Thursday, October 15, 2015

3131 - Hare and Forbes HM-50 / TopTec Milling machine - Richard Muller - Australia

Hare and Forbes HM-50 / TopTec Milling machine

From Richard: 
Received the DRO Kit 6 days after I ordered it, excellent delivery and speed of delivery, and packaged well. Just finished installing it onto my Turret Mill and works well.

I’m not sure where to leave feedback on your product but would recommend this site to others and the prices are half what everyone else is selling here in Australia and America.

I ended up making my own brackets for some of the install as it was awkward to install the scales neatly (what mill isn’t).

The only issue I had was the female screw threads in the back of the readout for the plugs some screws just fell into the holes, seemed either the female thread was oversized or the screws in the plugs undersized, but easily fixed with some different screws.
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Thank you so much for the information, I am sure it will help fellow DRO installer.

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This is a common Turret mill sold in Australia and overseas that is made in China.
Hare and Forbes sell this mill as a HM-50, I bought mine a few years ago from another company
in Adelaide.


I have as best I could added some Tips along the way to guide you in the right direction to take on some parts of the install to make some areas easier for you.
Hope this will help you when installing your DRO.


I have not put any measurements into the pictures either as everyone will have there own way of mounting the Dro Kit.


Although well made I did not use the mounting kit supplied opting to make my own, basically I have other planes for them on another project, all screws and other hardware supplied was used.

 






X axis Tip
As the Scales do not have squaring adjusting screws, I found making two 8mm packers and fixing to the knee side where you wan t to affix the Scale and bolt in place.
1. Install the drop plate with a 10mm or 3/8” hole roughly 25mm above the scale mounting blocks centre line making sure it is square with a 5mm packer behind it.

2. From some 32 x 25 tube about 200mm long (used for fencing rails) with a step drill, drill a large hole on one end on both sides to receive the Dremel grinder male thread.

3. Drill a 10mm or 3/8” hole 150mm back from the large hole end all the way threw and remove the burs.

4. Install the Dremel Grinder into the end making sure the female cap is inside the tube and tighten up by turning the grinder , the nut shouldn’t turn.

5. Using a 3mm or 1/8” end mill set the depth of cut require by either cutting of some of the end mill or sliding back into the collet just enough the remove the aluminium down to the
lowest spot. If you don’t have a 3mm end mill bit as I did use a new 1/8” drill and grind off the cut end to length with a sh arp edged grind wheel, put some back relief into the bit with a 2
Degree dish angle and this will work. Be careful doing this with a drill bit and only take very light cuts or you will break the bit.

6. Bolt the jig to the outer side of the drop plate and tighten the bolt enough to keep firm, do not use washers between the two faces.

7. Turn on the Dremel grinder and starting at the top of the block “Carefully” wind the X axis across the block on one end it will cut square to mount blocks for the scales. Just tap the jig
down a little and repeat until done.
You will need to file off the nub underneath the bolt afterwards. Don’t forget to mark your blocks top back and top front you don’t want t o undo all your hard work.

8. To do the other end just rotate the jig assembly 180 degrees and do the same but don’t change your bit length. I was only . 001” out doing this on the X travel and zero across the Scale.
This may seem quite a long process to do but only took me ¾ of an hour from making the jig and milling the brackets also saved a lot of stuffing around getting the brackets square
and true on an uneven surface.
 



  
Tip, with the top Z scale mount spacer, don’t try and get the bracket angle too the scale to exactly match the full width or the scale mounting face. If your slightly out and you tighten it up it will bow the scale straining it in its longitude travel causing bad runout and will be impossible to set it up with a dial indicator. 

Just get it as accurate as possible in both the X and Y directions and then slightly round off the top and bottom of the face side leaving about 6mm of flat surface in the middle to clamp against, this may include the bottom bracket as well.
 



  

Tip, with the top Z scale mount spacer, don’t try and get the bracket angle too the scale to exactly match the full width or the scale mounting face. If your slightly out and you tighten it up it will bow the scale straining it in its longitude travel causing bad runout and will be impossible to set it up with a dial indicator. Just get it as accurate as possible in both the X
and Y directions and then slightly round off the top and bottom of the face side leaving about 6mm of flat surface in the middle to clamp against, this may include the bottom bracket as well.
 


  
  
It’s a good idea to make two crush tubes for the Digital Read Out mount arm and insert them at each end, otherwise, your going to damage/deform the arm tightening it up and could snap the mount bracket as well, plus you'll never get it tight enough anyway.
 


 


















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