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View Full Version : RF45 head tramming mod



loply
04-15-2012, 02:09 PM
Hi folks,

Further to my earlier thread about difficulties tramming (rotating) the head on my RF45 clone, I knocked up these two adjusters so that the head could be adjusted more easily. They are bolted solid to the saddle thing (that slides up and down the Z), and a third bolt is worked in and out to rotate the head. By doing both at once (much like adjusting opposite sides of a 4-jaw chuck) the head can be held in tension and adjusted finely.

I wasn't sure how well this would work but as it turns out it's been brilliant, far better than I could have imagined.

Within literally 60 seconds I was able to get the head trammed to 0.005mm across about an 8 inch span. Furthermore, much to my amazement, the head also didn't move one bit whilst I tightened up the head bolts (previously the indicator would move as much as 0.15mm when doing this!). I think it's also reasonable to assume this may help to keep the head in tram during use too.

Because the adjusters are quite far from the head's centre of rotation the adjustment is very fine.

The adjusters are some old bits of 16mm mild steel solid, drilled through for two M8s to fasten them to the saddle, and then drilled and tapped M8 for the adjuster screw. I used a hand drill to drill the holes into the saddle. The screw ends chew up the paint as you could imagine, and will presumeably chew the iron up a bit, but I may try to acquire some hardened steel discs to use as "washers" per se.

Obviously it will be required to remove them if I ever need to tilt the head for some reason.

It should be noted that in my other thread I also stated that loosening the head completely, spraying in a load of penetrating oil, and then rotating it back and forth by 30 degrees or so loosened the whole thing up a lot, which I think is a pre-requisite to doing this mod.

http://img850.imageshack.us/img850/2072/head1b.jpg

http://img138.imageshack.us/img138/4065/head2o.jpg

hareng
04-15-2012, 03:10 PM
No Z axis locks?

tlfamm
04-15-2012, 04:01 PM
How long are the M8's in the saddle?

loose nut
04-15-2012, 04:06 PM
No Z axis locks?

Other side maybe??

loply
04-15-2012, 05:45 PM
How long are the M8's in the saddle?

About 5mm, leaves a good 10-15mm of space before you hit the saddle dovetails. Made me a bit nervous but I hope the drilling didn't cause a "swell" on the dovetails.

Z-Axis locks are on other other side.

John Stevenson
04-15-2012, 05:59 PM
I really like that idea, good mod.