Tool and Cutter Grinder

[GerryB]

G.Day Each.
On with the Work Head Assy.
Rocking Arm G11.
Looks daunting but if you scribe it out on a piece of suitable 1/2" Mild Steel(10mm should be no problem)
I find the best surface to mark on is a ground surface that has been coated with a solution of 'Copper Sulphate'
You remember the Blue Crystals in your Chemistry Set.
The Copper plating that coats the Steel will show up Scribe lines well and will not wash off during machining as Marking Blue does due to the modern solution of Suds Oil.
Note that there is a 3/16'' dia hole 3/4" back from the 3/8" hole for the threaded Boss G12/2.
Also notice that it is off centre by 3/32".
Now i rattled my brain to understand why 'off centre' seeing that it held the marker for the graduated height adjusting unit G12/1.
Then it came to me,The dia.of the pin that is used for the marker when setting the height is 3/16''.
Half of 3/16" is 3/32",the amount that the pin is off set so that the edge of the pin is the setting mark,very crafty.
The details that are fitted are quite straight forward and need no explaining,that is until you look at Drawing G10.
This is a general assembly drawing showing where the details go,such as L1/1.
But what is that at the far right?
Looks like a round piece of material held under the end by a screw piece.
Look for detail,nothing.
Can only surmise that it is a form of Weight that can be fitted when required.(see general set up pictures in the Coloured information)
It will not be too great a problem to size and make a suitable Weight and securing screw.
GerryB

[GerryB]

G.Day Pappy Frank,
I have not forgotten you,I have been finding information on the Stent.
As i mentioned at the beginning or this build,i intended to build the Stent but the freight charges for the castings alone were off putting.
Any way i found a series of articles on the Stent in back issues of the Model Engineers Workshop that may interest you.
Issue's 154,155.156 and 157.
Of course there is usually correspondence about the build in the later issues.
GerryB

[Fergus OMore]

May I venture in, please?

Actually, I have a fabricated Stent.  I bought it principally for the motor and wheels but on further examination, it worked beautifully despite being steel on steel for the sliding parts. So I dumped my on base casting etc., and stopped construction of the rest from cutting up an ancient marking out table!

Whilst I have a Quorn built from castings, there is no reason why one should not be made from fabricated parts in mild steel. The previous owner of the marking out table made one and another was made by another club member.

Yesterday, I got a 9 page copy of the Tinker drawings. Oddly, I suspect that they might have been mine originally and were passed to my club on a 'Bits ad pieces' night.

I might mention that the Brooks grinder was published in MEW 16 and 17

Hopefully, the foregoing will add a bit more information.

[Pappy Frank]

GerryB
Here is an article of a man who built a Brooks Stent without using castings.

http://www.gadgetbuilder.com/Brooks%20Grinder.html

If I decide that way, I will probably do it without castings. I have not looked at
the info you posted for me yet, but will in a few minutes.

Thanks
Pappy Frank

[Fergus OMore]

Comments removed

F O'M

[GerryB]

G.Day
 All.
I managed to acquire a suitably sized motor from a defunct clothes
dryer.
It is an Australian made unit but possibly under licence.
Anyway is looks about the size required.
Due to not being able to acquire the same model of motor as used by the
author of the Bonelle i will have to modify the motor mountings to suit.
It stands to reason that many of you are not likely to get your hands on
 the same type of motor in the Drawings so you will also have to modify
to suit.
The motor i have is supplied with Vibration Mounts.see picture.
I decided to use them as fitted so had to make a couple of mounts to
suit.
The motor mounts have a shape that keeps the motor secure,namely a
sunken central area  (for want of a better description) on the
circumference of the metal band around the anti vibration mount.
This being measured for diameter and bored out on two suitably cut
pieces of .4" thick mild steel bolted together.See photo.
The relief was then cut out by 1mm which gave me the required raised
central ares that should fit the anti vibration mount,fingers crossed.
I then cut the metal plates to allow two securing bolts to be placed at
each end like as used on a Plumbers Block.
The plates were then cut half way across the hole and cleaned up.
Now comes the test.
Offer the two halves up to their position on the anti vibration mount
and bingo they fit.
Now i have to make a suitable Motor Mounting Plate to secure to the
Wheelhead Block.
I will probably secure the motor mounts with countersunk screws.
GerryB
 

[Fergus OMore]

Hi Gerry,
            I didn't get the photos but I will not be alone in challenging your choice of motor.  I suspect that this motor will- if unchecked, rev and rev way beyond the point where abrasive wheels become unsafe.

