Shopsmith Forums

I was using the brad point SS bits, (1/2"), cutting blind holes in pine board. Preset all depths and location of fence in a scrap board. When I drilled my first hole in the good stock, the hole was short of the depth needed.
After resetting the depth from the test piece, I drilled the first one to depth, and drilled the next hole. This hole was also shy of the original depth. Each time the hole seemed to be 1/8 or so shy of the depth originally set.

I check all items to ensure that everything was locked tight, drill bit, head unit, table, and depth control. I don't know what would of kept changing as I have used this same type of setup in the past.

Any help would be great, as I did not like having to re-adjust each time, creating a possible issue in getting them aligned each time.

Thanks

Some folks have observed a flex in the fence, especially on the 510. The 520 fence is reported to be a lot more rigid during boring (that is horizontal boring) operations. That would be one reason I may upgrade one day....

Good luck,

Hi blackace - In the past, I've had the same problem. It was found to be caused by a slippage of the carriage down the way tubes. I temporarily (for more than a year) solved this problem by sliding the carriage all the way to the right before drilling anything. The slippage stopped - and also the problem of progressively shallower holes - because there was nowhere left for the carriage to slip. This also caused me to do all drilling sitting on a stool.(no back ache ) As this was comfortable, I didn't look for another solution. I would have tightened the locking bar, but it was already tight.

Now, the solution is to put a large block of wood beneath the carriage when in drill press mode. Real soon, because of using the OPR I will be using a bottle jack, like Nick does in the sawdust sessions.

One other thing to look at.

Set the depth for the lower part of the tip of the drill bit (sorry but I don't have PTWFE in front of me to give the proper names for parts of a brad point drill bit). You may have measured to the tip of the spur which only cuts a circle in the wood you need to measure to the part that cleans the wood out of the circle.

Just a thought,

Put a couple of tubes in the table and use your adjustable support legs to stabilize the front of the table. (that's assuming you have a 510 or 520) With a 500, you could support the carriage with a board wedged between the carriage and the hinged end of the SS.

Hi,
Try the Shopsmith Table Support Leg #555627. I have a couple and they really help stabilize my 500 table.
ldh

Have we lost track of the stated problem (question)?

The established drill depth is not being maintained; the hole is getting shallower with each successive hole.

I don't see how table instability could cause this.

I do see how the headstock slipping down on the tubes COULD be the culprit. Others have reported this problem and the solution has been to fix the headstock lock mechanism or to "block" the headstock so that it could not slip. I prefer and would recommend fixing the headstock lock.

Dusty,
Sorry, I forgot to say I also add a cleat between my main table and the RH table.
ldh

Hi,
You can quickly check for headstock or carriage creep by simply placing a mark on the front way tube 1" left of the headstock and 1" to the right of the carriage. Drill a few holes and If you have a change in one or both of the 1" measurements you have creep. The SS manual has the repair information.
ldh

Thanks for all the suggestions. I will check to see if anything is moving and fix that if it is the case.

With having a 500 model, the support legs are not an option. The brace under the table and a stool seem more my speed.

I will let you know what I find out. I am in the process of putting the finish on the project. In the worst case, I can use my drill press for this task, just did not want to use it as it is more a metals tools not a wood tool. Just means I would have to clean all the cutting fluids off the table and all.

Thanks again.