Outrigger for AT1628VS lathe

[Robbo3]

Outrigger for AT1628VS lathe

Although you can buy an extension for the AT1628VS,it attaches in line with the bed. To be able to use it, I have to move both the lathe & a load of other equipment that's in the way.
The Stratos & Record lathes have an outrigger that is at right angles to the bed. This would be a much easier solution for me so I went about devising one.
Two things I wanted were, for it not to be a permanent fixture, thus removable & not to have to drill any holes in the lathe or legs.
The position for the extension on both the lathe bed & on the legs are threaded 3/8" UNC, with the supplied bolts being 2" long. These would protrude too far allowing the possibility (near certainty in my case) of catching myself on them.
So I bought 10 shorter ones off Ebay along with matching nuts.
I then went to a local steel stockist where I bought 2m of 50x50x3mm angle iron for £10. They cut 700mm off the length for me which was the maximm length I needed.
First cut a long notch to clear the leg. I levelled the iron & clamped it in place to mark the position of the bolt holes from the inside of the leg

A second piece of angle iron was cut for the inside. A small piece of angle iron & a flat piece were cut to act as spacers inboard & out board respectively. I'm using whatever bits I have to hand.
Luckily there is an excellent welding workshop just round the corner & he charged me £10 to weld the pieces together. Well worth it as I didn't have to find all the bits for my stick welder & twice in the past I got arc-eye.
Trial run.

Finished item, tarted up with a bit of black paint & a removable support leg.
If I were starting again I would probably use thicker angle iron because there is a little sideways wobble from the flex at the corner of the notch. I may add a strengthening plate if it becomes a problem.

 

[TopCat 32]

very interesting Robbo, i posted a little while ago, i was looking to replace my lathe and wanted 1 with a swivel head outboard turning attachment so discounted the axminster , and was looking at stratos twister and maxi 1 , would using 5mm angle get over the whip problem? , do you get any vibration through the rest, any chance of a update in a few weeks with how it is preforming<
cheers Tim

 

[Robbo3]

Outrigger update.

After the first use, the outrigger is somewhat wobbly with an out of balance piece in the lathe. Attaching an angle bracket to the right hand corner so that it pulls against the inside of the leg of the lathe, steadied the movement. It is caused by the metal being too thin as stated earlier. I may weld a thickening plate on the side to stiffen it up.
There wasn't really a problem using the outrigger, just that I couldn't get the speed over 300 RPM. With a balanced workpiece I would expect a much smoother run.

I also forgot to account for the thickness of the stepped washer under the banjo. Luckily the piece removed to create the notch was cut in half & used to thicken the bed. So using a thicker material should solve both problems.

Anyone attempting this will need to find a method of raising the rest by about 8". The extension post for the Axminster is 9" so my outrigger could do with being an inch lower.

I built this for occasional use, so it depends on the wood that I have, being too big to turn over the bed & me remembering to take photos.

 

[Chris152]

Robbo - is there a reason you didn't opt to make a floor-standing stand for the rest? Is the disadvantage of them that they get in the way as you try to move around the workpiece? Just interested, as I'm thinking about getting one (floor-standing) for mine.

 

[Robbo3]

In my case the problem is lack of storage space however I didn't look at other methods.
I also didn't want a heavy base to get out & put away every time I needed to use it.

 

[Robbo3]

Further update.

Another turner has kindly welded a piece of 25mm angle along just over half the outside of the outrigger. This has really stiffened it up & stopped the whip (sorry no photo).

 

[Simon_M]

Apologies. I should have looked at this thread before starting a new one and I’m keen to use your knowledge gained so far.

I would be tempted to buy thicker/deeper angle iron, welded into a rectangle for strength. Previously, I wanted to make an outrigger however I’m now thinking a bed extension attached to the cast iron legs would be a good solution if the space can be found e.g. a reorganisation.

I find it interesting that wood/steel share many properties, as do wood/cast iron e.g. a wooden floor support can be both rigid in compression like steel and damped like cast iron.

My interest in an extension is more out of plain curiosity. Just how many big bowls will I need? It’s more to prove it could be done e.g. useful to know. I have not lost sight of the cost of getting the OEM extension if all else fails.

Any chance of some pictures e.g. with this setup, made this bowl... ?

 

[Robbo3]

The only photo I have is the last one with a 17" (430mm) burr in the lathe. If you click/tap on it, it comes up full size which makes it clearer. The contrast is poor because of the shower curtain over the far end of the lathe & the roller blind on the right which stops the shavings being thrown all over the workshop.

The main of the forces are downwards. Had I used thicker material I may not have needed a leg but one is easily fashioned from something as simple as a roofing batten.

I purposely chose angle iron for its strength & to make access easier. With an open end the banjo can be slid onto the ways & the banjo nut tightened with a box spanner from underneath.

In my opinion the hard part is not making the outrigger but how to obtain the correct tool rest height. My tool rest shaft extension came with the bed extension. Without it the job becomes more complicated.

 

[Simon_M]

Robbo, do you have the AT1614VS extension bed, because I recognise the 9" extension post that's also supplied? Why not use both when making a front outrigger?

How realistic would it be, to obtain a short length of extra heavy duty "industrial sized" angle iron to use the mounting holes on the cast iron leg, but provide new mounting points to the front?

So the angle iron is arranged in the "vertical" plane (extremely rigid) and the only significant "construction" required, is four oversized bolt holes for four extra bolts to attach to the cast iron feet and four threaded holes at the front, for the existing bolts to attach the extension leg as an "outrigger". A wooden ground support could be added too, if required.