What you should be looking for is a 2880 rpm motor of a mere 1/6th HP but I got away with a 1/4 HP one which only gave out 1440 rpm. The speed change is done with a change of pulley size. However, you should also be gearing up to perhaps double the 2880 revs for smaller wheels and follow Chaddock if you intend to use 'points' to do dies and internal boring.

Again, the motor should be capable of being reversed. OK, one of mine- on the Kennet- will not but really you are following the Quorn.

Keep us posted, please

[GerryB]

This will be the third attempt to download the photo's
GerryB

[GerryB]

G.Day Fergus,
Don't know what happened with the photo's but i got them down in the end.
The motor is a FSCO  6654 JVB A1.
I  realise that other than Australian readers it will mean nothing.
The speed is given as 1270 RPM.
Rated at 60 Watts and 0.75 Amp.
Mind you until i set it up working so to speak,i will not know if it will cope and that i shall have to fit a different unit
GerryB

[Fergus OMore]

Hi Gerry,
              I'm happy to note that your motor choice has a 'governed motor' I have no doubt that you will make the necessary adjustments to get the correct operating speeds.
Your next hurdle will be how to keep the grinding dust from gumming up the works. My Quorn has felt washers ' a la Brooks' and of course, you have the details.

Kind regards

[Fergus OMore]

I've been having 'Senior Moments' and may have forgotten to mention a web site which has- amongst other exciting things- the Mini-Bonelle.

Maybe you and others will be interested so here goes

http://www.metallmodellbau.de

And there is a funny English translation

again there is lot of interesting references on  http://www.bedroom-workshop.com

Enjoy

[GerryB]

 
G.Day Each,
Well have you spotted my deliberate mistake,see photo 044.
You will notice that the two 3/8" dia. holes in the motor Mounting Plate do not aline with the holes in the Mounting Block.
Now do not ask me how it happened,my only excuse is that i got too complacent.
Now i had visions of having to cut out a new mounting plate but then the old grey matter logged in and it came to me that all i had to do was reverse the mounting plate and remark the security bolt holes.
This would mean that i would have two 3/8"dia. holes with nothing to go in them,who cares.
So I did the necessary and fitted the plate,see photo.048.
The next item was to fit the Motor Mounting units so that the Motor centre is aligned with the Spindle Assembly.
I know that it dose not matter if the Motor and the Spindle are not in alinement but i like to get units on the square with other units.
I am a little concerned that there is no means of adjusting the distance of the Motor to the Spindle.
I realise that the drive belt will have to be made to suit but i like the idea of adjustment.
I had to fit the Motor Mounting units using Countersunk Screws in the Mounting Block side so i also used the same screws for the other Mounting Unit.
Offer assembly up and it fits.so fit the Motor and all looks ship shape.
I now have to switch the brain to informing me as to the Dia.required for the Belt Drive on the Motor.
GerryB

[Simon0362]

Yesterday, I got a 9 page copy of the Tinker drawings. Oddly, I suspect that they might have been mine originally and were passed to my club on a 'Bits ad pieces' night.

I

Just to add 2c from a lurker....I bought the drawings for a Tinker and built one by fabricating the main parts rather than shipping castings from Canada.
Happy to discuss in a PM but my overall opinion is 'not impressed'

Simon

[Fergus OMore]

Simon,
             Not wishing to 'hijack' the construction of the Bonelle again, perhaps you would open a separate post on the demerits of the Tinker.
I recall that this debate opened way back in about 1973 with a Quorn versus Tinker battle.
Regards