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Thread: Delta/Rockwell 12 inch RAS question.

  1. #1

    Delta/Rockwell 12 inch RAS question.

    I have a Delta radial arm saw that I am fixing up. Everything works as it should except for the elevation crank.

    I have not seen one of these in person before so I have a question to someone who has one.

    There is about 3/4 of a turn of "slop" in the elevation crank adjustment. When I crank it up, the head does move up (it feels stiffer that I think it should). When I go to lower it, I can turn the elevation crank almost 3/4 of a turn before it starts moving the head down. The elevation mechanism is turning the vertical lead screw with NO slop. Its like the elevation lead screw has to pull the head down.

    My previous RAS was a Craftsman and it seemed that there was no "slop" in the elevation crank. If I recall correctly, it seems that the weight of the head provided the downward movement of the head, not the lead screw pulling the head down.

    This is an older saw that has seen limited usage so I am thinking that the column is not moving freely enough. Probably dried up grease. I put some kroil brand oil on the shaft to try to loosen it up. Didn't seem to help much.

    So...... 3 questions.

    1. Should there be any "slop" in the crank mechanism when changing from going one direction to the other?
    2. Should the lead screw be pulling the head down, or should gravity be providing the force?
    2. How hard is it to put the spring loaded pin back in the vertical column should I decide to remove the column? (that's the round disk with 3 bolts)

    Anyone have a guard for this saw? I need to buy / make one.

    Thanks,
    Frankie

    Delta RAS.jpgRAS rear.jpg
    Last edited by Frankie Hunt; 08-27-2017 at 9:12 PM.
    Frankie

    I have a great Border Collie, she just can't hold her licker!

  2. #2
    Join Date
    Jan 2013
    Location
    Western MA
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    52
    Might want to try posting at old woodworking machines also. I have a similar saw which does not have the lag you describe. Keep lubricating and working it if it has been used little or not at all for an extended period of time.

  3. #3
    Join Date
    Mar 2007
    Location
    Tidewater, VA
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    273
    I do not have one. What you describe could be excessive drag between moving parts. It appears the column rises and retracts within the bore of the cubic base. As matter of design and manufacture, the column must be smaller than the bore and there should be some means to take the slack to zero and to lock a selected height.
    In the two photos offered I do not see a vertical slit to be clamped by a bolt as in a drill press quill or column. I will guess that the steel hockey puck on the back of the column base could provide, one or both, indexing for the arm and slack/drag for the vertical travel.

    Just one duffer's guess... Crack tension on each of the puck's three bolts; no need to back them off. If this gives some relief, you have it. If no relief, tighten them up and go to owwm.org for a manual.

    BobV

  4. #4
    Adjustment handle on front?
    Bevel gears?

  5. #5
    Join Date
    Dec 2005
    Location
    West Lafayette, IN
    Posts
    6,529
    The slop you're referring to is backlash I believe. Nothing to do about it. Mine is similar.

    I restored a 33-890 and cleaning up the column did a lot for the ease of up/down movement. Given, I had it completely taken apart and cleaned, which I doubt you're planning on. Maybe just raise it all the way up, clean and scrub it with scotch brite then lubricate would help.

  6. #6
    Matt,

    I think I will take the column apart. I have the manual downloaded for the saw. It says " The shear pin on the handle will protect the bevel gears in the raising mechanism should you continue cranking the handle after elevating to the top position"

    So.... My question is. How is the column dissembled?

    I will remove the motor and yoke. There must be some kind of stop limiting the elevation. Is that the spring loaded plug on the rear of the column that rides in the slot? Once that is removed can you just continue raising the column until it comes off of the lead screw? or does the lead screw have a head? Or how is the column removed???
    Frankie

    I have a great Border Collie, she just can't hold her licker!

  7. #7
    I re posted over at OWWM.

    I pulled the manual from that site this past weekend.

    There is minimal backlash on the bevel gear mechanism. It turns the vertical lead screw fine. The problem is the vertical lead screw takes about 3/4 of a turn before it starts moving the column every time you change directions from up to down or visa versa. (same as the front handle)

    I think the column is not moving freely enough.

    That puck on the rear of the column holds in a spring loaded plug that fits in a slot on the column. I backed it out and oiled the puck but that didn't seem to help much. The plug is what keeps the column in alignment.

