Shopsmith Forums

There has been a theory, held by some, that the rubber baby bumper on the Way Tube of the Mark V was there was a shock absorber for when the headstock slams down on that end when placed into the drill press mode. It all sounded pretty logical to me. So logical that I bought two new ones for use on the Double Tilt when I finished it.

Then it dawned on me that Rubber Baby Bumpers do not come with the Double Tilt Upgrade.

Is this because Shopsmith failed to recognize the need or is it just possible that the theory has been wrong all along and their only purpose is to space the carriage away from the headstock some prescribed amount. If the right size, this just might position the blade right smack in the center of the table saw insert opening.

If that is the case, the two new bumpers that I received with this last order are wrong. Well, maybe not wrong but they are different than the last two I got. Those are on my Shorty.

Shock Absorber or Spacer or Neither?

Spacer, in my opinion. And Shopsmith probably doesn't provide one with the Double Tilt Upgrade because you already should have one if you own an Shopsmith you are upgrading. It is only necessary between the carriage and headstock and hence one is enough.

Are the new one's too big or small? Too big means they can be trimmed to length after alignment?

The only upgrade I did with the rubber baby bumper as part of the kit was from the 500 to the 520. In that case you needed it. When I did the 510 to 520 no bumper was included and did not need to be since the 510 and 520 tables are located in the same place and have the same bumper.

The dual tilt kit could be used on a 500 I guess??? Not sure if the new table legs would work but the ends would. I think of it as an upgrade to a 510/520. In either case what ever bumper you have would stay the same.

Ed

dusty wrote:There has been a theory, held by some, that the rubber baby bumper on the Way Tube of the Mark V was there was a shock absorber for when the headstock slams down on that end when placed into the drill press mode. It all sounded pretty logical to me. So logical that I bought two new ones for use on the Double Tilt when I finished it.

Then it dawned on me that Rubber Baby Bumpers do not come with the Double Tilt Upgrade.

Is this because Shopsmith failed to recognize the need or is it just possible that the theory has been wrong all along and their only purpose is to space the carriage away from the headstock some prescribed amount. If the right size, this just might position the blade right smack in the center of the table saw insert opening.

If that is the case, the two new bumpers that I received with this last order are wrong. Well, maybe not wrong but they are different than the last two I got. Those are on my Shorty.

Shock Absorber or Spacer or Neither?

We will probably never know since the person that came up with the idea is probably no longer with us. A shock absorber seems more logical since the width varies by a fair amount. However, if that is/was the intent I would think there would be two. How wide are the ones you just got? My bought new in '94 510 was 1 1/4" (I still have it). It did not center the blade. I got a new one from the MS in about '96 when I mentioned it to them. It is 1 7/16". I think JPG said his is 1 3/8".

So they are all over the place. Seems to me to be too much deviation for a spacer.

However we have to look at Magna for clues. I have an original Magna Engineering copy of the preliminary manual shipped with the first 10E's.

Page 6 talks about a spacer "bolt" for table saw mode. That to me suggests that the rubber bumper is for that same purpose. I assume the Magna made MK 5's had the bumper and it was not introduced later.

It still begs the question why the width dimension is all over the place if it is supposed to be a spacer.

Perhaps it would be interesting if more people did a measurement and posted here. If you know the date that would be wonderful as well.

My newer machine which was upgrade from at 500 to 520 has a measurement of 1-7/16, the older one which was a 500 upgraded to a 510 before I got it has a measurement of 1-3/8.

Anyone else?

Ed

jsburger wrote:

dusty wrote:There has been a theory, held by some, that the rubber baby bumper on the Way Tube of the Mark V was there was a shock absorber for when the headstock slams down on that end when placed into the drill press mode. It all sounded pretty logical to me. So logical that I bought two new ones for use on the Double Tilt when I finished it.

Then it dawned on me that Rubber Baby Bumpers do not come with the Double Tilt Upgrade.

Is this because Shopsmith failed to recognize the need or is it just possible that the theory has been wrong all along and their only purpose is to space the carriage away from the headstock some prescribed amount. If the right size, this just might position the blade right smack in the center of the table saw insert opening.

If that is the case, the two new bumpers that I received with this last order are wrong. Well, maybe not wrong but they are different than the last two I got. Those are on my Shorty.

Shock Absorber or Spacer or Neither?

