.

Andrew

Edited By mahgnia on 02/01/2018 10:06:42

Edited By mahgnia on 02/01/2018 10:14:57

Pete,

What's the OD of the pinion?

Should be 12mm if MOD1.

Andrew

This is how I did this on my X2:

**LINK**

It uses differential thread principle (LH v RH)

Andrew

Edited By mahgnia on 28/12/2017 00:44:06

Andrew,

Maybe some ideas here:

**LINK**

Mahgnia

Oldskool,

IIRC from my days as an apprentice, the Harrison clutch/brake lever should have a neutral position between the clutch engagement (lever to the right) and brake(lever pushed hard to the left).

If the clutch does not disengage before being pushed hard to the left, then it needs adjustment, or is seized. Otherwise this could burn out the clutch discs and/or the brake.

I remember that the clutch adjustment was not a particularly difficult procedure, but the details escape me after nearly 40 years!

Andrew.

Dave,

The 60T and the 52T are only idler gears. They can be any size that fits to allow engagement from the spindle 40T and the leadscrew 80T gear.

The drive ratio is 1:2 which clearly means the 2mm pitch leadscrew turns at half speed to the spindle, giving a 1mm pitch thread on the workpiece.

There are usually hundreds of theoretical gear combinations that will give the same pspindle to leadscrew ratio, but only a few (if any!) will physically fit normally.

Andrew

Rainbows,

20T sun gear, 30T planetary gears and 80T ring gear gives 5:1 reduction with input to sun gear and output through the planetary carrier. ( 80/20 + 1 = 5 ). 1, 2 or 4 planetary gears will be required due to tooth numbers for even planetary spacing. (20 + 80 =100, which is divisible by factors 1, 2 or 4, or 5 etc)

MOD1 gear tooth profile gives a diameter of 82mm for the ring gear teeth, and allowing some meat for the mounting and dog clutch mechanism you should be able to keep it all at less than 100mm diameter. The only problem will be the input gear is much smaller than your 25mm shaft.

Alternatively, to give a larger sun gear diameter - 25T sun gear, 25T planetary gears and 75T ring gear gives 4:1 reduction with input to sun gear and output through the planetary carrier. ( 75/25 + 1 = 4 ). 1, 2 or 4 planetary gears will be required due to tooth numbers for even planetary spacing. (25 + 75 =100, which is divisible by factors 1, 2 or 4, or 5 etc)

Andrew

Edited By mahgnia on 15/05/2016 01:44:09

Nick,

A three stage epicyclic gearbox will give you the ratio you need in a more compact (but not necessarily lighter) arrangement.

Link below to a rope winch I recently built using a 125:1 gearbox. All gears were simple straight cut spur gears, the most complex to make being the housing ring gear. This gearbox is massively over- engineered for the power transferred, so could be made much lighter if needed.

**LINK**

Andrew.

Fizzy,

Maybe time for belt drive, 3 phase and VFD.

**LINK**

Andrew.

Ian,

If it's in an image format, just use the "Image" or "Insert Image from Album" buttons on the toolbar when you create a post.

Andrew.

Danny,

These tools do work well, but they seem to give the best result with a very fine DOC, slow feed, slow RPM, and coolant/cutting fluid.

They do have a tendency to wear quickly at the cutting edge due to the heat from the chip rubbing down the face of the tool..

Andrew.

Most useful tool I've made is a QCTP for the C6. Used all the time. I've now made about twenty toolholders to suit various tools.

Next would be the boring head for the mill. Indispensable for many jobs.

Andrew

David,

Use the topslide?

How much travel do you have on the topslide?

Otherwise EGA's suggestion using a large diameter boring tool should work.

Andrew

Edited By mahgnia on 19/10/2015 04:39:30

Edited By mahgnia on 19/10/2015 04:42:16

Brian,

Where EXACTLY is this excess play you speak of?

1. The gib screws should be adjusted to eliminate play (sideways, twisting) between the cross slide and the saddle only, but allow the cross slide to freely move along the saddle dovetail.

2. the screws 232 and 220 should be tightened as per above (temporarily leave 234 loose) to fix the nut 213 firmly to the cross slide.

3. the cross slide feed screw dial should be mounted on the cross slide screw to minimise the end play between the screw and the cross slide, but there should still be some clearance (end play) there (this is OK, necessary for lubrication and free rotation of the screw)

4. the cross slide feed screw should rotate freely in the nut 213, but screw 234 can then be screwed down to an extent that the rotational end play in the cross slide feed screw is reduced (this is the backlash adjustment). Some end play (which shows up as rotational backlash) is still desirable here for the reasons stated in previous posts.

Items 3 and 4 above will show up as front to back slop (backlash) in the cross slide movement on the saddle, but this is not important compared to any movement left from item 1, as cutting forces should automatically take up this front to back movement. The only place where this backlash may become important is when the cross slide dial feed direction is reversed (winding the cross slide back out from the workpiece), and this should be accounted for by winding the cross slide out further and then winding back in to your setting taking out the backlash. This is normal for nearly every lathe.

Hope this is helping, and not muddying the issue.

Andrew