Mill Tramming Tool.

[BaronJ]

Hi Guys,

My current building project is a mill tramming tool.

As I mentioned I have done a drawing for this tool. There is nothing particular about the materials or the dimensions, however a certain amount of precision is required. In particular the squareness of the bar in relation to the spindle. Other than this I used material that I had on hand.

A length of 1 inch square black bar, which I think came from a scraped iron gate. It just happened to be 205mm (8.125") long and a short length of 15mm BMS. At least that is what I think it is. It actually was salvaged from an old printer. In any case just use what ever is convenient.

The black bar was put on parallels in the mill vice and skimmed to give me a flat reference face then turned over 180 degrees and skimmed on the other side. Using an edge finder I located the end and center line of the bar. Then found and dimpled the three holes shown with a centre drill. I then moved to the drill press and drilled the two outermost holes and reamed to 8mm.

The half inch hole in the middle was done on the lathe.

First I fitted the faceplate and checked for being true. For this I used a .0005 dial gauge on a magnetic base stood on the lathe bed. Surprisingly since this had spent the last 30 years or so in a box in a cupboard and I had to clean the horrible grease that was put on it to preserve it, off. The needle barely budged.

Anyway I put a centre into the tail stock and located the middle dimple to hold the bar against the face plate then clamped it lightly. Using a wobbler and my dial gauge made sure that I had it properly centered. Tightened the clamps and re-checked. It was at this point I realised I hadn't checked to see if the work would rotate without hitting anything. Phew ! It only just clears on my Myford. I must make a note that the faceplate is 7 inches in diameter and 8.5 inches will just touch the lathe bed.

At this point it is important to note which side of the bar touches the faceplate. This is the reference face.

The centre hole is drilled using a centre drill first then 5mm, 6mm so on up to 12mm. At this point I resorted to the boring bar and a half inch plug gauge.
Since I had already turned the 0.5" spigot on the spindle I made the hole a good push fit. Since I am going to use Locktight and cross pin the spigot it doesn't need to be an interference fit.

Back to the milling machine and a 4" x .045" slitting saw to cut the slots through the ends of the bar. The slot is 24mm deep. I then using the edge finder and a short length of 8mm silver steel rod, centered and cross drilled 3.2mm holes, tapped 4mm and counter bored for M4 x .75" cap screws.

Whilst I was turning the spindle I also drilled and reamed a 6mm hole about 15mm deep in the end. This is to hold a small pointed piece. But more about this later.

PDF Drawing attached.

View attachment Mill Tramming Tool.01.pdf

 

[Walltoddj]

Nice job that's basically what I had in tended on doing but a little longer to span the 9" table on my Bridgeport, looks good and it should be solid so it actually go to a tens indicator if needed. If you get any of the magazines they show one similar for sale by Pro Tram

 

[Sshire]

Good one. I have the Pro-tram and wouldn't be without it.
A few years ago, John Moore (Bogstandard) did a great build log on one.
For various reasons, John's pics have been removed by him, but Stew Hart did a build log of John's device

http://madmodder.net/index.php?topic=1077.0

 

[RonGinger]

I have seen this ad, but I dont get it. How does it work?

 

[BaronJ]

Good one. I have the Pro-tram and wouldn't be without it.
A few years ago, John Moore (Bogstandard) did a great build log on one.
For various reasons, John's pics have been removed by him, but Stew Hart did a build log of John's device

http://madmodder.net/index.php?topic=1077.0

Thanks for that link. I had no idea that there were other posts on making a tramming tool.

 

[BaronJ]

Hi Guys,

It seems that there are some other posts detailing the making of this tool. Some of the techniques that others have used were also used by me. I haven't had chance to take any photos of mine yet, but I will post them as soon as I can.

In the meantime you will see that I shaped the cross bar into a elongated diamond shape. Apart from its appearance the shaping was done in order to reduce the amount of material the M4 cap screws had to move in order to secure the dial gauge stems.

