A Height Adjusting Toolpost
1
ADJUSTING TOOLPOST By James Smith T HIS DEVICE REPRESENTS a method of lathe tool height adjustment and though I do not claim originality, I cannot recall having seen the idea published before. I have been using this tool holder nearly seven years, and it has not given me the slightest trouble. In fact, it has saved me considerable time in tool setting. The holder itself is simply an improvement on the Drummond split toolbox type, which clamps to a pillar, cast integral with the topslide. This pillar on my lathe has a 1/2 in. Whit. tapped hole in the centre about I 1/2in. deep-for what reason I am not sure unless it was for holding the slide in a jig, the pillar having been turned first while the vee-slides were machined. However, I thought that the tapped hole could be used for tool height setting, so the improved tool holder was evolved. Would not reach centre The original toolbox had a square hole for the tool, which, when using a right- or left-hand cranked tool, meant bringing the cross-slide well out or turning the box almost through 90 deg. I did not like this at all. And when the toolbox was set with the square hole parallel to the bed for boring and the cross-slide was screwed in as far as it would go, the toolbox would not reach the centre unless I took off the whole topslide and put it in the farthest tee-slot. So I decided to make a new one with screw-height adjustment,, and which would reach the centre without the necessity to change to another tee slot. The modified toolbox is made out of a block of cast steel, but cast iron would do just as well. The split bush is made of mild steel and the ring of holes under the bolt head is for turn- Side elevation of the tool holder I I ‘=I- / I \ Top Right: Plan view Right: Sectional view SQUARE FLANGED COLLARED PILLAR P LLAR t 4 FINE THREA- SCREWED ,IN FOP REST End elevation of the holder 1 m TOP REST I I I , Below right: Sectional plan ing back the clamping-bolt should there be any thread stretching, thus the nut handle is always about 45 deg. off vertical. The drawing will show how simple the adjustments are. Personally, I do not like any tool holders in which the front and top rake angles are altered so as to obtain dead centre. This improved tool holder is only adaptable at present to the Myford Drummond,. but it would be easy to fasten a 1 1/4 in. dia. pillar either with a square flange or shouldered and screwed with a fine thread to many existing lathes. I am surprised that this simple holder has not been thought of before. I can assure readers that it is quite solid when taking very heavy cuts. q 31 l III t_ 5 JULY 1956 MODEL ENGINEER
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Transcript of A Height Adjusting Toolpost
ADJUSTINGTOOLPOSTBy James Smith
TH I S D E V I C E R E P R E S E N T S amethod of lathe tool heightadjustment and though I do
not claim originality, I cannot recallhaving seen the idea publishedbefore.
I have been using this tool holdernearly seven years, and it has notgiven me the slightest trouble. Infact, it has saved me considerabletime in tool setting. The holder itselfis simply an improvement on theDrummond split toolbox type, whichclamps to a pillar, cast integral withthe topslide.
This pillar on my lathe has a1/2 in. Whit. tapped hole in the centre
about I 1/2in. deep-for what reasonI am not sure unless it was for holdingthe slide in a jig, the pillar havingbeen turned first while the vee-slideswere machined. However, I thoughtthat the tapped hole could be usedfor tool height setting, so the improvedtool holder was evolved.
Would not reach centreThe original toolbox had a square
hole for the tool, which, when usinga right- or left-hand cranked tool,meant bringing the cross-slide wellout or turning the box almost through90 deg. I did not like this at all. Andwhen the toolbox was set with thesquare hole parallel to the bed forboring and the cross-slide was screwedin as far as it would go, the toolboxwould not reach the centre unless Itook off the whole topslide and put itin the farthest tee-slot.
So I decided to make a new onewith screw-height adjustment,, andwhich would reach the centre withoutthe necessity to change to anothertee slot.
The modified toolbox is made outof a block of cast steel, but cast ironwould do just as well. The split bushis made of mild steel and the ring ofholes under the bolt head is for turn-
Side elevation oft h e t o o l h o l d e r
I I ‘=I-/ I \
Top Right: Plan view
Right: Sectional view
SQUARE FLANGED COLLARED PILLAR
P LLARt 4
F INE THREA-SCREWED ,INFOP REST
E n d e l e v a t i o nof the holder
1 m
TOP REST I
I I,
Below right: Sectional plan
ing back the clamping-bolt shouldthere be any thread stretching, thusthe nut handle is always about45 deg. off vertical. The drawing willshow how simple the adjustments are.Personally, I do not like any toolholders in which the front and toprake angles are altered so as to obtaindead centre.
This improved tool holder is onlyadaptable at present to the MyfordDrummond,. but it would be easy tofasten a 1 1/4 in. dia. pillar either witha square flange or shouldered andscrewed with a fine thread to manyexisting lathes.
I am surprised that this simpleholder has not been thought ofbefore. I can assure readers that it isquite solid when taking very heavycuts. q
31
l III
t_
5 JULY 1956 MODEL ENGINEER
