Bookpress 5tpi Square thread help please!

The biggest thread I have cut was 8tpi and things were moving pretty fast at that.

At 5tpi,I think I might keep the toilet paper to hand !!

.Ah well! The acme threaded rod and phosphor bronze nut work out far too expensive for this item with shipping. £90 for a 3 foot length and nut.

So will now have a go at cutting an Acme single start thread AFTER I have seen whether I can mount the arch section of the press safely on the mill and accurately enough to bore it out to take a sleeved internal thread.

I suspect that this will all be a bit above my skill level but willing to have a go.

Is it possible to get the correct tool forms in the smaller shank size for my Myford? Looking to cut 8 tpi x .750”?

Cheers, Martin

Have you thought about metric, TR22 x 5mm pitch steel nuts £10, and £30 for a metre of screw fron HPC, but there are cheaper sources.

They also do 2 start options but the nuts are pricy, not much difference in screw cost though

Hi All,

Quick update.

I have sourced a 500mm length of steel Metric ACME leadscrew in 20 x 8 with matching steel nut delivered for £30 which seems very reasonable. Comes from Moore International and arrives tomorrow.

I will then start to try and set up the arch section of the press on the mill for boring out to fit the nut.

I thought I would make an alloy stub that just fits in the existing thread and sticks up a bit to allow me to centre the arch under the spindle with a Dti.

I think the SAFE setting up of this will be tricky on my WM18 so slowly, slowly will be the game here I think as the arch is such an awkward and large lump to hold securely.

Will let you know how I get on.....Cheers, Martin

Hi All,

Here is my first attempt at setting up the arch section for boring out whenb the nut and new screw arrives.

I have made an ally plug to allow the centre to be found.

I am concerned how rigid and safe this will be, also It is not sitting quite vertical and is difficult to tap into the correct place without it becoming loose. Should I try some alloy or lead sheet between the bottom and the small parallels perhaps?

I have had to raise it up a little to allow the boring bar to clear at the bottom.

Any advice is most welcome.

Cheers, Martin

Try vee blocks under the work instead of the parallels I think I see in your photo.

Better still, clamp the work via U bolts as well.

Edited By ega on 21/06/2019 17:29:38

ega, I did try vee blocks but the ones I have are way too small sadly. Will try and find some U bolts.

Martin

Martin, while you're at it have you considered extending the vertical stanchions with spacers in order to increase the available daylight? I know a number of bookbinders who have adapted their copy presses in this way, and I'm sure you could do a better job of it than most bookbinders, and for very little extra cost.

I don't know how much daylight your copy press has got, but from the look of things about 3.5 inches. This is really very little space for bookbinding purposes. As I'm sure you know, books are placed between wooden pressing boards before inserting into a press of this kind, and the pressing boards will already account for around 1.5 inches of that 3.5 inches.

If I were doing this job, I would be happier if the legs of the arch were stayed in some way, ie fixed to the bed so that they remained upright. Just in case anything started to go wrong - it might save a big problem.

Cheers, Tim

Hi Tim, I thought about that and was going to make some large hardwood blocks recessed for the nuts that would clamp to the table but it would be way too high then to allow machining.

Cheers, Martin

Why not lay it flat and use the lathe?

Martin King 2:

Good luck with the U bolts.

I realised after suggesting this that the common type consisting of a U-shaped rod with threaded ends would be impossible to fit to the normal tee-slotted table but no doubt you spotted that, too!

The effective arrangement would be two studs with an inverted U (or yoke) on top retained by nuts.

I thought your idea of introducing some slightly compliant packing - lead, aluminium, etc - was a good one.

Not just me being thick I hope, but isn't this an extra-difficult holding problem?

I wondered about a long wooden V block giving support underneath and machining some flats on top to give the clamps a stiffer anti-turning grip. The flats could be hidden later with body filler and paint. Glad it's not my problem!

Dave

This is the method i use when holding thin and awkward
and irregular shaped pieces for machining.
This part of a hot air engine had no flat surfaces and was
a thin aluminium casting ,using an adjustable angle plate
the top surface is covered with some aluminium tape ,the part is
attached to the plate using some plastic padding ,it is essential to
put some release agent on to the casting to release the part
easily ,a single clamp through the central slot in the angle plate
provides enough clamping force to hold the part for machining
as the plastic padding in this instance forms a shoe for the
part to sit in.
Used this method many times for these sort of jobs, works
every time.

John

Hi All,

I did not feel happy with the first setup so have taken Tim Steven's advice and used the actual bottom section of the press to hold the arch section and clamped the whole lot to the table as shown.

This is a lot more stable and managed to tke a skim cut off rough surface at the top odf the arch with a face cutter. It all felt very secure.

The only problem now is that there is not enough daylight to put my axis centring gauge in the drill chuck to get the centre point. Even with the shortest ext diameter pointer it hits the top of the arch.

Cheers, Martin

If you are short of head room, two suggestions:

1 Do it the old fashioned way with a dial indicator clamped to the quill, i.e. get rid of the drill chuck.

2 I hold the spigot of the centering indicator in a collet up the quill taper to save forfeiting several inches of head room. In my case the collet is MT2 but it means the top of the centering indicator is right tight under the nose of the quill.

I guess the accuracy of the centre isn't crucial to a few thou' so use a sticky pin in stead of the DTI.

HTH Simon

Dowel pin and cigarette paper may do the job for finding centre to your aluminum plug within a couple of thou. Short, cheap, and has worked for well over a hundred years.

Forgot to mention I have used car body filler to encase and secure irregular parts for light machining. Coat the casting in spray furniture wax or proper release agent spray, then make a plywood box to contain filler and part. kitchen plastic wrap can be used on the bed of the machine to keep filler off it. encase the part to halfway across it, like a casting parting line, then wax the face of the filler and fill the other side.

Edited By Jeff Dayman on 25/06/2019 12:25:56

Hi All,

Finally got the arch section bored out OK, had to turn it over for the last 5mm or so which was a bit nail biting!

Finished the leadscrew section and pinned both ends and loctited so all good there.

Gave all the castings a good going over with soft flap wheels which was a pretty filthy job, then used a phosphate coating and wax polish.

Looks a bit better now!

My thanks to everyone for all the help and advice, much appreciated.

Must be my week for presses, just got a much bigger one with column extensions but no normal length bolts so will have to make a couple.

Cheers, Martin

That looks like a nice, satisfying outcome Martin, well done. A world away from how it was when you bought it

Brian

Edited By Brian Wood on 27/06/2019 18:55:50

Nice job in the end and nice to see the results as so many don't let us see what happened.

David