Member postings for MalcB

The external jaws do not start in the scroll at the same time. The scroll is liken to a screw thread and you put the jaws in one at a time. I have no pictures so it's difficult to explain. You bring the start of the scroll round to position 1 and just as you see the start of it wind in back a little, enter jaw 1 and wind it in and round to position 2 for jaw 2 and repeat sequence. Repeat sequence for jaw 3. This should then pull all the jaws in central.

Hi John,

Congrats on your purchase.

From your first questions, don't be too quick in discarding your Perspex front swarf gaurd.. Look at the possibility of mounting on an adjustable magnetic base or similar or making it quick detachable. As mention they are very handy on brass.

From second question so: Tool profile looks OK but the cutting Geometry is not correct for the material. For alloy you need plenty of top rake on the tool and you will need to play around with tip radius for a smoother finish. I would do some research on lathe tool angles/geometry and then just have a go at grinding the tools and experimentation with different materials.

Yes, and has Roy just mentioned, reduce your tool overhang to bear minimum to clear slides, holder etc. you may actually need to shorten tools to enable this. Tool looks too long as it stands.

Edited By Malc Broadbent on 26/08/2015 08:43:46

An easy CAD system to pick up is Autosketch.

It will not however give you the industry standard .dwg and .dxf files though.

It's quite a powerful package especially for beginners and would be well suited to the posters needs if direct manufacturing files are not needed.

Vic,

I had an Air Logic Genesis in .22 single stroke that was producing around 11.5 ft/lbs. trouble was it was like using a bull worker. Don't think he ever managed to get the .177 to do 12 ft/lbs.

The .22 was consistent thru' the chrono over about 8-10 shots then it used to " throw one" in at around 10 ft/lbs or so. Did a lot of experimenting with seals and pellet combinations, plus some mechanical changes ( including barrel ) but never managed to resolve before selling on.

Quite collectable now.

I was at our Oldham shoot quite a few years ago now, when the first known field target PCP exploded. It happened whilst the owner had the Sportsmatch GC2 held between his legs whilst charging it to 200bar. Lucky to be alive and in one piece was an understatement.

Like others on here i have done much of my own special build and development, especially with my own regulators at the time. As stated, tube must be both pressure tested and ultrasonic tested for flaws. Also as stated it is dabbling in firearms manufacture if you end up over 12ft lbs ( rifles ).

Personally, I would advise leaving well alone as there are many other areas where engineering integrity can be used without infringing on firearm laws. Just saying.

Plus if these are the books on Ebay then they are about £35 i think.

Red Scotchbrite, followed by Grey then Autosol for polished finish.

I repaired many when I did an 18 mths stint in the standards room at Ferranti a long time ago.

From memory ( a long time ago ).

As stated you need a very clean, dry, score free spindle using solvents.

The only special tools other than good small screwdriver sets needed to dismantle are a couple of good sets of finger lifters. A small set for the main finger and a very small set for the revolution counter finger. These are literally miniature types of tyre levers with a small groove cut in to clear the finger spindle, 2 per set.

Depending on indicator model basic dismantle starts:

Remove Back.

Remove plastic rotating main screen either clips or screws.

Carefully lift each finger using equal pressure with lifters at 180 deg under each and lift of dial.

This usually reveals a couple of screws on the outer edge of the main gear train assembly that hold it to the indicator assembly. They allow rotational adjustment of the gear train assembly to mesh the main first contact gear with the linear spindle rack gear. Remove these screws and the gear train can be removed and further dismantling necessary of the gears and springs.

Remove the end fittings from the spindle and slide out.

Do all the cleaning and score removal necessary, check for free smooth movement in housing.

Reassembly is a reversal of above but: when you mesh the main small gear with the rack you will need to reset the preload on the main spring as follows.

Rotate the gear train so there is no mesh with spindle keeping the adjusting/locking screws lightly nipped. Very lightly refit the larger finger with the lightest tap just sufficient to rotate the gear train.

Wind about 4 complete revs to tighten the main spring and whilst then holding to prevent unwinding rotate the gear train assembly to mesh with the spindle and tighten the two rotational adjusting/securing screws. There should be minimal play twixt spindle and gear.

At this stage you need to check its operation. The spindle to be clean and smooth operation. The main finger should move promptly and cleanly and return to its zero point. You may need to play with the preload revs and meshing to get this right.

Remove finger.

Refit dial. Refit fingers by lightly tapping back down with a good small diameter flat ended punch, taking care not to bend the spindles.

Reassemble front.

Reassemble back.

No doubt there are others who may be able to correct if needed.

For HSS 3 flute, the Dormer as as good as it gets but pricey. You may want to try CNCpoorboys which are cheaper with good service. As per John, slower spindle speed with relatively slow feed but not too low it burnishes the cutting edge. It's unfortunate that there isn't really such and economical way with stainless when doing larger batch quantities by hand or by conventional machining.

I looked at the bench mills and was put off either by plastic driving gears or variable drives driven by cards. I would ask myself how long are the replacement electronics going to be available and at what cost also how could you easily diagnose issues yourself. Great for a few years under warranty but after that?

I have managed a comprehensive CNC and conventional machine shop for many years and the complexity of the electronics is NOT something I wanted in a home workshop.

