Delta dp350 drill press Belt falling off

[Peterson white]

I bought a Delta DP350 machine from the market. Every time I start the machine, the belt slips. I've experienced this dozens of times, and it's driving me crazy. The only information I can find is that adjusting the shift lever while the machine isn't running causes this to happen. How can I fix this?

 

[Darren Wright]

That looks very frustrating. I don't have an answer for you, but wanted to welcome you. I'm sure someone here may be able to help though.

 

[Peterson white]

That looks very frustrating. I don't have an answer for you, but wanted to welcome you. I'm sure someone here may be able to help though.

Thank you

 

[Ryan Mooney]

So that's a reeves drive.. I haven't personally suffered with them but will suggest the common things to try..

Check that the front pulley is properly moving in and out..

Make sure both pulleys are well lubricated and moving freely

I think the belt looks maybe? a smidge long for that setup maybe try a slightly shorter belt (it might also have stretched which may make the original belt reading shorter than the current actual perhaps).

 

[Peterson white]

The seller told me that it worked fine when he used it, so the belt is suitable. What is marked in red in the picture? It can swing left and right, about 180 degrees.This is the front wheel.

 

[Peterson white]

The front and rear pulleys are very smooth. The front adjustment lever seems to have no resistance.

Some people say that this is the problem, adjusting the speed lever when not in operation. Is this true?

 

[Don Baer]

I think the split pin (an English mechanic I once knew called it a bloody split pin) might be OK. I haven't seen one used like that but looking at the way it in installed it has to stick out in order for you to be able to remove it. The way I have normally seen them used they are flush and you drive them out by pushing them through but in this instance that would not be possible. I would be tempted to put some vice grips on it and pulling it out being careful not to let the pully move down to make sure it is lined up with a hole in the shaft. The I would drive it back in. You should check the pulley alignment since a google search says that this is often the case. her is more from my google search.

For a Delta DP350 variable-speed drill press, a drive belt that won't stay on is most often caused by a worn-out belt or issues with the variable-speed pulleys. This model's pulleys are known to cause problems as they age.
Before you begin

1. Unplug the drill press. Ensure the machine is disconnected from its power source to prevent accidental startup and injury.
2. Open the belt housing. This will expose the motor and spindle pulleys.
3. Clean the pulleys and belt. Use a rag to wipe away any built-up dust or debris from the pulleys and the belt itself.

Inspection and repair steps
1. Check the belt condition

• Inspect for wear. Examine the belt for glazing (a shiny, hardened appearance), fraying, cracks, or other damage.
• Assess the tension. If the belt is old, it may have stretched, and the variable-speed pulleys may be at the end of their adjustment range. If the belt looks worn, it's best to replace it.
• Consider a link belt. Some owners have found success replacing the original V-belt with a link belt, which reduces vibration and can provide a more secure fit.

2. Inspect the variable-speed pulleys
The DP350 uses a complex variable-speed pulley system with two interlocking halves on the motor and spindle shafts. Issues with this system are a common cause of belt problems.

• Look for binding. With the belt removed, manually check if the motor pulley expands and contracts smoothly as you turn the speed adjustment knob. A pulley half that is expanded too far or binding can push the belt off.
• Check the split pin. On older models, the split pin on the top half of the motor pulley was known to come loose, causing issues. A wire tie can sometimes be used to hold it in place.
• Lubricate the shafts. The pulley system can become sticky over time due to grease buildup. A YouTube video shows that loosening up the mechanism and readjusting the tension can solve the problem.

3. Inspect pulley alignment

• Use a straightedge. Place a straightedge or taut string against both pulleys to see if they are perfectly aligned. If the motor pulley is misaligned with the spindle pulley, the belt will be constantly pushed off.
• Adjust motor mount. If the pulleys are misaligned vertically, you may need to adjust the motor mount. Some models have a hinged motor mount with an adjuster to help with alignment and tensioning.

4. Address spindle issues

• Check for a wobbly spindle. With the belt removed, check for any side-to-side wobble in the spindle. Worn spindle bearings can cause a wobbly pulley that throws the belt.
• Examine the quill. If your drill press has a "wobbly" quill (the part that the chuck extends from), it may not be aligned correctly. Check and adjust the quill's alignment.

 

[Ryan Mooney]

The marked item is a roll pin.. which should .. I believe.. (but also I'm not an expert on Reeves type setups) be pinning that collar in place.