This would allow the extension bed/post to be reused, with the height of the threaded holes determined by the length of the extension post. Thick steel plates can be drilled/bolted together, or a section from an RSJ used as an alternative to angle iron, depending upon what's available.

 

[Robbo3]

Yes, I have the extension for the AT1628VS. I wouldn't have contemplated making the outrigger without it, because of the height required for the tool rest.

What you suggest is certainly feasible & I would possibly do it that way if I were starting again. I'm not sure how you visualise it with "four oversized bolt holes for four extra bolts to attach to the cast iron feet".

Now that you have put that thought into my head there is probably no good reason for not using the upper set of mounting holes on the bed to mount my outrigger. Doh! Just need a longer leg.

 

[Simon_M]

Robbo, the mount points on the LH side of the lathe bed are 2” lower than on the RH end. Mounting the extension bed on LH end (and going around the corner for an outrigger) increases the swing by 4”, but it doesn’t also reach the full potential.

 

[Simon_M]

Robbo, I gave this “problem” some more thought. Ideally, I also wanted to use an outrigger, but also make full use the extension post and extension bed. I’m considering:

A) Vertical bracket attached on to the leg mount points (2/4 bolts)
B) Vertical bracket attached on to the lathe bed mounts (2/4 bolts)
C) Horizontal bracket attached under the lathe and leg flange (2 bolts)

 

[Robbo3]

Tried the outrigger bolted to the end of the bed (rather than the leg). There are 2 sets of 4 mounting holes but I only use 2. Working from the top each set of holes results in the banjo being lower than the lathe bed by 2", 4", 9 1/4" & 11 1/4". So I now have 4 options.

BTW - the bolt holes are the same height at both ends. Edit: On the legs. 2" difference on the lathe bed.

I had also added a small bracket to the right inner strut to dampen the whip. This can either hook round the leg or push against it.

 

[Simon_M]

Tried the outrigger bolted to the end of the bed (rather than the leg). There are 2 sets of 4 mounting holes but I only use 2 ...

BTW - the bolt holes are the same height at both ends. ...

Using the outrigger at the end of the bed is pretty (very) nifty and the lathe bed seems more robust than the cast legs for mounting e.g. less likely to be shocked/cracked.

You only use two holes. So you can find two holes that are at the same height, and also at each end?

What I meant, by the holes are two inch lower, can be seen in your picture. The four holes for the extension are closer to the bottom of the lathe bed at the LH end compared to the RH end where they are closer to the bed. So, you couldn't slide the tailstock along and off the LH end onto the Axminster extension, like you can on the RH end (assuming you had the space) when using all four bolts? Put another way, you couldn't have two extensions (each with four bolts to the bed) and turn longer between centres (one would be lower).

 

[Robbo3]

It was you that put the idea into my head. I don't know why I didn't think of it before.

You are also correct in that the threaded holes are 1" (edit: 2" not 1") lower on the headstock end of the bed. I didn't realise that until I checked.

Would the end stop pin, which you have to take out to remove the tail stock & banjo, have a dual purpose as a locating pin?

I didn't actually use the outrigger when attached in its higher position but hopefully there should be enough length of toolrest stem to cope with the 2" drop.

You really need to ask someone who works with metal, like a blacksmith or fabricator, about the technicalities, I just bodge things as I go. However my reasoning is that the major forces are downwards & that is why I added a single leg as a brace. Thicker angle iron would probably cope without.

What I failed to comprehend was how much sideways movement (whip or sway) would be introduced by an out of balance piece. Again thicker angle iron may have cured that.

As I said before, if welding is a problem, the outrigger could be bolted together with angle brackets.

 

[Simon_M]

I didn't actually use the outrigger when attached in its higher position but hopefully there should be enough length of toolrest stem to cope with the 2" drop.

Robbo, good to see that you noticed the difference in heights! I measured the height from the top of the lathe bed to the centre of the highest pair of tapped holes - it's 1.5" on RH end and 3.5" on the LH end and hence the 2" drop e.g. 4" extra swing using the bed extension on LH end.

The end stop pin is too big to fit as an alignment pin when holding up the extension. It's also not long enough and has a thread that's not ideal, but being too big, that's irrelevant. Any piece of round bar of the correct diameter (snug but not too tight) would do.

 

[Simon_M]

about the technicalities, I just bodge things as I go. However my reasoning is that the major forces are downwards & that is why I added a single leg as a brace. Thicker angle iron would probably cope

I wouldn't say that you have bodged things. You have advanced the "science" of outriggers quite a long way!

 

[Robbo3]

Yes, you are correct. The mounting holes are 2" lower on the headstock end of the bed. Hopefully I've edited all previous entries to correct my errors. That'll teach me to dash out to a freezing shed with a torch to take a quick measurement

The purpose of posting is so that others don't make the same mistakes as I did & can post about ideas for improvements or improvements they have made.

 

[Simon_M]

Improvements or improvements they have made.

What's the "state of play" with your outrigger? Is it complete and what would you do differently if making a Mark II version? What have you used it for when overcoming existing restrictions?

 

[Robbo3]

I've only used the outrigger in anger once & that was for the 440mm burl in this thread.

As I said earlier, though it might bear repeating, I would choose thicker material to add rigidity & also give sufficient clearance for the stepped washer to be tightened without additional packing.

It works for me.