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Shape Rite 8" shaper mods

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erokc

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#1
I have had too much time on my hands while waiting for delivery of an early model Shape-Rite. I have studied many pictures and I think I can make three modifications that will be useful. I am speculating that these ideas will work. If anyone has made any of these please let me know.

1. It needs a clutch. The larger machines all have clutches for obvious reasons but a small machine could be safer and easier to operate with a clutch.
While running if the motor mount was raised it should cause the drive belt to slip and if there is enough friction in the moving parts the ram should stop in a short time.
If that is true an arm attached to the motor mount extending toward the center of the machine on the right side could be used to start and stop ram motion.
A vertical arm with a concentric against the first arm would allow a forward/rearward motion to engage/disengage the belt tension.

2. Vertical table feed. Who wants to have their hand on the tool head handle while the machine is running.
If it is possible! Move the table vertical height shaft from the left side to the right side. That should put it next to the horizontal feed shaft. Gear connect the two shafts.
Make the ratchet mechanism switchable between the two shaves, ie. disengage one shaft and engage the other to switch feeds.

3. Self stopping at the end of a pass.
I plan to put adjustable limit switches on the table travel. I like to let a machine run while I work on another task.
That would require a motor relay that is held on through the NC contacts of the switches.

After I get my machine I will look at the three mods in more detail and follow up with my plan. If anyone has done these please save me some time designing the changes.
 

francist

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#2
Yes, I have done the equivalent to your Modification 1 and designed a slack belt clutch for my 8" Peerless shaper. It works very well.

One thing I found out right off the bat though was that I needed to add a couple of guide channels at the centre chords of the belt. Without the guides, when I took the tension off the belt would want to relax into more or less a circular shape. This still put enough drag on the sheaves that the ram would still be in motion although very weakly. With the guides though the belt is restricted to a more oblong shape (the channels keep the belt "squeezed" as it were) so that the slackness is forced to appear at the two pullies. This gives the required clearance so there's no longer any drag on the sheaves. Result: the belt pulls the drive in and out very cleanly. Here's a couple really quick sketches that might help.

image.png image.png

Other than that I think my design is very similar to what you propose. Coming up with an effective cam shape was probably the most difficult and I got it in the end only by trial and error. My setup also uses an intermediate countershaft as well as a variable pitch pulley drive, so there were some added features to take into account. But, works good so far.

Good luck with yours when you get around to working on it. I'd be happy to help out more if I can when you get there.

-frank
 

Janderso

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#3
The green and orange drawing reminds me of a timing chain and guides on a car engine.
 

erokc

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One thing I found out right off the bat though was that I needed to add a couple of guide channels at the centre chords of the belt.
I thought about that happening and is why I'm asking. So what I need is four channels top and bottom at the correct angle for the four sheaves. I would think that a little slack stops the drive. Can you nudge the ram to the retracted position with your control? I hate an ON/OFF control on a machine that needs to be set to a desired position.

I'm thinking about a spring to counter the motor weight. Maybe have it near the upper arm pivot point so it crosses over center to hold it in the disengage position. IT MUST NOT EASILY DROP INTO RUN! I'll have to think on this part of it. I'm sure some trial and error is forthcoming, trying for minimum error. The counter spring may be overkill but it must not be easily engaged (RUN).
 

francist

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#5
If you mean jog the ram, yes I can to a degree but not as smoothly or elegantly as you see on the larger machines. Plus, it's the equivalent of riding the clutch so I try not to do it for long. My machine has a nice large handwheel which is the most convenient for me to use if I want to do that.

Yes you are on the right track with dropping out of RUN. Mine does as well. The lever operates a cam through about 100degrees of rotation (just past 90 so it latches ON) which in turn elevates a hinged platform to pull in the drive. Should the lever get nudged or not fully engaged, which has happened, the cam must rotate out and gravity causes the table to fall and the belt goes back into the slack position. That said, I still turn the machine off if I'm doing anything more than just repositioning a feed or cut setting.

-frank
 

benmychree

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#6
Many yard care machines use that method to stop/start motion, it does not need to be a channel, just two rods that restrains the outward motion of the belt when it is slackened. Many shapers have a vertical feed feature for the table, my G&E 24" has a selector lever that engages either vertical or lateral feed. The top bolts on the vertical gibs have double nuts on the top bolts that are adjusted to allow motion without binding and the lower ones have single nuts that hold the knee in locked position.
 

erokc

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#7
I don't have my shaper yet so I can't check this idea. There are two, four step pulleys and I think at the mid point between pulleys the belt position should be the same height for each pair. If so the rod would cross straight across the top and bottom edge of the belt with a little clearance. A simple U shape attached to the housing at the rod ends should do it. Am I on the right track? Just had another thought, put the rods on the pulley cover so when it swings open to change speeds the rods are out of the way.

As for the control lever, I think a short link to the arm attached to the hinged motor base configured to cross over center would have the motor weight to hold it in the disengaged position. As mentioned above any set-up, adjusting or cleaning should be done with the motor OFF.
 
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