The way that I created the shape was to place a pin in the centre and one in the outside holes. Using the centre pin as a pivot I raised the end by placing a piece of 1/4" tool steel underneath. Using a fly cutter I made a number of passes until the cut got roughly level with the edge of the centre pin. I didn't bother trying to work out a particular angle since all I needed to do was make the ends thinner.

As an aside I also discovered that my mill vice pushed the work piece up on one side a fraction, even though I snugged it down with a leather hide mallet.

Note to self: Must get a decent mill vice !

I've got a pair of 0.01" dial gauges on order. I had thought of getting metric ones but the price is considerably higher. Another thing I found these imperial gauges have a metric stem of 8mm diameter. Which I find most odd since my Mercer has a 9/16ths" stem.

I still have some work to do before the tool is finished. There are a couple of parts still to be made. One of these is the spindle centre centre pin. No its not a spelling error.

You will note that I drilled a 6mm hole in the spindle. I intend to fit a hardened steel pin into it with one end ground to a shallow point, a bit like a centre punch. The idea is that by placing a bolt with a dimple turned in the head, placed in a T nut and nipped in the mill table, the point of the tramming tool can be located. Then by adjusting the table position the head can be precisely adjusted for tram.

At least that is the idea. I've started on a drawing for these parts though the dimensions for the T nut and bolt will depend upon your particular machine.

More later.

 

[BaronJ]

Nice job that's basically what I had in tended on doing but a little longer to span the 9" table on my Bridgeport, looks good and it should be solid so it actually go to a tens indicator if needed. If you get any of the magazines they show one similar for sale by Pro Tram

Nice picture ! But the price, ouch.

I've ordered two 1" inch travel 0.001 dial gauges with 8mm spindles for mine.

 

[BaronJ]

Hi Guys,

Just a quick update. I've taken a photo of the bits including the bit of tool steel I used for packing and the bit of 6mm rod that still needs to have a point put on one end. The two white parts are the plates that I made to hold the 1" square bar to the face plate. They are only there because the spindle kept rolling off whilst I was trying to take the picture.

The dial gauges still haven't turned up yet so I can't take and post a picture of the finished item yet.

I have decided that since its unlikely that everyone will have the same T nut size for the mill table, not to bother with the drawing. Its production is not vital. Its only purpose is to make it easier to shift the mill head to get it spot on. However if anyone wants a sketch...

 

[Walltoddj]

I've two 1" indicators but I'm thinking of using an R8-5/8-18 adaptor or maybe just a 3/4" bar. I like the idea of the shoulder on the adaptor so there is no movement of the main bar. Also I was thinking how do you tram a head with the spindle up or down, just a thought I've done it both ways with out thinking about it, but with the spindle extended it seems you would get better results because the farther away from the pivot will multiply the error reading does that sound right? It would be like a taper at 6" say .010" taper but at 12" it would be .020" so you can get a better tram.

Todd

 

[Swifty]

I see how your thinking Todd, but if you have a certain gap with the spindle up, it will be the same gap with it fully extended.

If you have the spindle extended though, it will be slightly more accurate reading the dials because of the greater distance from the pivot point.

Paul.

 

[BaronJ]

Hi Todd,
For the spindle why not use an R8 blank end arbour ? There is nothing sacrosanct about the size of the centre hole. You would have to be able to put the arbour into the lathe chuck (4Jaw) and ensure that it is true. Then turn it down to the size you want. Then after fitting the bar. Then its time to skim the bottom of the bar until it is true to the arbour.

What you say about the hight of the head is correct ! However any slight play in the quill will cause an error. Now you have to decide if that error is acceptable.

I've still to finish mine and I'm still waiting for the dial gauges to turn up...:wall:

 

[Walltoddj]

Hi Todd,
For the spindle why not use an R8 blank end arbour ? There is nothing sacrosanct about the size of the centre hole. You would have to be able to put the arbour into the lathe chuck (4Jaw) and ensure that it is true. Then turn it down to the size you want. Then after fitting the bar. Then its time to skim the bottom of the bar until it is true to the arbour.