More on the pulleys.. the top of them needs to move up/down to expand/retract the gap which changes the pulley distance. But there also needs to be enough spring resistance so that they don't close all the way. What it looks like is happening is that the belt pressure is coming off of the motor pulley so it closes all the way which causes the belt to slip off. That implies to me that either the belt is just to loose or the spindle pulley is for some reason opening up way to wide.

If the roll pin is letting the collar drop which is letting the bottom of the spindle pulley fall open... that could well do it...

You might have to take that pulley apart to get that collar up enough to get the roll pin back into place. This video is for the motor pulley but I think the same trick for getting the circ clip off of the top would likely work (just be careful the spring doesn't go sprong into an unfindable location..

). If you can lever the bottom of that pulley up (CAREFULLY because as noted they don't make much for parts for these anymore) that might also give enough clearance... If you can do it that way you'll probably have to wiggle things around a bunch to figure out where it lines up (that is find a nice calm day with lots of time.. heh)..

The seller told me that it worked fine when he used it, so the belt is suitable.

I'm reminded of the old farmer who sold his neighbor a mule. The next day the mule dies and the neighbor comes over to complain telling the farmer "that mule you sold me yesterday up and died". The farmer looks at him and sez "huh, that's weird he never did that when I owned him".

 

[Peterson white]

I made a board according to this this morning. Now the only thing I am most proficient in is installing and removing the retaining ring.

 

[Peterson white]

Can the motor pulley be lowered? I manually turned the motor pulley, and after a few turns, the rear wheel compressed. Is the spring pressure too high? Can I lower the height here to reduce the spring pressure?

 

[Don Baer]

The bolt holding the lower pulley in place is just wrong. It should be a proper set screw. The end of the bolt will not work well on the motor shaft. A proper set screw would have a concave cone on the end to allow it to bite into the motor shaft and not spin. You can see where the screw or another screw has spun on the shaft. I learned this the hard way. Here is more information.

The end of a «!nav>>set screw is concave (cup-shaped) to create a ring dentation in the material it's pinning, providing a more secure and reliable hold by increasing surface contact and preventing slippage or loosening due to rotation or vibration. This design concentrates the force onto a smaller area, which bites into the component to lock it in place.

How it works

1. Concentrated Force:
   The thin circumference of the cup exerts pressure over a smaller, sharper area on the component's surface.
   
   
2. Material Deformation:
   This focused pressure causes the harder set screw to deform and bite into the softer material of the component, creating a small indentation or "ring dentation".
   
   
3. Improved Locking:
   The resulting mark acts as a key or anchor, locking the two parts together and resisting relative motion.

 

[Chas Jones]

Some people say that this is the problem, adjusting the speed lever when not in operation. Is this true?

Yes, Reeves Drives need to be rotating to force the sprung loaded pully to respond to belt tension changes.
Manually adjusted pulley needs to be set so that the belt rides near the outer edge when closed.

[edit] Conversely the belt length needs to be such that it rides near the spring pully outer edge when the manual pully is Open.

 

[Dave Hawksford]

So this in my 51 craftsman it's very similar.
1st pic with tension, 2nd Pic without tention.
I do like simple.

 

[Vaughn McMillan]

Based on the wear marks, I suspect the bottom half of the split pulley needs to be adjusted to where it's lower on the shaft.

So this in my 51 craftsman it's very similar.
1st pic with tension, 2nd Pic without tention.
I do like simple.

It's not similar at all. Peterson's drill press has a Reeves drive, which is a completely different animal.

 

[Peterson white]

There should be two cotter pins, one stuck in the lever groove on both sides.

 

[Peterson white]

I bought a new belt on eBay. Now when it runs, the belt vibrates violently. I can see irregular belt jumping and rubber dust in the belt guard. In fact, this is abnormal wear.
I have added grease to the motor shaft and the main shaft. Do I need to add some lubricant to the pulley?

