My Design

[Simon Thomas]

Threadless rod and nut

Thanks Landuse.

Now I need advice on the modification work to be done as I am not familiar with the threadless rod and nut. The big challenge is how to hold the sprocket and disc brake with the new modified system? With threaded rod may be easy to do, but the threaded rod has some weaknesses and could break due to continuous jerking.

Do you know how to modify my threaded nut / bolt to fit it to the threadless rod? I have plenty in my tool box.

Option 1. Can I use 1" drill bit to drill and remove the nut internal thread?

Option 2. Can I weld the 1" hole internal diameter washers one-by-one and combine them?.

May be you know other part / component from the hardware shop that I can modify as a my new nut.

Please advise if you know. Thanks.

 

[landuse]

I am not too sure exactly how you want to fix it. Could you maybe post a pic of your setup and show where you want to replace the threaded rod. Maybe you can just use pillow blocks.

 

[Simon Thomas]

Sorry if my earlier explanation was not clear enough. Actually, I want to change the broken threaded rod connecting the two rear wheels with a smooth threadless straight rod.

Attached below is the said part.

 

[Benjo]

From what is understand you are replacing your axle with 1" rod, and you want to buy/make some hubs so you can attach your sprocket and brake disk to the axle.

I think you want something like this,

 

[landuse]

Benjo has the answer for you. Get some hubs with keyways to attach your sprocket and brake disk. If getting keys and keyways are too expensive for you to have done, the last resort could be to weld the sprocket and brake disk to the rod. I wouldn't recommend it though because you will never be able to get them off again

 

[Simon Thomas]

Hi Benjo. Thanks for chip-in your idea. It is difficult sometime to find the spontaneous right word to explain the need. That is exactly what I need the "hub".

Landuse. Thanks to you also. I take your advice as well. That would be the last resort like you said and choosing that I would not be able to re-use the rod again.

I need to check whether they have this stuff here. Normally at your place, where could you find this stuff?

 

[landuse]

I had to have all my parts specially machined for me, because there are no gokart shops around here. It took me a long time to find someone that would do it cheaply. What you need to do is find someone with a small machine shop bussiness. If it is just one man working for himself that is even better, because he will not be so expensive.

 

[Simon Thomas]

Difficulty

We are in the same challenge Landuse. It is still difficult to get the go kart / buggy parts here in Sarawak, Malaysia where I reside. I still wonder where to get the hub. Need to survey around this weekend. The last resort is go to scrap metal shop and find scrap metal sheet, cut, drill and weld as the hub. The big challenge later is to change the sprocket, brake disc, bearing etc when wear and tear. Will need to redo the same stuff.

Same to other part. I had difficulty to look for centrifugal clutch in the past. I purchased one unit outside my place at RM180 (around USD60) lately during my work travelling in Kuala Lumpur which is 1.5 hr travel by flight. I still keep this centrifugal clutch for next design. Could not find the chain, so I asked a machinist to attach the motorbike sprocket (minor modification) and he charged me RM75 (around USD25) which is still costly.

However, I plan to proceed with new design with centrifugal cluch after resolve this back shaft problem. Earlier experience with frequent broken threaded rod was quite painful because need to replace this part again.

I know it is quite challenging doing all these works but I feel lots the excitement after completed it. That is the best part of doing our own design.

 

[landuse]

I know it is quite challenging doing all these works but I feel lots the excitement after completed it. That is the best part of doing our own design.

I agree. The satisfaction you get from looking at something you have done and saying..."Hey I made that"...is really great.

 

[Simon Thomas]

Removal of broken threaded rod

Last Sunday, I managed to remove the broken threaded rod. Now the rear base where I sit the pillow block bearing is empty. I failed to find the hub last weekend here.

My plan to substitute the hub is to use the inner race of a pillow block bearing as the hub. Need to purchase a complete unit of bearing with 1" internal diameter. Later will remove the outer ring with the bearing. I only need the internal ring. Based on the option, that is only available choice and I think it is cheaper than asking a machinist to custom made it for me.

 

[Simon Thomas]

Planned Modified Hub

Something like this.

I will take the inner race and weld to the sprocket and disc brake. If not wide enough, will include the washer in between. The inner race (modified hub) will hold the sprocket and sick brake to the rod later.

Has any of you done this before?

 

[Simon Thomas]

Mild Steel Rod to Substitute the Broken Threaded Rod

This is the look of the 1" diameter mild steel which I purchased from a metal shop which I missed to attach in earlier post. Hope this is strong enough compared with the easily broken threaded rod.

If you have any good or bad experience using the mild steel, please let me know. This is my first time.

 

[Simon Thomas]

Dismantle Bearing Parts and Threaded Rod

Yesterday evening after work, I cut the bearing outer race which I purchased from a bearing shop with grinder. I removed the bearing, retainer and shield. In the same time, I removed all the brake disk, sprocket and pillow block bearing from the broken threaded rod. This is the look.

I will use the inner race and weld as a hub. This is probably cheap way of getting a hub however needs some works to do.

 

[landuse]

Looking good. That 1" rod will do fine.

 

[Simon Thomas]

Thanks Landuse for the review of the rod.

Like you said in earlier post, it is more difficult to remove the welded threaded nut hub from the rod (which I need to improve this method by using key lock system or drill hole penetrate the rod to hook the hub). However, the current parts removal works, I choose to remove this part by part, and bit by bit. I am now left the disc brake to be removed this evening or when I have free time.

 

[Simon Thomas]

Modification Works

Yesterday, I managed to spend some time with my hub modification works.

Here are the photos in next posts from yesterday's works.

 

[Simon Thomas]

Wheel Hub

I welded the bearing inned race to the wheel hub (which I removed from the broken threaded rod).

These are the looks.

 

[Simon Thomas]

Sprocket Hub

This is my modified welded sprocket hub. I used the broken threaded rod as stand to align the position of the welded modified hub. Basically I used 2 types of washers here. One with inner diameter 1" to fit to the rod. While the 2nd one, I used smaller washer to hold the sprocket and hub with screws.

 

[Simon Thomas]

Disc Brake Hub

I used the same method in making of my disck brake hub. Attached are the photos.

 

[Simon Thomas]

Penetration Difficulty

There is one difficulty I encountered during the modification work that is impossible to penetrate the inner race with drill bit (I used the table press drill). Eventhough I scratched the surface so that easy to land the drill bit, however it is still impossible to penetrate. I used a common type of drill bit (which I used to drill mild steel metal), until I broke the drill bit.

Any advice how to drill a hole with this kind of material used as inner race (sorry not so familiar with the material)? It could be hardened steel material from the shiny look.

Please advise if you know. Thanks.