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Member postings for Trevorh

Here is a list of all the postings Trevorh has made in our forums. Click on a thread name to jump to the thread.

Thread: 3 1/2 horizontal bandsaw worm gear failure
01/05/2019 14:25:26

Hi Martin,

If and when you fit the new crown wheel you will need to set the end float/thrust.

This positions the worm shaft in relation to the crown wheel and is done by fitting shims to the bearings in the end caps

this dictates at what point the worm engages the crown and therefor will dictate how much force is applied when the two come together - too much and it wears prematurely - not enough and it will try to ride over the top

hope this helps


Thread: Can anyone solve this problem?
27/03/2019 11:14:17

Isn't it just a right angle triangle - the right angle being the base of the V block, the hypotenuse being the centre line X extended to the edge of the V block gives you the Right angle

called a scalene right angled triangle with no equal sides

so the inclusive angle will be 35 degree at the point and 55 degrees at the vertical end


regards Trevor

Edited By Trevorh on 27/03/2019 11:16:52

Thread: Siezed Drill Chuck in a Tailstock
10/01/2019 14:46:29

Or you could try to use some very shallow wedges between the chuck and the tailstock casting driving them together

Failing that make and fit a cap /pipe that goes over the chuck and can go against the casting

then through the end of the pipe insert a threaded bar/rod and secure it in the chuck

at the other end simply fit a large washer over the end of the pipe and run a nut onto it and jack it off

all good fun

Thread: Split die cutting undersize
09/01/2019 14:22:41

then certainly start with just the mid screw in tight both the outer screws backed off

This should give you a tight thread, then half a turn out on the mid screw until it a nice thread

once you get a feel for it its quite a quick process to repeat

The only other way which is slightly cheating is to screw the die and holder onto the bolt you have and set the screws once its already on the thread then unscrew the holder and it should be very close to the correct size



regards trevor

Edited By Trevorh on 09/01/2019 14:25:49

09/01/2019 14:13:25


The whole point of a split die is so it can be adjusted to suit the thread or application, we were taught as apprentices that place the die into the holder and lightly screw in the centre screw until it touches the sides of the die, now screw in the 2 side screws until tight (not overly tight) take a sample cut and try and you will find it will be a nice fit

if your not happy then adjust to suit

you can always go in the other direction and start by having the centre screw in as tight as it will go and take a cut

then back it off until you get the fit your after

regards trevor

Thread: Vacuum pump valve material
07/09/2018 15:48:41

EPDM rubber sheet will work good upto -1000mb - we use it on some plant I work on with no noticeable problems


Thread: Roll Pin drill size
03/09/2018 09:23:14

Thanks Brian,

That's just what I was trying to find


03/09/2018 09:12:00


Is there a chart or list of some description detailing what the correct size of drill should be used vs diameter of Roll pin (split type) in order to have it a tap in/press fit

I need to fit a couple of roll pins to an aluminium casting and didn't want to cause any problems



Thread: Tailstock tapping chuck
31/08/2018 18:21:21


I have created an album showing how I overcame the problem although it was not my idea but I can’t seem to find out who on this forum did

Either way it works well for me

Regards Trevor

Edited By Trevorh on 31/08/2018 18:21:49

31/08/2018 15:40:02

Just to explain a little further, if you make a round tapping guide block that fits the die holder and extend it in length

its possible to secure it in the die holder by the 3 grub screws on the existing die holder and on the extension have a further 4 grub screws that hold /locate on the square end of the tap

I machined a set of guide blocks to suit the different diameters of the taps that all fit the 1 die holder

it makes tapping work held in the lathe very easy and I can use the lathe forward and reverse to do all of the work


31/08/2018 15:17:01

If you have the same set up for the die holder then simply make a round holder that fits the existing die holder but drill and tap it with 4 grub screws these lock onto the square end of the tap holding it in place and then just use as normal,

I will see if I can upload a photo of mine tonight for you


Thread: Joint Round Edge Needle Files
31/08/2018 15:12:26

Hi Ketan,

we use to use them in the petrochem industry in the workshops when profiling slots into inconel and titanium components

basically they allow you to slot fairley accuratley by hand when it just wasn't practical to use a mill

I still have my original set supplied as an apprentice back in the 1970's


Thread: Belt Driven Hacksaws -
23/08/2018 14:47:03

There is an easier way to align or check the pulley

simply re fit the belt and trap a piece of string under one end - it does not matter which end, now rotate so that the string is pulled across the face of both pulley's

move off and bring it back onto both adjust until it touches all 4 contact points

for example if it touches both sides of the motor's pulley and not the large pulley then move the motor

keep adjusting until the string just touches both

if you want to check the correct tension then simply down load Gates Carbon Drive - its an app that measures the frequency of the belt when "plucked"

you enter the belt details and it has a proffered frequency attached to that belt size and distance between centre's


Thread: milling qestion
13/07/2018 15:57:30

The easy way is to drill the first hole at one end of the slot making sure the table is locked in position then fit an end stop, move to the other end of the slot and repeat

now you can change over to the slot mill and just traverse between the stops

Thread: another mystery object
12/07/2018 14:56:59

Hi Duncan

Think its either a J or K type Thermocouple

the red/white cable denotes its type and temp range


Thread: Is this true..?
29/06/2018 12:01:16

Haven't heard that but a 1/2" bolt was said to be good to straight lift 5 T

Look at the length and dia of the threaded part of eye bolts for example vs weight of lift

Thread: How do I undo this screw?
22/06/2018 11:59:46

Why not contact the maker and ask for a replacement tool?

Thread: computer q
22/06/2018 11:25:01

Why not google ICY BOX they are a stand alone unit that's plug in for 2.5 or 3.5 drives

simple usb connection to any platform and it works it all out for you


Thread: Warco lathe owners - what is this feature?
04/06/2018 14:03:48

Its the oil level sight glass for the saddle gears


Thread: Plastic Ban
19/04/2018 12:22:31

I am an engineer in the flexible packaging industry and I can tell you that Bio degradable plastic has been around since the late 1970's BUT the food industry refused to pay for it as the additives to make it bio degradable affected their profit margin, as does the types of printing inks used, some required lamination to keep them off the food stuff's

Its the food industry and packaging companies in general that are at fault as the more they can wrap the more they can charge.

and remember that to recycle paper has a massive carbon foot print almost as bad as Plastic recycling power wise

There is no magic answer but what is wrong is passing the "Buck" down to the consumer to deal with it

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