 

[Jay Caughron]

My thought are you need a V-belt without the splines

 

[Peterson white]

我认为开口销（我曾经认识的一个英国机械师称之为血腥开口销）可能没问题。我从未见过这样使用的，但看它安装的方式，它必须伸出来才能卸下。我通常看到它们的使用方式是齐平的，你通过将它们推过去将它们推出，但在这种情况下，这是不可能的。我很想在上面放一些虎钳并将其拉出，小心不要让滑轮向下移动，以确保它与轴上的一个孔对齐。然后我会将其推回。您应该检查滑轮的对齐情况，因为谷歌搜索表明情况通常如此。这是更多来自我的谷歌搜索的内容。

对于 Delta DP350 变速钻床来说，传动带无法保持啮合通常是由于皮带磨损或变速皮带轮出现问题造成的。众所周知，这种型号的皮带轮会随着老化而出现问题。
开始之前

1. 拔掉钻床的插头。确保机器与电源断开，以防止意外启动和受伤。
2. 打开皮带外壳。这样就能看到电机和主轴皮带轮。
3. 清洁滑轮和皮带。用抹布擦去滑轮和皮带上积聚的灰尘或碎屑。

检查和维修步骤
1.检查皮带状况

• 检查磨损情况。检查皮带是否有光泽（闪亮、硬化的外观）、磨损、裂纹或其他损坏。
• 评估皮带张力。如果皮带老化，可能已经拉伸，变速皮带轮的调节范围也可能已经到了极限。如果皮带看起来磨损严重，最好更换。
• 考虑使用链式皮带。一些车主发现用链式皮带替换原来的V型皮带很有效，这样可以减少振动，并提供更牢固的配合。

2.检查变速滑轮
DP350 采用复杂的变速皮带轮系统，电机轴和主轴轴上有两个互锁的半轴。该系统出现问题通常是皮带故障的原因。

• 检查皮带是否卡住。拆下皮带后，手动检查电机皮带轮在旋转速度调节旋钮时是否能顺畅伸缩。如果皮带轮伸缩过度或卡住，可能会将皮带推断。
• 检查开口销。老款电机皮带轮上半部分的开口销容易松动，从而导致问题。有时可以用扎带将其固定到位。
• 润滑轴。滑轮系统会因为油脂堆积而随着时间的推移变得粘稠。YouTube上的一个视频显示，松开机械装置并重新调整张力可以解决这个问题。

3. 检查滑轮对中

• 使用直尺。用直尺或绷紧的绳子抵住两个皮带轮，检查它们是否完全对齐。如果电机皮带轮与主轴皮带轮错位，皮带就会不断脱落。
• 调整电机支架。如果滑轮垂直方向未对准，则可能需要调整电机支架。有些型号配有铰链式电机支架，并配有调节器，有助于对准和调整张紧度。

4. 解决主轴问题

• 检查主轴是否晃动。拆下皮带后，检查主轴是否左右晃动。主轴轴承磨损会导致皮带轮晃动，从而导致皮带脱落。
• 检查钻床的主轴。如果钻床的主轴（卡盘伸出的部分）“摇晃”，则可能未正确对齐。检查并调整主轴的对齐情况。

Thank you!

 

[Peterson white]

标记的物品是一根卷针......我相信......它应该......（但我也不是 Reeves 类型设置的专家）将衣领固定到位。

关于皮带轮……皮带轮顶部需要上下移动来扩大/缩小间隙，从而改变皮带轮距离。但同时也需要足够的弹簧阻力，以免它们完全闭合。目前的情况是，皮带压力从电机皮带轮上脱落，导致电机皮带轮完全闭合，从而导致皮带滑落。在我看来，这意味着要么是皮带松了，要么是主轴皮带轮出于某种原因张得太大了。

如果滚销让套环掉落，从而使主轴滑轮的底部掉落......那就很可能会发生这种情况......

你可能需要拆开那个滑轮，才能把那个卡圈抬高到足以把滚销放回原位。这个视频是关于电机滑轮的，但我觉得用同样的技巧把顶部的环形夹取下来应该也行（只是要小心，别让弹簧弹到找不到的位置……

）。如果你能把滑轮的底部撬起来（要小心，因为之前说过现在这类零件已经很少生产了），这样也能留出足够的空间……如果你能用这种方法撬起来，你可能需要不停地摇晃才能找到它的位置（也就是说，找个时间充裕、风平浪静的日子……呵呵）。



这让我想起了一位老农夫，他把一头骡子卖给了邻居。第二天，骡子死了，邻居跑来抱怨农夫：“你昨天卖给我的那头骡子死了。”农夫看着他，说道：“啊，真奇怪，我养它的时候，它从来没死过。”

Thank you!

 

[Peterson white]

My thought are you need a V-belt without the splines

The smooth belt on the machine I bought second-hand was unstable, so I bought this one on eBay. It didn't work either, it was too tight.