Hemingway Hacksaw

Not much more to do on this, then I can get back on topic. I managed to get the clamps blacked today, this is them, covered in slide way oil.

I’m really happy with how they have turned out.

Cheers

Mark

I made a start today on the ‘rotary table sub-plate’, it’s a shame None of the table t-slots line up with 0 degrees. One of them is 4 degrees out.

I made up 3 temporary M4 t-nuts and drilled out at 4, 124 and 244 degrees, and counterbored M4. The plan is now to turn over the plate, counterbore the fixing holes, fly cut the bottom, then the holes can be opened up to 8mm for the final fixings.

Once the holes are opened up, I can bolt it down and mill out a spigot on the bottom to accept the MT2 blank arbour that will locate the table.

Cheers

Mark

A bit more done on the fixture plate and the first mistake. Somehow, I managed to get the centre of the plate misaligned with the centre of the rotary table by around .5mm. I drilled out the centre hole 6mm then set about creating a circular pocket to accept the stub of the MT2 arbour that will locate the plate. It was while milling this pocket that the misalignment showed up.

I offset the table in the x axis and rotated the table to mill out the pocket. I was questioning why the pocket was ~1mm over calculated size until I noticed the pocket wasn't concentric with the 6 mm supposedly central hole.

Not to worry, the pocket is concentric with the fixing holes, I'm going to open the central hole out to 10mm and make up some spigots for centralising parts

I also shortened the blank arbour, made absolutely certain it was central and drilled and tapped it M6 for future workholding.

The plate is a good sliding fit on the arbour.

Cheers

Mark

Still tap, tap, tapping away. 38 holes to tap M8, taper and plug. At least the square drives on the taps fit 2 different tap wrenches.

Holes spotted

All holes drilled 6.7mm. Because the mill hasn’t got a depth stop, I raised the head so that full quill extension drilled the holes 25 mm. Another job to get around to is to make a depth stop. I marked up the holes that need tapping, all of the others will be drilled then reamed 10 mm to accept dowel pins for location.

More tapping

Nearly there. I’m looking forward to using this.

Cheers

Mark

Excellent work there Mark 😊

Sean

Thanks Sean👍

Things all came to a grinding halt today. I finished tapping out all of the fixing holes, then I drilled out all of the ‘dowel holes’ to 9.7 mm and reamed out the first one to 10mm. Unfortunately, the 10mm dowel pins don’t fit.

The shank of a 10mm drill fits perfectly, but when I checked with my callipers, it is 9.95mm, the dowel pins are 10.05mm.

Now I have a 10.2mm drill, but I don’t want them being a sloppy fit, and, I’m not paying £40 for a 10.1mm reamer,so I’ve ordered a 10.1mm drill and it will ‘have to do’.

I don’t want to tear down my setup to work on anything else and have to zero it all back in, so I’m stuck to waiting for the drill to turn up.

Cheers

Mark

Edited By Mark Elen 1 on 11/11/2018 00:59:39

Hi Mark

I am following your hacksaw build with interest.

Before you open up your 10mm reamed holes, can I suggest using 10mm round bar for the pins instead of the dowel pins.

Regards

Vince

Use stainless steel round bar for the pins. I forgot to mention that in the above reply.

Vince

Make your own dowl pins Mark .

Sean

Re your drillings - I woud recommend drilling through the plate for all holes. The bottom part does not need to be the same diameter, but through holes will avoid swarf building up in blind holes.

Don't forget, reamers come in different nominal sizes, a 10mm E6 is 10mm + 0.043mm ( 10.043mm) whereas the R7 fit is 10mm - 0.034mm (9.966mm)Thus giving a hole anything between a clearance fit and a very tight swaged fit.

One often sees on older drawings - "Reamed hole", which in itself, doesn't mean much.

Ps - I am sure someone will correct me if I got the decimal point in the wrong place.
BobH

Thanks for your comments gents. I did try drilling the hole I reamed out with a 10mm end mill and it did produce a sliver of swarf, so that makes sense Speedy.

I still don’t have a lathe, so making my own pins is a no go at the moment.

I did consider making all of the holes through, but the vast majority seat on the rotary table top, so will fill with swarf in use anyway. I’ll see how it goes and may well mod it in the future if it gives me grief.

Today I decided to give it a go on the latch plate slot while I’m awaiting tools. Apart from my stupid mistake of setting up with the radius of the end on centre, then trying to cut the slot and latch (which is 1/8 off centre) it didn’t go too bad. Another lesson learnt - I should of put the centre of the intersection of the slots on the centre of the table, not offset it like I did.

