Member postings for BOB BLACKSHAW

I have brought some 1/4" ME taps, the plug tap comes with a point, the 3/8 "has no point.

I phoned the supplier that I needed to thread blind holes with the 1/4 "plug tap, they explained the reason of the point on the end and why a lager tap has a small hole on the cutting end.

To get over the problem I can grind the point off but I still will not be able to tap to the bottom of the blind hole.

As I don't want to ruin the plug tap but with other small taps I have ground down to the start of the thread so have a flat bottom, as these old taps were from the working days they didn't cost me anything.

The ME plug tap and second tap has about 3/16" before the start of the thread.

I thought about tapping 1/4" steel and then insert the tap and just before the thread starts at the other side, grind it flat using the 1/4" steel as the stop.

Any suggestions if this is incorrect way of doing this.

Thanks Bob.

What I can remember from the early 1970s Whiskers catalogue was sheets of A4 with parts and offers.

I use to cycle there from Luton with mates from the cycling club to see what was on offer, I think that they specialized in Campagnolo, very expensive at the time but the best.

Good price for that bike Hacksaw, looks early 90s.

Bob.

Edited By BOB BLACKSHAW on 07/09/2018 02:47:49

Thanks for the replies. I shall be using brass and aluminium so it seems carbon will be okay.

Bob.

I need to get three types of ME taps and dies, I can get carbon steel which are a lot cheaper than HSS. I need to buy nine taps and three dies, I could get away with six taps, second and a plug on each.

My question is am I wasting my money on Carbon steel .

Bob

After finishing a grinding rest I ground up some tools from the L H Sparey book using the angles for the basic tools required.

Are angles that important.

I ground up a tool for brass 2 deg 5deg 5 deg, but when I tried it I thought that tools I ground with steeper angles worked better.

The knife tool at 55 deg 5 deg 5deg actually cut brass fine, I used the same speed for all tools.

Am I doing something wrong.

Bob

I've picked up a manual drill grinding jig, the Picador design.

I am at the moment what is the best side of the wheel to fit it, Picador on the instructions have the drill on the side, other designs on the front.

They may be no good but they have been going for years so worth a try

Bob.

Regarding Johns post,

The instruction manual for the VDF is quite involved for me but I will check this out, thanks.

Thanks for the replies.

As for Dave reply it first showed LU error on the 15th of July when I first noticed the problem, now no LU is shown on the inverter.

I shall have a look at all the connections and see what happens.

Bob.

I am still having problems with the inverter with a drop in the 50hz which is varying the speed of the motor.

I contacted the power network at 5.00pm and a engineer came at my house a 10.00pm. The engineer had a look at the inverter and the 50hz dropped to 49.2hz then went back to normal, so he could see the problem.

He checked my supply under load and the voltage was 244 -1, then checked the ELI which was 0.3 ohms, he was happy that the supply was not the problem and a voltage checker over two weeks was not needed.

Any other ideas what the problem could be, as the Inverter supplier is convinced that its a supply problem.

Thanks Bob

Checking up on the internet that was the DC6 that landed at Cranfield.

I was at the right place at the right time as it came over me at around 50ft, fantastic sight.

Bob.

I was cycling at Cranfield on Thursday morning at around 11.10 am when a old passenger aircraft came over me as it was about to land.

The aircraft in my opinion must of been a early 1960s it was a propeller driven and sounded like a vintage engines.

I am surprised that a old aircraft is kept airworthy, the cost must be high.

Does anybody on the forum know, or how can I find out what aircraft this was, it was similar to a Britannia, sort of plane you would find at a museum like Duxford.

Thanks Bob

Hello all,

Its single phase, but this afternoon the Inverter been working correctly,this must of been sum sort of drop in supply,

Thanks for all of the replies.

The model engineering forum is top marks for input, I have a MGB and only get usually one or no replies with some problems I have on the MGB forum.

Perhaps try here in future.

Again Thanks, Bob.

I used my lathe today it has a Jaguar Club Inverter fitted.

When using it the power was fluctuating noted on the inverter and sound of the motor.

LU came up on the inverter, looking at the manual it states undervoltage protection.

Any help please.

Thanks Bob.

Edited By BOB BLACKSHAW on 15/07/2018 12:56:55

I am 5ft 5in tall and have just measured my set up and have the same measurements as Peter G Shaw, but with a 2,1/4 inch step for the lathe

The mill has the standard metal base for the machine and gives 40 inches to the bed, if I was much taller the milling set up would be uncomfortable as I would be bent over.

The mill base should be at least 3 inches higher for the average height today, but I think cost of manufacture comes into this

Bob

The lost technology series, Model Engine Construction by J Alexander, first published in 1894 with over 322 pages.

This book is a great read,amazing what the engineer of that time could make with a basic lathe and tools.

Thanks for the replies on this.

The reason for advice after reading page 63 is for holding up to 6mm round for turning. I usually have to put a piece of paper under two jaws of the three jaw chuck for the job to run true.

Bob.

Reading Basic Lathework by Stan Bray page 63, using a tailstock chuck in the lathe mandrel.

I thought that this was bad practice as when force is put on the material from the cutting tool would this be unstable in the tapper.

As most tailstock chucks have a tang then how can the the chuck be held in place as side pressure will knock the chuck out.

Am I wrong on this.

Bob,

Edited By BOB BLACKSHAW on 11/07/2018 02:27:04

I melted the edge of the job when using a brazing rod, but that did take, not the silver solder.