    Looking at the parts diagram, it looks like I could remove that plug and then turn the lead screw until it backed totally out of the column. The lead screw engages the column via a tapped cylinder. The diagram doesn't show any C clips or other retaining devices, but it is not a real detailed picture in the diagram.
    Frankie

    I have a great Border Collie, she just can't hold her licker!

  8. #8
    Join Date
    Jun 2007
    Location
    Bastrop, TX
    Posts
    182
    Don't whatever Frankie found or fixed! I bought my D-R model 33-890 about 8 years-ago ... it was a little 'sluggish' to the elevation crank. When it all-of-sudden a month-ago stopped moving altogether the only thing-to-do was to dismantle-it. I found that the elevation 'nut' was aluminum and had stripped-out and that it's steel replacement was no longer available. I made a sketch and took-it to a local machine-shop ... the owner wasn't sure if they had a 5/8-8 LH Acme tap and/or where it might be. The most expedient $cost-effective thing-to-do at the time was to buy a nut from McMaster Carr. As I was putting it back together I had 2nd-thoughts about that I should've contacted OWM.

    2024-03-EleNut.JPG

  9. #9
    Join Date
    Feb 2014
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    Lake Gaston, Henrico, NC
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    Did you lube the column? Sounds like some slop somewhere in the system, but lubing should help.

  10. #10
    Join Date
    Jun 2007
    Location
    Bastrop, TX
    Posts
    182
    Nope, no slop ... it takes a very exacting push or pull to move the column free-hand without the crank. When I bought-it I did the usual clean-and-lube: cranked the column all-the-way-down ... squirted lube-with-teflon all-around ... cranked the column all-the-way-up ... squirted again ... repeated several times. I try to reserve Sunday afternoons for sharpening, waxing and all-purpose maintenance ... the column got squirted every few months.

  11. #11
    Join Date
    Feb 2014
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    Lake Gaston, Henrico, NC
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    I was meaning slop in the rack and pinion mechanism.

  12. #12
    Join Date
    Jun 2007
    Location
    Bastrop, TX
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    182
    Thank you, Tom ... in re-thinking the aluminum 'nut' failure from your comments I realized that the part failed because it went dry from not having any lubrication. And though I now have a steel nut and screw that were lubed at assembly, I'm guessing that as that lubrication thins-out the same thing is likely to happen. There is not any way that the nut and screw can be lubricated once assembled. No matter how much lubricant is applied to the column, there's not any way that it can get to the nut and screw. The only thing-to-do is to take it apart ... UGH ... and drill a access hole in the column base to periodically lube the nut.

  13. #13
    Join Date
    Feb 2014
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    Lake Gaston, Henrico, NC
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    How about a grease fitting with a hole targeting the area it needs to get to?

  14. #14
    Join Date
    Sep 2016
    Location
    Modesto, CA, USA
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    9,882
    Be very careful about removing the main lift screw. Once it is gone the entire weight of the saw may come down on your head and hands. Stack some safety blocks on the table under the arm to catch it.
    How often will you adjust the cut depth? Me I would set it to cut below flush on the table and never touch it. Maybe to swing the saw for angle cuts or change a blade. I do not dadoe on the RAS
    Bill D
    Last edited by Bill Dufour; 03-21-2024 at 1:24 PM.

  15. #15
    Join Date
    Jun 2007
    Location
    Bastrop, TX
    Posts
    182
    Tom: Grease fitting would have to be at the 'nut' needing a large access 'port' through the base column and the elevation column. I'll be drilling a 1/4" hole through both for a lube can straw that'll reach to the nut-screw juncture.
    Bill: your right ... that kind of dis-assembly would be a major danger to head-and-fingers! However; the structure requires that you take the upper-assemblage off and the actuation-gears below before you can remove the elevation column with the 'nut' in-it. For the dis-assembly I laid it on it's side with support blocks. About 95% of the time I do like you: set the overarm for a 90* cross-cut with the blade about 1/32" below the table surface. Any angle cuts are handled using a sine-bar. On occasion I do use it to cut dadoes ... it's much easier to mount the dado stack into then my Robland combo machine which is a pita for evn changing just the saw blade.

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