What you say about the hight of the head is correct ! However any slight play in the quill will cause an error. Now you have to decide if that error is acceptable.

I've still to finish mine and I'm still waiting for the dial gauges to turn up...:wall:

Yes that will work I just fell if I'm buying one get it with the shoulder so it can be seated and flush. I might just use a straight shank turned from some bar stock I've got. Still trying to get my heat working better in the shop it's in the 20's today but I've managed to keep the shop at 55 deg which is better that the 40's it was at.

 

[BaronJ]

Hi Todd,

As I mentioned I've not finished mine yet. But I will put the bar back onto the lathe faceplate and true it up then skim the shaft down to 14mm so that I can either use it in a 14mm collet or in the 16mm chuck.

I know what you mean about it being a bit cold. You definitely don't want cold fingers, or feet for that matter, whilst operating machinery. The only heating I have is a night frost heater, just to stop things getting so cold that condensation occurs. So far the workshop hasn't dropped below 48F even with the minus 4F (28F) the other morning. 2" inches of insulation all round and 10" in the ceiling helps.

 

[Omnimill]

I've never worked as a machinist but was taught by a time served one to straighten the head on a milling machine by using a piece of bent rod clamped in the quill.
These tramming tools are very pretty (I like buying tools when I can afford them!) and if I had money burning a hole then I might buy one. If I worked in a production environment though I might try to find a quicker way.
A CV joint from a van, trued up in the lathe could be mounted in the quill. Loosten the mill head then raise the table till it comes into contact with the underside of the joint. Tighten the head, job done. Of course, an old CV joint from the breakers yard doesn't look as pretty though does it ...

http://image.made-in-china.com/2f0j...-CV-Joint-Constant-Velocity-Joint-MZ-004-.jpg

Then again you could always make yourself a fancy version. I would if I had the materials and a big enough lathe.

 

[Swifty]

I've always used the "bent rod clamped in a chuck" method, with one indicator. However I can see the benifits of a 2 indicator tramming attachment, it would be so much quicker not having to constantly swing the arm with the indicator to double check the other end.

Paul.

 

[Charles Lamont]

As an aside I also discovered that my mill vice pushed the work piece up on one side a fraction, even though I snugged it down with a leather hide mallet.

Note to self: Must get a decent mill vice !

Save your money. This is normal. Use a roller, or better a 'pull-down' between the moving jaw and the job.

 

[Charles Lamont]

I've always used the "bent rod clamped in a chuck" method, with one indicator. However I can see the benifits of a 2 indicator tramming attachment, it would be so much quicker not having to constantly swing the arm with the indicator to double check the other end.

Paul.

Surely you have to swing this double indicator job round at least once anyway to check it is reading right?

 

[Walltoddj]

I've used the bent rod for years I just fell that I can do a better job and a lot faster with the two indicators. If we wanted to have a true square in the shop we used the Cincinnati Mills or the Hydro ( tell) not the correct spelling it's been a while but the spindle was always ture on those mills because it could not changed.

Todd

 

[BaronJ]

I've used the bent rod for years I just fell that I can do a better job and a lot faster with the two indicators. If we wanted to have a true square in the shop we used the Cincinnati Mills or the Hydro ( tell) not the correct spelling it's been a while but the spindle was always ture on those mills because it could not changed.

Todd

Whilst I can see and appreciate how the bent rod method works it seems a very messy way of doing it.

Re the Cincinnati Mills an their ilk. I went to an auction a little while back there was a couple of big machines and some shapers. Not a single bid for any of them. Crying shame to see the scrappies breaking them up with sledge hammers.

 

[Swifty]

Surely you have to swing this double indicator job round at least once anyway to check it is reading right?

That would be correct Charles, I assume when using them you have to confirm that the indicators are set properly. I never knew that these tramming tools existed until seeing them here. To my knowledge they have never been available from Australian tooling suppliers.

Paul.