Bothering at a Perrin jig borer

[cheb]

It looked like this in the advert:



It's been partly disassembled into biggish lumps for transporting. Biggish meaning just liftable by one person. It needs cleaning, rebuilding and adjusting.

For those who are wondering what it does, it's basically a very small milling machine.

[demographic]

So where does the Jig part of the title come in?

[chillitt]

Should have snagged the Zephyr...

[cheb]

I don't know why they are called what they are.

I already have enough rusty Fords in my life.

[kendo57]

For those who are wondering what it does, it's basically a very small milling machine.

Big compared to mine,, what is the taper size .

[cheb]

I don't know, I haven't got that deep into it yet.

[Skub]

A jig borer is just a super accurate drilling machine. We used then when I worked in aircraft jig and tool. Basically they are one of the tools which allow a jig to be accurate/precise enough.

I've never seen them used for milling myself.

[cheb]

Ah, I'd understood they could do both drilling and milling. Oh well, I've got a better drill, I'll keep looking for a mill.

It looks like this now:



First thing I did was straighten the levelling bolts. It's been tipped onto its back without them being wound in:



Next up is dismantling this enough so I can lift it onto the bench. It weighs about the same as a 900 x600 concrete paving slab, is more unwieldy, and would grieve me more if I dropped it.



More tools needed: a 12mm allen key and an extension bar longer than my arm:

[cheb]

Curious and curiouser. The pedestal is a Perrin, it's got their name on it, and I doubt it's a counterfeit. The cross table looks like Perrin from what I can see on the net. The column is home made I think, it's welded plate steel and some has been gas cut and fettles back to completely smooth. The head? Who knows which manufacturer it might be. There's lots of research time there.

Anyway, I found out why the rise and fall mechanism was not right:



There's about 10-15mm missing from one of the teeth. It's a triple start thread too. :fun: It's possible to repair it, or have a new one made. Or just make a new rise and fall mechanism. We'll see as the rest of it goes back together.

[kendo57]

You may be able to some milling on that , the headstock bearings look substantial and my
mill only has a 2MT Taper.
See what your taper is and then get hold of some ER Collets to hold the mill bits.

[cheb]

I'm pretty certain it's not a Perrin head, judging by pictures I've found on the net. Maybe that's why the chap sold it as a mill.

And I found the broken tooth:

[demographic]

A jig borer is just a super accurate drilling machine. We used then when I worked in aircraft jig and tool. Basically they are one of the tools which allow a jig to be accurate/precise enough.

I've never seen them used for milling myself.

Ahh, that makes perfect sense now. Should be either pretty good or if old and worn capable of being restored to good then.

Hmm, the kind of thing that would be handy for making caliper relocation brackets to do things like fit a Brembo four pot to a Kawasaki motocross fork leg.

I don't actually know anyone that feel the need for such a specialised item obviously but...

[cheb]

Looks like this now. All running smoothly. I need to get a 5 stepped pulley for the motor. It's a 1/4hp motor, it might be worth upgrading to a 1/2hp, we'll see.



The compound table is apart and on the bench. I'd estimate each piece weighs, on average, about 30kgs. They all need cleaning and checking, there's the odd missing bolt and screw.



The underside of the bottom section looks good, no major corrosion:



While I was doing stuff I left this on the very oiled table:



That's for giving the shredder it's occasional oiling. I don't know if it needs it, but it won't do it harm.

[cheb]

The cleaned and checked bottom section back on the base unit. I use kerosene and fine wire wool to shift the dried on oil, grease, and any light rust. It's lubricated with whatever semi synth motor oil I have about the place. Frequently it's from 5l containers scrounged from a mate's garage, tipped on end to drain overnight. It nets me enough to do the lawnmower and keeping the workshop machinery ways lubed.



There's at least two missing bolts on this. Nothing special, M6, so I'll be ratching through the big box of random bolts later.

[cheb]

Mid section on. It had to go on like this to clear the column.



On and roughly square. I still need to put the bed wipers back on, small felt pads in an aluminium housing that wipe oil over the beds and keep a lot of swarf and chippings out. One of the wiper housings has a distance indicator on it. I've also got to adjust the gib, a piece of steel that takes up the clearance between the beds and stops chatter and backlash.



Clag:

[cheb]

All back together:



A couple more minor problems, the locking bolts are bent, the longer one enough that it doesn't line up though the mounts. Either I straighten it, or I make new ones.



Now for the chuck, an uninformative picture up the way:



It takes collets. This one will do 9-10mm diameter cutters. 34mm long, 25.5mm at its widest, tapering down to 18.5mm.



It's a Perrin table.

[cheb]

A very small amount of research suggests it's an ER25 collet chuck, and they seem common. Frightfully common.

[kendo57]

That is an ER Collet, check the size against this chart, looks like ER25

https://www.ebay.co.uk/i/231297008145?c ... gIABfD_BwE

[cheb]

Thanks. It was measured using plastic calipers. I'm off to Ebay for some Chinese tat.

[cheb]

It cuts:



Very badly and with much trepidation. I found a 10mm cutter in a box of randoms I was given. Sadly even that bare scratch was too much for a pillar tightened down with couple of nuts wrung onto a 12mm headed bolt, I could see the pillar moving back and forth.

And the high tech rise and fall mechanism gets in the way: