RECORD POWER REMOUNT JAWS

[Dave B]

Hello to all.
I am thinking of buying the larger remounting Jaws from RP to mount in the SC3 chuck but just wanted to make sure there will be enough clearance from the lathe bed without the jaws bottoming out.
I've got an Axminster midi and the distance from the centre point of the drive centre to the lathe bed is 150mm.
I've tried to get hold of RP but no response

Many thanks
Dave

 

[Robbo3]

Quote from the Record catalogue :
62377 Mega jaws - We have increased the capacity of our larger remounting jaws whilst ensuring they can still clear the bed of lathes with the popular 12" swing capacity ... etc.

 

[Dave B]

Thanks for your reply.
I was wanting to know what the outside diamitter of the jaws are when closed just to be sure they will fit on my lathe.

Many thanks
Dave

 

[CHJ]

Thanks for your reply.
I was wanting to know what the outside diamitter of the jaws are when closed just to be sure they will fit on my lathe.

Many thanks
Dave

Like Robbo I can on!y find the reference to fitting on a lathe with 150mm swing and max holding diameter.

Really need someone to confirm the diameter when Chuck is at its max opening not when it's closed, rarely will they be fully closed when in use.

 

[Dave B]

Yes that would answer my query.
Thanks

 

[Phil Pascoe]

Really need someone to confirm the diameter when Chuck is at its max opening not when it's closed, rarely will they be fully closed when in use.

Which shouldn't be difficult to work out - approx. the diameter of the jaws plus the range of movement of the carriers?

 

[CHJ]

Really need someone to confirm the diameter when Chuck is at its max opening not when it's closed, rarely will they be fully closed when in use.

Which shouldn't be difficult to work out - approx. the diameter of the jaws plus the range of movement of the carriers?

That's the problem the OP is having, can't find the overall diameter of the jaws in any of the Record literature, just the statement that they will fit over a 150mm swing.

Needs someone with a set to measure them for him.

 

[Phil Pascoe]

The diameter is what they are sold as - https://www.axminster.co.uk/axminster-b ... gLz9vD_BwE
I'm using Axi as I've got them (but larger), but iirc Record are the same. The diameter is 150mm with about a 6mm gap between the plates, so if you've say 25mm of outward carrier travel from where the plates fit you'd have a potential diameter of 200mm. I don't really see where the problem lies.
If uncertain about the size as sold, just adjust til they form a perfect circle with gaps between the plates - it'll be a round figure 150mm, 200mm, 250mm etc.

 

[Richard_C]

I've been thinking of these for a DML 305 which has a 305mm max diameter, so have dug around a bit. These are my calculation plus a bit of estimating. Your max seems to be 150 x 2, 300 diameter. As there is a gap between the bed bars, you might squeeze 305 in (not that you would, but this is a sanity check on the jaws) The SC3 jaws have c. 20mm total movement available, let's say 18 to be safe.

They are bigger than the axminster jaws, although Record do sell a smaller set as well, there is a danger of getting our radius and diameter mixed up so I have worked in diameter. If you watch the video of the 'mega remounting jaws' on the record power website, at the very end they show more of the dimensions. Max expansion 316mm. Looking at the holes in the picture they are very close to the edge, so maybe the fully expanded diameter of the backplate is 320? Or even 316, That means the contracted diameter could be 296 - 302.

It's very marginal indeed, you might get them on the lathe but be unable to adjust enough. But the website is very clear "....whilst ensuring they can still clear the bed of lathes with the popular 12” swing capacity ..."

Maybe give record power a call?

 

[CHJ]

The diameter is what they are sold as - https://www.axminster.co.uk/axminster-b ... gLz9vD_BwE
I'm using Axi as I've got them (but larger), but iirc Record are the same. The diameter is 150mm with about a 6mm gap between the plates, so if you've say 25mm of outward carrier travel from where the plates fit you'd have a potential diameter of 200mm. I don't really see where the problem lies.
If uncertain about the size as sold, just adjust til they form a perfect circle with gaps between the plates - it'll be a round figure 150mm, 200mm, 250mm etc.

Those are not the size being referred to,

The Record version being discussed holds an item 275 mm (10 3/4”) diameter bowls in contraction mode. so must be getting close to 300mm diameter overall, and may be only capable of mounting this diameter on his lathe with the small buttons fitted and not the larger rectangular buttons. What the OP was asking was does anyone know if this is closed to the usual working jaw gap or with jaws or fully open.

 

[CHJ]

I had a similar problem back in 2007, the then current largest diameter Axminster Cole jaws would not clear my lathe bed.

I opted for the smaller diameter ones available at the time and did my own adaptation to increase the range and flexibility of diameters accommodated on 100mm chucks.

__________Finishing off one of the small pots today, raised the thought
__________that someone may be interested in my solution to extending the Chuck Jaw range.

_________ ___ ___ ___ click on images for larger view
___________Eight 7/8 x 1/4" pieces of steel, 48 Holes, 32 of them tapped 6mm.

__________Not something you would want to poke a finger in, but no worse than a square or natural edge bowl.

 

[Phil Pascoe]

If the large cole jaws don't clear the bed, use smaller ones with a working clearance. I still cannot see what the problem is. When you know the swing of the lathe and the diameter of the jaws so long as you've a little space for adjustment, that's it surely? You're not going to be able to hold things as large as the jaws are capable of holding, that's all. The OP hasn't mentioned the size of the blank, just the jaws.

 

[Robbo3]

On the SC3 chuck:
Maximum diameter = 307mm.
Closed diameter = 284mm
Key fouls the jaw plates @ 293mm

 

[Dave B]

Guys, thank you very much for giving this your attention, really appreciate it.
On your advice I have given RP a call and they have said that from the centre to the outer edge of the back plate the radius is 143mm closed, this makes it an overall closed diameter of 284mm.
I have re measured distance from the drive centre to lathe bed and I get 154mm = diameter of 308mm give or take a mm.
So, taking that into account, Robo, as you have shown the dimensions on the SC3 I should have 20mm movement (safely) with a bit of wiggle room left without touching the lathe bed?

Extending the length of the key is not a problem, I can weld a piece onto it.

Have I worked this out right?

Chas, I do like the mod you have done on the smaller cole jaws you have, cleaver idea. Does it balance ok when the arms are fully extended?

Thanks again to you all.

 

[CHJ]

..
Chas, I do like the mod you have done on the smaller cole jaws you have, cleaver idea. Does it balance ok when the arms are fully extended?.

Balance no problem Dave; nothing that's noticeable.
Just need a little extra care keeping the hands clear of the flying extensions, although with larger items fitted they are no so prominent.

 

[Dave B]

After digging around for dimensions, Radius (centre to outer edge) of Mega Jaws when fully closed is 143 mm. My lathe's clearence (between spindle centre and bed) is roughly 154mm. This doesn't really leave much working adjustment like you said.

Chas, I think I'm going to copy your idea of the extension legs if you don't mind. Difficult to see from the photos but is that 3mm plating you used.

Thanks again to you all.

Dave

 

[CHJ]

Chas, I think I'm going to copy your idea of the extension legs if you don't mind. Difficult to see from the photos but is that 3mm plating you used.

The Flat Stock I used was:-

1/4" X 7/8" cut to 3" length. (approx. 6.3 x 2 2.2 x 75 mm)

You really need the 6mm thickness if you are going to rely on the finger plate threads alone for stud fixing and allow adequate depth for the countersink screw fixing to the Cole Jaws.

If you use thinner stock then you would need additional Button Fixing nuts behind the fingers and Cole jaw fixings may stand proud.

 

[Dave B]

The Flat Stock I used was:-

1/4" X 7/8" cut to 3" length. (approx. 6.3 x 2 2.2 x 75 mm)

You really need the 6mm thickness if you are going to rely on the finger plate threads alone for stud fixing and allow adequate depth for the countersink screw fixing to the Cole Jaws.

If you use thinner stock then you would need additional Button Fixing nuts behind the fingers and Cole jaw fixings may stand proud.

Thanks for the messurements and photos. I'll make some fingers the same as yours, 6mm sounds good to me. Stronger is always a better option
I will do them on the miller and see how they turn out.
Will keep you posted in due course.

Thanks again for you help.

Dave

 

[CHJ]

I will do them on the miller and see how they turn out.
Dave

Should make getting the hole centres accurate easier.