It’s not quite as per the drawing, but I’m sure it will still work. If not, it’s not the end of the world to make another.

I bought a batch of offcut brass from eBay to use to protect the table.

Cheers

Mark

I’ve decided I’m not happy with the plate I made yesterday:

This is what it should look like:

When I rotated the table, I had to go to 45 degrees to get the centre of the latch to line up with the cutter. I CADded up the offsets today (it’s easier than me trying to work it out) and got the following (dimensions in mm):

I’ve ordered a new piece of 3mm plate and I’m going to have another go at it. At least I know where the error crept in.

Cheers

Mark

No progress today, as I'm still awaiting tools and materials. Progress has been made on a Lathe though, I called in to see the guys at ARC and came away with a SC4 and a load of tooling. - thanks for the coffee Ketan!

Spent the rest of the day getting it onto the stand and got started cleaning it down. More tool making coming I can see.

I've downloaded and printed out the supplement to the instruction manual that is on the internet by Robert Ackert here: **LINK**

Loads of stuff in there to get me started.

Cheers

Mark

Continued on with my Boxer twin oscillator; soldered on the end blocks after re-tinning the frame & blocks, didn't want to redo... again! seems to have taken ok, got down to cleaning it up... plenty of elbow grease coming up !...



Cleaning up process …



Seem to be taking a long time with this one, family issues taking priority tho'

George.

Edited by George. Oooops…right forum... wrong thread Maybe moderator could move?

Edited By mechman48 on 16/11/2018 16:23:43

Still not much progress on the Hacksaw, but hopefully that is about to change. I’ve now got the lathe set up and after a bit of ‘fiddling’ got it to cut.

I’ve been busy today making trying to butcher a thread onto a bit of steel. The first attempt didn’t go too well, as I set up on 29 degrees, (I was wondering about the other markings detailed in the ‘additional instructions’ I linked to earlier) now I know.

So, after making a dogs dinner of the first thread, I watched Tubal Cains video on screw cutting on YouTube and managed to thread both ends. 2 different sizes, 2 different pitches, I’m getting some practice in changing the gearing of the lead screw.

Here’s my incorrect setup...on its side.

Just a bit of cleaning up to do, then I can get on properly.

I forgot, I bought MEW at the weekend and noticed I’m famous😂. The bit about this build with no lathe is ‘fake news’😂😂

Cheers

Mark

To get my thread back ‘on topic’ I made a start tonight on the crank disc. I’m busy pondering how I’m going to hold it to machine the taper in the boss. As there is quite a lot of meat to get rid of, I thought it would be a good start to skim off the outside, then hold it on a faceplate to do all of the work on the boss side, then back into a Chuck to finish the front and rim.

My first go at grinding a HSS tool bit for Ali seems to be reasonable, it is cutting.

I’m still pondering making up a mandrel and the collet for final external turning as per the instructions.

The finished disc should be 12.7mm, at present it is nearer 19mm so loads to go at.

Cheers

Mark

Picking up on Neil's point about starting with a mill. I often use my mill for turning, using a tool held in the vice, the work in the chuck, and the Z axis moving the work past the tool. The too need to be centred on the work using the Y axis feed, whcih is then locked. X axis is the 'cut' depth.

It's fine for short work. And if, like me, your mill is CNC, it's a joy to do repetition work that way.

Longer work is difficult, of course, because you not only need the space for the work, but for the distance you will feed it downwards.

Like Neil, I have sometimes reflected that the Maker community has a slightly different set of needs and priorities as far as workshop equipment is concerned.

Marcus

The taper is for the saw drive pin?

There are alternatives. A parallel drive pin with spigott and a shallow nut on the rear. Loctited to add the ‘belt’ to the ‘braces’. Even a bolt and washer in the back side to secure it.

Hi Mark,

Oops, wrong bit. The taper holding bit to affix disc to motor/gearbox output. Does the motor have a keyway? If so a keyway is the obvious modern day option?

I’m guessing that Edgar T did it that way because it was easy to do on the lathe, with no other kit available (the ’ordinary tools’ comment on the first page of the 1964 ME write up).

If you are making the collet, no problem with the angle of the taper - any angle close to design will do as long as you make both before changing the top slide angle setting. But I reckon a keyway should be a good alternative. It is only an aluminium boss.