Member postings for Phil P

Do you know if there is model engineering club nearby, if there is then one of the members may be able to call and advise you.

Phil

If that Centec 2B advert above is genuine and not an April Fools joke, then £650 sounds to be a real bargain.

Phil

I use a black "Sharpie" pen, and rub the unwanted overspill away with a fine garryflex block.

Phil

Hi Steve

You were correct, the blank size was the problem.
I made a fresh attempt using 0.053" (1.35mm) as you suggested and it worked a treat even on a long thread.

It also gave me a chance to try out the ultra slow speed inverter setting I rigged up on my Pultra 1770, I can run a thread up to a shoulder under power and then reverse it off again, I am really pleased with the results.
I just need to set up the capstan attachment now and go into mass production, but that is another story.

Thanks for giving me the advice to carry on, I had all but given up on the roller box but it works very well.

Phil

Hi Steve

Yes I did get the test piece with each one, and it does screw in easily, I actually measured the remaining bit of plain section on it to find the blank diameter and it seemed to be 1.4 mm so that is what I tested it at.

I will have another play and see if 1.35 mm works out any better, I could not see how it would work with the rollers revolving as they are not retained on the shafts, so it has to be down to the blank diameter I suppose.

Do you use any lubricant on it when forming the thread ?

Phil

PS, Just so others know what we are on about, here is a link to one.

Thread-Rolling-Head-Die-M-1-6x0-35 202976842528

Edited By Phil P on 02/04/2021 12:19:32

Steve

I have just been experimenting with those thread rolling dies with very little success.
I have 1.2 1.4 and 1.6 sizes, I tried the 1.6 first and it just necks the raw material off and the roller box has to be dismantled to remove the broken end, mine was mild steel not silver steel though.

Do you know if the three "rollers are meant to revolve or do they just form a thread as they push forward, mine do not revolve and the friction is just too great for the material to hold up against the twisting force.

I am making longer studs rather than headed screws.

Any advice would be welcome.

Phil

That looks to be very bad practice to me, very confusing and open to mistakes.

Normally you would assign each dimension a letter, and then tabulate them in a chart on the drawing for each alternative size.

Phil

Dave

You are spot on with your comments regarding air to the pickup.

The operation of the gun relies on the fact that a vacuum is generated in the gun body and it is that vacuum which draws media up the hose and entrains it out through the nozzle.
But unless the correct ratio of air and media is travelling up the hose it will never perform correctly, most people tend to have an over rich mixture and that causes the gun to pulse, the media never gets up to full speed and the performance drops off, if the mixture is too lean it will probably be exiting the nozzle with enough velocity, but there will not be enough of it to be very effective. It is a fine balancing act to get it just right.

At the point where a Guyson pickup fits, it can be adjusted in and out of a mixer box which sets the mixture to the correct ratio, it will need re-adjusting if the media type changes significantly. glass bead performs very differently to say a steel shot or other heavy media.

The condition of the actual media being used also has a great bearing on the performance of a blast cabinet as well.

Phil

I am afraid there is no substitute for more air capacity, most blast guns will only give mediocre results if you are trying to use a small compressor that cannot keep up with it.

The comment about the Guyson 400 not being any good is a bit unfair, that gun performs extremely well if it is set up correctly and has an appropriate air supply. The design goes back many decades and despite many attempts to come up with a better design over the years, it still remains one of the core products for Guyson's. In fact many people buy a Guyson gun to upgrade other makes of blast cabinet.

Phil

I run a 1972 Honda XL250, the electrics are very marginal on that as well, the bike runs perfectly until the headlamp is on then it starts to misfire at high revs.

I never got to the bottom of it and dont understand why it should do that as the lighting and ignition coils are separate units and should not affect each other.

I tried an LED bulb in my headlamp, but the rectifier must be not giving a very clean DC output and the LED lasted a matter of minutes.

I solved the problem by never going out in the dark on mine 

I am with the others on this, run the engine and see how it performs before you change anything else.

Phil

Edited By Phil P on 28/03/2021 19:15:22

I dont know why, but when you said Vroom Vroom Vroom, I immediately thought of our vacuum cleaner

Phil

Has anyone tried Sikkens Cetol Filter 7 Plus on model engine woodwork yet.

My Morris traveller wood is finished with it and it is excellent stuff, it allows the wood to breathe without any flaking off like you get with normal varnish, it also leaves a dry surface that does not attract dust as Danish oil can be prone to.

Phil

Could you use slotted cheese head screws instead ?

EKP do them
https://www.ekpsupplies.com/5ba-x-3/4-steel-ch/hd-qty-100.html

Phil

Dont know about 5BA, but could you use M3 instead they will be pretty close and readily available.

Phil

You can buy a good quality Polyurethane belt from the guy on the "Lathes" website.

I have one on mine and it is very good.

Phil

It is not advisable use silicone sealant on your Austin 7 head gasket, that is if you ever intend to remove the head again.

Dont ask me how I know !!

I only use two types of sealants for most jobs these days, Blue Hylomar and Wellseal.

phil

The guy I bought the DRO kit from is called Colin Robinson, his company is called C B R Electronics in Nottingham.

He also sells on ebay as username "3977colin".

The kit has performed without fault since I installed it, you need to make sure and ask him for the slimline scales as they take up much less space.

Glad you like the micrometer depth stop, I do use it a lot.
You need to make sure the gib on the Z axis is not loose, if it is the head can tip over when you come down onto the micrometer as it is offset to one side, other than that it is very simple to use.

Phil

I didn't bother with a DRO on the Z axis of my Boley & Leinen jig borer, I just did the X & Y axis.

For the Z axis I did however add a conventional micrometer depth stop which serves its purpose very well.

Phil

According to the GHT book you are very close.

Included angle 40 to 45°
Side clearances 5°
Back rake 5 to 7°
Tip width 0.002"
Cut Depth 0.004"

This will produce a line approx 0.005" wide in steel, with a suggestion to cut slightly deeper in cast iron.

Phil

No Problem

I use it all day every day for work, so you get to know some of its quirks.

Phil