We will probably never know since the person that came up with the idea is probably no longer with us. A shock absorber seems more logical since the width varies by a fair amount. However, if that is/was the intent I would think there would be two. How wide are the ones you just got? My bought new in '94 510 was 1 1/4" (I still have it). It did not center the blade. I got a new one from the MS in about '96 when I mentioned it to them. It is 1 7/16". I think JPG said his is 1 3/8".

So they are all over the place. Seems to me to be too much deviation for a spacer.

However we have to look at Magna for clues. I have an original Magna Engineering copy of the preliminary manual shipped with the first 10E's.

Page 6 talks about a spacer "bolt" for table saw mode. That to me suggests that the rubber bumper is for that same purpose. I assume the Magna made MK 5's had the bumper and it was not introduced later.

It still begs the question why the width dimension is all over the place if it is supposed to be a spacer.

I'll have to measure it again. I did but do not remember. I do know that the ones today were just a tad larger than what I already had.

dusty wrote:

jsburger wrote:

dusty wrote:There has been a theory, held by some, that the rubber baby bumper on the Way Tube of the Mark V was there was a shock absorber for when the headstock slams down on that end when placed into the drill press mode. It all sounded pretty logical to me. So logical that I bought two new ones for use on the Double Tilt when I finished it.

Then it dawned on me that Rubber Baby Bumpers do not come with the Double Tilt Upgrade.

Is this because Shopsmith failed to recognize the need or is it just possible that the theory has been wrong all along and their only purpose is to space the carriage away from the headstock some prescribed amount. If the right size, this just might position the blade right smack in the center of the table saw insert opening.

If that is the case, the two new bumpers that I received with this last order are wrong. Well, maybe not wrong but they are different than the last two I got. Those are on my Shorty.

Shock Absorber or Spacer or Neither?

We will probably never know since the person that came up with the idea is probably no longer with us. A shock absorber seems more logical since the width varies by a fair amount. However, if that is/was the intent I would think there would be two. How wide are the ones you just got? My bought new in '94 510 was 1 1/4" (I still have it). It did not center the blade. I got a new one from the MS in about '96 when I mentioned it to them. It is 1 7/16". I think JPG said his is 1 3/8".

So they are all over the place. Seems to me to be too much deviation for a spacer.

However we have to look at Magna for clues. I have an original Magna Engineering copy of the preliminary manual shipped with the first 10E's.

Page 6 talks about a spacer "bolt" for table saw mode. That to me suggests that the rubber bumper is for that same purpose. I assume the Magna made MK 5's had the bumper and it was not introduced later.

It still begs the question why the width dimension is all over the place if it is supposed to be a spacer.

I'll have to measure it again. I did but do not remember. I do know that the ones today were just a tad larger than what I already had.

I think the variance is simply the MS being sloppy.

Historically the spacer was a threaded rod(on the Greenie) that was adjustable. Unfortunately it also acted as ram rod when failing to lock the headstock prior to raising and that caused the carriage(with the hole the rod was threaded into) to become broken.

So it was eliminated with the Goldie(or about then) and the hard 3/8" spacer was added.

Then the 505-510...520 redesign took place and the spacer became a rubber tube. As for the length, the purpose is still to center the blade in the slot.(± ?) The table and carriage both contribute to the amount of length change.

My 1 3/8" one was obtained 'used' and the history is unknown(it replaces one that was shortened by becoming bowed out).

As a 'bumper' it is woefully inadequate. MHO

P.S. adjusting the table in the trunion mounting holes will shift the 'center' of the slot so there is some possible variance for dead centering. Also the ends butt against non-precision surfaces that are not even parallel to each other.

The part you are referring to for the Model 500 is called Stop Ring with part number 516666. It is not very wide at all and enables the saw blade to be centered in the table slot. The one for Models 505/510/520/Mark 7 is called Carriage Stop Ring with part number 516667. It is wider and also enables the saw blade to be centered in the table slot. That is the only purpose. If you have lost yours or never had one, you can buy one.

I do have the double tilt on my Model 500. My table also can be reversed for under table shaping contrary to what Shopsmith says is possible. I have a separate posting that details the procedure.

http://www.shopsmith.com/ss_forum/maint ... 12064.html

BTW the Mark VII used a very long rod attached to the carriage with a detent groove that referenced them to the headstock. That allows 'ganged' movement of them together. Still no stupidity bumper.

Here is mine. Mark 7, March 2015