Thread: Face Plate Clamping

Hi,

Hare & Forbes sell T-nuts in various sizes (both metric and imperial).

Another option is to make your own T nuts, and tap them to suit the studs that you have.

Hope this helps.

Originally Posted by Sterob

Guys,
What do you use to clamp jobs to your face plates? I bought a clamping set for my mill(14mm) and another for my rotary table( 8mm, I think) and neither fit the face plate for the lathe, so I don't really want to buy another set!
Maybe I could buy some extra T-Nuts and mill them down to fit the face plate and use the 14 mm clamping set?
Are there any other ways of holding jobs to face plates? I suppose it depends on what you want to machine.

If you have a mill then T nuts and clamp plates would be a breeze .
Tnuts can be milled out of square key steel bars ,make them in one length ,drill and tap and then cut off to the length you want
From my experience for clamping onto a lathe face plate I ve never used Tnuts .
Usually grade 5 machine screws of the length required with a thick steel washer under the head , put through the face plate from the rear ,some times with a nut on the face side to hold the bolt in place while setting up.If you are clamping a large piece off centre be sure to add a counter wieght to make things even out.

Originally Posted by Sterob

Guys,
What do you use to clamp jobs to your face plates?

...and what's wrong with ordinary nuts and bolts?

They work well for me.

BTW you don't NEED high tensile steel bolts for faceplate clamping, of course you can use them.

Hi Steve,
I would be using the mill before I attached something to a faceplate and spun it around. Much safer to have the item fixed to a table. Don't forget if it is a heavy item and you don't have it on centre then balance up the faceplate by bolting on weigths on the opposite side.

Originally Posted by rodm

Hi Steve,
I would be using the mill before I attached something to a faceplate and spun it around. Much safer to have the item fixed to a table. Don't forget if it is a heavy item and you don't have it on centre then balance up the faceplate by bolting on weigths on the opposite side.

Good point Rod. I have seen some lathes "bouncing around" because of the lack of counter balance weights.

Sterob - remember if you do machine your "toughened" nuts that it will be easier to machine with a tipped cutter. Does your face plate have slots in it already, or are you putting them through the holes provided?. Can you put a picture up of the face plate as well as one of the job you want to do? - it just makes it easier for other members to see what you are exactly talking about. You could alway tap holes into the face plate which will make it easier when clamping - if the jod (and faceplate aren't too heavy you could roughly set it up off the lathe then mount it on the lathe and do the final lining up.

As suggested previously you could also make up your own studs using allthread or welding additional material onto the heads of the bolt(s) and grind them back to suit the T-slot.

All the best
MH

Thanks for the comment guys.
The item I want to machine is a triple tree( TT ) plate from a motorcycle, so I don't think it would not be that for out of balance.
I thought of using the rotary table and the mill, but I bought a 6" RT and it is a little on the small side to clamp the TT to it. (doh!) I also thought I could get a better finish while boring out the hole, on the lathe. It really needs to be as accurate as I can get.

Hi Sterob,

Is the hole you got over the centre (and I presume the one you want to bore out) does it already have a smooth round hole to clock it with - and is it in the correct position?.

Or do you only have a component drawing of the part?.

Cheers
MH

Originally Posted by Sterob

Thanks for the comment guys.
The item I want to machine is a triple tree( TT ) plate from a motorcycle, so I don't think it would not be that for out of balance.

You would be SURPRISED Espescially when you consider that this - being an alloy - would have to run at at leat a moderate speed [quote]

I thought of using the rotary table and the mill, but I bought a 6" RT and it is a little on the small side to clamp the TT to it. (doh!)

The small size could be overcome by making a jig to hold the item and attach the jig to the R/T. If it's a one off you may not want to do that.

I also thought I could get a better finish while boring out the hole, on the lathe. It really needs to be as accurate as I can get.

Yes you WILL get a better finish on the lathe, if you intended to use the RT to TURN the part as it is being bored on the mill!

If I were doing the job, I would use the mill and (potentially) the job to justify a boring head. This job would be best done on a mill with a boring head, NOT a RT to turn the item.

If you NEED to use the lathe for this job then PLEASE (at least statically) balance the faceplate and item.

You can do this by placing the faceplate complete with all items including counterweights on a mandrel and placing the mandrel mounted faceplate on knife edges - a set of old planner blades would be good - but you could even use the backs of suitably held hacksaw blades.

The knife edges have to be horizontal (of course). Check to see that the faceplate can be positioned at any point of rotation WITHOUT it rotating by its own weight.

Try this WITHOUT counterweights and see just how far OUT OF BALANCE your faceplate plus item REALLY is! Imagine this at say 300 rpm!

You can always check here for boring heads ...

http://www.hareandforbes.com.au/sample_2/home.php

...or possibly make your own boring head.

Originally Posted by Metal Head

Is the hole you got over the centre (and I presume the one you want to bore out) does it already have a smooth round hole to clock it with - and is it in the correct position?.

Or do you only have a component drawing of the part?.

The hole is roughly over the centre of the faceplate for the photo and there is a small smooth section of the hole that can be use to clock the part with.
I don't have a drawing. That bore is the only one that needs enlarging.
I actually have a boring head, but the last hole( the first one I did) I used it on took ages to do, was fiddly and I thought using the newly acquired lathe, might be a better option. Maybe I have something to learn regarding the use of boring heads?
I am beginning to think the lathe may not be a good choice for this job.

I would probably do it in the mill as well. If you can attach it to your rotary table you would have quite a quick way to find the exact centre for the boring head.

Less fiddly then on the lathe.

Jason

Hi Steve,
The boring bar was probalby below centre which means you are dragging the heel therfore limiting the depth of cut. See drawing below. I pinched that from here and this is a site well worth visiting if you need to check up on anything to do with metal machining.
If you don't have much to remove then perhaps a reamer is the way to go.

Thanks for that Rod.That might have been the problem.
The hole needs to be enlarged a few mm( not sure of the size atm) so reaming is not possible. I think I just need to practise with the boring head.

Originally Posted by Sterob

Thanks for the comment guys.
The item I want to machine is a triple tree( TT ) plate from a motorcycle, so I don't think it would not be that for out of balance. I thought of using the rotary table and the mill, but I bought a 6" RT and it is a little on the small side to clamp the TT to it. (doh!) I also thought I could get a better finish while boring out the hole, on the lathe. It really needs to be as accurate as I can get.

Hi Again,

I don't know what a TT plate is but going on the look of it you will have to machine it correctly or you could stuff up the others parts connected to it. Personally I would get a component drawing (via a manual, thte company etc). It might be pot luck to trust the hole you are going to clock up as being in situ with the existing holes. Not only time wasted but the cost and inconvenience of having to get another.

In regard to gettring the hole accurate there are other ways of checking and getting the correct diameter. If it is a nominal size you can bore it out to leave a few thou's on which can be taken out with the correct sized reamer. If you do not feel confident in reading your equipment to find out what diameter it is you could always make a spigot on the lathe and turn 3 different diameters for instance. Make one just under the size you require - then one on size - and one slightly larger (a sort of gauge).

Remember - which ever way you clock it up that the flat face must be square to the hole you bore or you will run into serious problems.

In regard to which machine you use - either way should be OK but I would favour the lathe as there are more speeds and feeds to choose from. Also there will be less chatter and more traverse than on the quill of the mill.

All the best MH

Hi Steve,

It may also be worth thinking about mounting the item on a jig using the holes as locations then mount that on the face plate or RT.

Regards
MT