The VMC machines as mentioned are easy to work on and very easy to upgrade. I lifted my head with a 100mm spacer made on my 4 1/2" Boxford. I have seen articles on using 6" spacers, but I reckon the machine would not be comfortable to use at this height. The single phase motors can be easily replaced with a good 3 phase inverter run unit to give a controlled variable speed drive that is a more workable option.

You have to ask yourself what would be most desireable if setting up a home workshop where space and costs were not a major decider. For me it would be a nice Hardinge or Monarch toolroom lathe and a Bridgeport turret mill as main stay equipment. Bridgeports havnt become an industry standard for nothing.. They have long earned their reputation as a highly desirable and versatile machine. The VMC,s are just "wanna be" reduced scale models of the Bridgeport type turret mills. A bench mill wouldn't,t be in the equation.

I was lucky in getting a used 626 machine with full 3 axis readout and power feed, with a new motor fitted. At the time I was torn between the Seig X3 super and the VMC which is now only a tad dearer than the Seig. The VMC was a no brainer and I very nearly bought an ex demo 626 from Chester but the 30 day only warranty killed the deal as at the same time a used one appeared on the market which I bought.

Looking at many articles, there are many satisfied users of bench mills and quite rightly so, as they fit space limited workshops really well. There are however bench mill users that want to upgrade to turret mills.

If you have the space, the cash, then it may be prudent to remove this last scenario and launch straight in for a VMC.

Yeh I know what you mean on the ER screw collet chuck. I am using a MT3 x ER40 that I transfer from the Miller to my now Boxford with M12 drawbar. Blind hole but I get about 55mm depth in the collets.

Without wanting to do any mods to your lathe spindle nose then you will need to do some thinking away from the box.

There is always the easy option of using a driving centre but they are quite rare to find, not seen one being sold for a while now. You may want to consider making one.

I would make a soft morse taper centre for your spindle taper with a parallel portion sufficient to grub screw a collared catch plate onto ( or Welded ).

Before turning the tapers on the centre, drill and tap the morse end for a suitable drawbar and make one to suit.

A lot of work for a per chance occasion of use but it's an option.

I have a couple of combined self contained catch plates with parallel shanks that can be held in a collet, but you do need a collet set up for your lathe for to use these.

Edited By Malc Broadbent on 19/05/2015 09:16:20

Interesting stuff on the alloy and yes it did look like it was welding the way it pooled and fused the metal.

There was a guy demoing and selling very expensive alluminium welding wire.

He makes it look so easy.

I used to have a Devils job tig welding up my damaged boat props to try and repair them and thought what an easy solution.

My mate with me said he has tried it but it never worked for him. Seemed to think it was only good on one particular alloy.

What do you guys thing?

Went yesterday ( Friday ). This being my first visit to a model engineering show.

Had a shopping list of stuff to buy and was also looking for a project to run parallel with my beam engine.

I have no interest in steam locos or basic model boats with exception of model power boats which I raced for many years. However there was plenty of other models well worth seeing. I love the traction engines.

Managed to get about 60% of tooling I was looking for plus some that I wasn't in particular looking for.

So how many people buy things on the " just in case I need it basis" or is it just me and the mate I was with?

it was good to see some engines completed.

You have to go the first day for any bargains or unusual pieces that you don't see often as they were going quite quick. Managed to sort out my parallel project I think ( about 95% sure ).

Makes a pleasant change not getting tanned for high car parking charges like at the NEC.

Chester machines was a poor offering considering the great display of equipment they have at base. Fell well short of the Warco stand.

First impression was on the whole a great experience for £10 entry.

Edited By Malc Broadbent on 09/05/2015 11:35:50

British Standard Pipe Threads used for pressure tight applications should ideally be taper thread to taper thread.

You can use a parallel female to a taper male thread, but this is only usually where soft materials are in use that are known to have some give.

It is recommended that you should never use a parallel male to a taper female.

Using parallel to taper to seal means you are relying on forcing some/excessive distortion into the material of mating surfaces to gain the sealing effect or using adhesives/sealants to assist or both. It's literally like forcing a tapered bore bush onto a a parallel shaft to effect a good seal.

For high pressure applications you should go for taper to taper as the sealing area if cut correctly is far greater.

Steven Vine - if you are bench mounting then you will need to allow for a hole in the bench and clearance underneath for the knee screw to come down into. On my early 626 model the screw comes down into the cabinet quite a bit, on mines it's 6".

Edited By Malc Broadbent on 26/04/2015 09:11:08

You can gain an extra 3 or 4 inches if you make your LH table Handwheel redundant.

Also allow at least an extra 4 inches on height as you will probably end up making a spacer to lift your Z axis range.

I have a Pratt one just over 4" dia which I cadged when we were having a full refurb of our Brierly ZB32 Drill grinder.

As Adam says its grinding where they come into their own, in particular grip spreading on spiral fluted cutters.

Mine goes down to gripping a tad under 2mm in diameter and is really true considerering it's past life. Not really worth the cost for normal jobbing type operations at their new prices. Reckon mose people was just opt for good collet setup.

I use this stuff £1/can from local pound shop. Never pass it without getting at least 5 cans. Lubes and protects. Use it on loads of things.